INTERNATIONAL ACCELERATOR RADIOLOGICAL PROTECTION E-MAIL (IARPE) NEWSLETTER "The Official Publication of the Accelerator Section of the Health Physics Society" (with Contributions from International Correspondents) ====================================================================== April 1993 Vol. #2, #3 ====================================================================== OFFICERS ====================================================================== President: Ralph Thomas, LLNL Past President: Wade Patterson, LLNL President-Elect: Geoff Stapleton, SSCL Secretary/Treasurer:Nisy Ipe, SLAC Directors (1 Year): Frank Masse', MIT BATES Paul Neeson, D.O.E. Directors (2 Year): Gerald Fallon, MIT BATES Paula Trinoskey, LLNL Directors (3 Year): Carter Ficklen, CEBAF Jerry Miller, LANL >From the Editor's Terminal (Bob May ) ====================================================================== Please don't miss the important Accelerator Session information in this issue. Again, with apologies to those who contributed, I am unable to reproduce certain material (such as equations) faithfully. It's been suggested that we select a particular information handling format, such as LaTex. Please send your suggestions and preferences to me at the above E-Mail address. If enough people respond, perhaps we can settle on a few suggestions at the business meeting in Atlanta. Thank you all. Bob >From the President ====================================================================== PARIS (AP) _ In a trial that has shocked a nation proud of its "nuclear" advances, three factory directors are charged with exposing untrained workers to radiation that left them horribly burned and mutilated. The accident at Electron Beam Systems, a private company in the eastern town of Forbach, was France's worst "nuclear accident". France's state-owned nuclear-power industry, which produces 75 percent of the nation's electricity, was not involved. But the suffering of the Forbach victims has reminded this country accustomed to nuclear technology of its dangers. Attorneys for the victims accused the defendants in closing arguments Thursday of ``criminal irresponsibility'' for failing to protect workers hired through a temporary employment agency. ``They never told us it was dangerous,'' testified 28-year-old Daniel Leroy, the most badly disfigured victim. ``I'd like to put them against a wall and machine-gun them.'' Manager Patrick Muller, financial backer Philipp Magnen, and Michel Roche, who set up the "nuclear" technology involved in the accident, are charged with involuntarily inflicting injuries on Leroy and two other part-time workers. Government prosecutors have asked that Muller be sentenced to 10 months in prison and fined $2,700. They asked for suspended one-year sentences for Magnen and Roche and the maximum fine of $3,600 each. A verdict is expected in the next few weeks. Civil suits could follow. Leroy suffered second-and third-degree burns on 66 percent of his body as a result of being exposed for 30 minutes to high-level radiation. Sections of his fingers and ears were amputated, and he has undergone multiple skin grafts on his arms, legs and chest. He also lost his hair and is at risk of getting leukemia. Leroy and the two other victims, Giovanni Nespola and Jean-Marc Bies, were part-time workers hired from a temporary employment agency. They were exposed to residual radiation in August 1991 while repairing a conveyer belt in the particle-beam chamber. The chamber was used to transform Teflon, which arrived at the plant in powder form, into a workable material. Safety regulations required the chamber to be shut down for at least 30 minutes before workers entered the area. But the time limit and other regulations requiring danger areas to be clearly marked and workers to undergo extensive training were allegedly ignored by management worried about lost work time. Within a day after performing the repairs, the three men suffered burns on their skin. Within a week, they lost their hair. Their injuries required up to a year of treatment in a specialized burn center in Paris. The $1 million plant was closed by inspectors and courts after the incident, but has since reopened under a new owner. Submitted by, Ralph. H. Thomas, President A WORD ABOUT THE ATLANTA MEETING FROM THE PRESIDENT-ELECT ---------------------------------------------------------------------- I include a detailed program for our technical sessions at Atlanta. First of all I want to say something about the poster sessions and particularly to those few authors who requested oral presentations and who now find they have to make poster presentations. I regret not being able to grant everyone their wishes in this regard but we had restraints on what we could or could not do placed on us by the HPS organising committee. I do believe, however, that in very many regards the poster sessions will be much more effective and I am quite sure that in the out-turn the poster presenters will find that they have a very good deal. I do not think it helpful to go into details of our discussions with the repesentatives of the HPS organising committee but sufficient to say that the program we have is rather better than I had expected. This is of course due to the wonderful response from all our members in submitting such an excellent and varied selection of presentations and not at all to do with my efforts as implied by our President who himself, did much to getting things rolling along. I suspect that the HPS organising committee were a trifle surprised at our wealth of material. Returning to the subject of posters, these must in no way be thought of as being less important than oral presentations. Some institutions use poster presentations as their only vehicle for communications at their conferences so the HPS is only adopting something that is becoming increasingly common nowadays. The important thing is for posters to be properly exploited and we feel that we will do that with the poster sessions firmly in the middle of the day between the morning and afternoon oral sessions. We expect the posters be in the same room as the orals (we expect to use the same room for all our business) and we are devoting an hour and three quarters to 11 poster papers with no other accelerator presentations in parallel, so that should provide excellent opportunities for everyone to get at all the authors. I believe that the authors of posters will have better opportunities of presenting their work than oral authors who will be very firmly constrained to rather brief time slots. Session chairs (what a daft title) who will be very strict but friendly are Ralph Thomas, Bob May, Nisy Ipe and myself. Ken Kase has agreed to make a brief introduction to the poster session. A word about our guest speaker. We are extremely fortunate to get Charles Meinhold to speak to us because he is in great demand at HP functions. I believe that one of the really troubling matters in accelerator HP is what impact the new quantities will have on our practice and so it is extremely valuble for us to hear the rationale for these changes and to have some notion of what the impact is likely to be in the future. Charles Meinhold as I'm sure most of you know is the President of NCRP. An abstract of his talk is given below followed by the detailed technical session as promised. Geoff Stapleton ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ NEW QUANTITIES AND UNIT IN RADIATION PROTECTION AND THEIR IMPORTANCE IN ACCELERATOR HEALTH PHYSICS Charles B. Meinhold (President NCRP) The increasing application of accelerators to medicine, industry and commerce that is probable in the future, coupled with increasing exposure to "accelerator like" radiation environments from, for example, high altitude supersonic air-travel and space-missions make it essential that the practicable systems of dosimetry of these radiation environments be developed. ICRP Publication 60 contains many recommendations of importance for accelerator health physicists. As is well-understood stochastic effects resulting from exposure to ionizing radiation depend upon the quality in addition to quantity of the radiation. This dependancy on quality has been expressed in terms of a quality factor Q and defined as a function of unrestricted linear energy transfer. In its publication 60, ICPR has modified its previous recommendations on the relationship between quality factor Q(L) and the unrestricted linear energy transfer L to take into ccount the higher values of RBE recently measured for intermediate energy neutrons. In place of Q(bar), the quality factor applicable for irradiation of the entire body the ICRP Publication 60 now uses "radiation weighting factors", W(r), based upon biological and other sources of information. Coupled with specific tissue or organ weighting factors W(t) to take account of the variation in stochastic effects in different tissues or organs irradiated, the ICRP has decided to adopt the name effective dose, E, as expressed by: E = "sigma" W(t) x "sigma" {W(r) x D(t,r)} [Editors Note: unable to reproduce equation] where D(t,r) is the the mean absorbed dose in tissue delivered by the radiation. This paper will review these changes and point up their significance for accelerator radiological protection. Charles B. Meinhold ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Alanta Accelerator Session/Section Date: Wednesday, July 14, 1993 Time: 8:30-5:00 Room: Marquis 5 8:30 AM - 9:15 AM Guest Speaker: C. Meinhold 9:15 AM - 9:30 AM Oral Session Session Chairs 1) R. H Thomas 2) R. May Abstract/Paper # Presenter 004/AMD2 E. Brauer 011/AMD3 N. Ipe 068/AMD4 G. Stapleton 155/AMD5 L. Scott 10:15 AM Announcement of start of Poster Session (5 minutes) Introduction: Ken Case Coffee Break 10:15 AM - 12:00 PM Poster Session Abstract/Paper # Presenter 249/AMD6 R. Sit 006/AMD7 H. Kahnhauser 039/AMD8 S. Mao 057/AMD9 R. Sun 150/AMD10 N. Greenhouse 251/AMD11 K. Kase 252/AMD12 M. Grissom 250/AMD13 H. Tran 147/AMD14 J. Liu 091/AMD15 J. McDonald 058/AMD16 C. Greenstock 12:00 PM - 12:30 PM Break 12:30 PM - 1:15 PM Accelerator Section Board Meeting 1:15 PM - 2:15 PM Accelerator Section General Meeting 2:15 PM - 5:00 PM Oral Session Session Chairs 1) G. Stapleton 2) N.E. Ipe Abstract/Paper # Presenter 2:15 PM - 2:30 PM 232/PMD1 A.Fasso 2:30 PM - 2:45 PM 290/PMD2 R.Thomas 2:45 PM - 3:00 PM 248/PMD3 K.Millage 3:00 PM - 3:15 PM 100/PMD4 J.Bull 3:15 PM - 3:30 PM 099/PMD5 S.Baker 3:30 PM - 4:00 PM Coffee Break 4:00 PM - 4:15 PM 045/PMD6 M.Torres 4:15 PM - 4:30 PM 007/PMD7 S.Musolino 4:30 PM - 4:45 PM 154/PMD8 L.Walker 4:45 PM - 5:00 PM 156/PMD9 M.Marceau-Day COURSE ANNOUNCEMENT ===================================================================== INTERNATIONAL UNIVERSITY AT JOINT INSTITUTE FOR NUCLEAR RESEARCH JINR TRAINING CENTER 1 9 9 3 TRAINING COURSES ON RADIATION PROTECTION physical, medicobiological, ecological aspects (Chernobyl disaster and its lessons) Dubna - Russia 12.07 - 22.08 - 1993 REPRINTED FIRST ANNOUNCEMENT ------------------- The Joint Institute for Nuclear Research (JINR) in Dubna, Russian Federation, is organizing a new International University. The goal of this University is the preparation of highly qualified specialists on the base of research facilities of JINR, the available infrastructure of the city of Dubna, and already successfully operating JINR Training Center. In 1993 within the framework of the International University it is planned to realize a special 6-week programme on "Radiation Protection"(Chernobyl disaster and its lessons). Series of lectures, seminars, practical work will be included in the programme. Some excursions to the Atomic Industry enterprises are foreseen. The preliminary programme is: 12 July - 25 July Option A: Types of ionizing radiations and their interaction with the matter; Physical aspects of radiation protection; Advance in radiation monitoring; Dosimetry of mixed radiation; Metrology of ionizing radiation; Ecological consequences of the Chernobyl NPP accident; IAEA basic safety standards on radiation protection; Basic concepts of radiation protection; 26 July - 8 August Option B: DNA damages and cell radiosensitivity; DNA repair processes; Radiation mutagenesis; Radiation induced effects and microdosimetry; Low doses of irradiation. 9 August - 22 August Option C: Irradiation of population and consequences; Assessment of doses; Countermeasures in plant production; Animal farming and countermeasures; Aquatic ecosystems and countermeasures; Medical aspects of irradiation. Prominent scientists from UNESCO, IAEA, European Physical Society, Russian Academy of Sciences, Russian Engineering Academy, Russian Research Centre "Kurchatov Institute", specialists from the Russian Ministry of Science, the Russian Ministry of Atomic Energy and others will be invited to participate. The working language is English. The programme is intended for senior students, post-graduate students, young scientists, assistant professors of corresponding disciplines. Exhibitions of equipment in accordance with subjects of the Courses will be organized. ABOUT THE TOWN: Dubna is a quiet and pleasing town lying 132 km north of Moscow on the picturesque banks of the Russian river Volga. Its surroundings offer peaceful rural scenery which, though having no famous monuments, keeps memories of the past, now peaceable, now stormy. A two hours` trip brings you to Moscow, the capital of Russia, to Sergiev Posad, the centre of the Russian Orthodox church with its 500-year-old Trinity Monastery, a witness of great events, and to other places of interest on this old Russian territory. Three days "Golden Ring" tours (at the expense of participants) after series of lectures will be arranged. REGISTRATION FEE: Registration fee for the courses is US$ 150.-, it includes: - full pension for 14 days - party - excursion to Sergiev Posad - transportation from Moscow airport or railway station. The Organizing Committee has at its disposal a limited fund for financial support; if you are planning to use it, contact the Organizing Committee as soon as possible. Attendance of accompaning persons is at their own expense. Only those who have returned the accompanying questionary will receive the second announcement. It will contain more information on the scientific programme, organization, accomodation, visa, payment etc. A detailed programme will be given in the final announcement. INTERNATIONAL ADVISORY COMMITTEE: Barjahtar V.G. Litchinitzer M.R. Belyaev S.T. Michailov V.N. Danilov-Danilian V.I. Nechaev E.A. Dudak F. Okolovich V.N Hrynkevitch A. Piragino G. Jacob M. Rjabchenko S.M. Janouch F. Saltykov B.G. Kadyshevsky V.G. Shumeiko N.M. Karlov N.V. Ward Th.E. Krasnikov Ju.G. ORGANIZING COMMITTEE: Aleinikov V.E. Ivanova S.P. Krasavin E.A. Petrosyan V.S. Romanov A.I. Roussakovitch N.A. Sarantsev V.P. Sissakian A.N. - Chiarman Skiba L.P. INFORMATION: Secretariat: Ms. Larisa Skiba 141980 Dubna Moscow Region Joint Institute for Nuclear Research telex: 911621 DUBNA SU fax: (095)-975-23-81 telephone:(095)-420-20-74 e-mail:skiba@ssd.jinr.dubna.su NEWS FROM IARPENL CORRESPONDENTS ====================================================================== News from CEBAF (Bob May ) ---------------------------------------------------------------------- CEBAF Pre-Operations Testing Update On April 9, CEBAF accelerator operators completed a 4 1/2 month round of pre-operations testing approved through the Accelerator Readiness Review process. While installation proceeded in the rest of the accelerator and in the end stations, CW beam at up to 120 MeV was run in the north linac and its spreader/extractor region, and the east arc was operated with beam at low average current. The purposes of the tests were to integrate and validate accelerator systems, to gain valuable operating experience and training, and to identify areas needing attention before commissioning, scheduled to begin in 1994. Noteworthy aspects of the testing included the following: -The linac was run at relatively high current (> 100 microamperes) for extended periods. This demonstrated the accelerator's substantial inherent operating stability, given the minimal involvement of active correction mechanisms, which are still being implemented and refined. -The effects of heavy beam loading on an rf control module were tested extensively and successfully through the use of an artificially modified waveguide, designed to replicate the beam loading in the planned five-pass operation. -The high-precision calibration of rf control modules was demonstrated. It was shown that after replacement of a module, the beam could be returned with great precision to its previous state. -During the testing one cryomodule was run with an energy gain above 32 MeV -- 160% of specification -- indicating not only absence of arc trips, but also showing that an accelerator final energy substantially higher than the specified 4 GeV may well be attainable. -A precise method was demonstrated for measuring the isochronicity of beam transport through the recirculation arcs, the degree to which rays of different momenta are synchronized upon emerging from the arc. The isochronicity was shown to be better than needed. -For both the linac and the arc, optics tune-up procedures were developed. In a useful application of CEBAF beam during the testing, a team from the University of Virginia was helped in its effort to irradiate material for a polarized target without inducing radioactivity in the material. CEBAF's high current allows irradiation of target material at low energy, below the threshold of neutron production. A 5 MeV beam was used to create the required paramagnetic centers in ammonia. It is expected that in the future this unique capability will be called on increasingly. Steve Corneulissen News from CERN (Manfred Hoefert ) ---------------------------------------------------------------------- The measurement of dose equivalent in stray radiation fields outside the shielding of high energy accelerators had always been one of the main interests at CERN in the past. New interest arose to resume such measurements with the change of quality factor to radiation weighting factor by ICRP. CERN's Radiation Protection Group made a research proposal to the CEC (Commission of the European Community) on the: "Measurement of dose equivalent in relativistic stray radiation fields" claiming that such an activity would be in particular benificial for a better understanding of the dosimetry of air craft pilots. The proposal was accepted by the CEC as research contract PL920173 under the Radiation Protection Research Action 1992-1993 with Prof. Ian McAuley of the University of Dublin, Trinity College, as the co-ordinator. In the framework of the above project the Radiation Protection Group of CERN will provide the stray radiation fields during three irradiation periods in 1993. These stray fields outside the shielding enclosure of a secondary hadron beam are produced by hitting a thick target with positive or negative hadron beams from the SPS accelerator. The resulting fields have different spectral compositions according to different shielding configuration surrounding the target. They are of a pulsed structure with radiation spills of about 2 seconds arriving with a repetition rate of 14 seconds. Presently the Group is working on the problems of beam monitoring so that information can be made available to all participants during the experimental periods for normalizing their results. In addition the Group will try to provide a field mapping of the sites chosen for the exposure of instruments and passive detectors. Furthermore, the Group's own contribution to the project consists in performing neutron spectroscopy using Bonner spheres that will be supplemented for energies above 10 MeV by adding threshold detectors. These measurements will be accompanied by Monte Carlo calculations, the results of which should help to describe the field composition at the sites chosen for the exposures. If manpower permits a special instrument to measure dose equivalent available at CERN, the recombination chamber REM-2, will be employed. Finally the Group possesses a TEPC that would be used if no other participant proposes such an instrument. The following periods for the experiments now figure on the official schedule of the CERN accelerators for 1993: 1: From 3 May at 8.00 hours to 5 May at 6.00 hours and 5 May 20.00 hours to 7 May at 8.00 hours: This period will essentially be used by RP-Group in collaboration with the accelerator people to set up a beam of 125 GeV/c hadrons. The yield of stray radiation outside the shield will be studied both for positive and negative beam polarity. The beam monitoring will be tested. No beam stability is guaranteed in the beginning of the run but towards the end of the period there could be stable conditions suited for the exposure of passive detectors. 2: From 23 July at 8.00 hours to 26 July at 8.00 hours: During this period beams of positive hadrons up to 200 GeV/c are possible. This condition will provide the highest dose rates outside the shield such that integrating detectors could accumulate doses rapidly while active detectors (rem counters) may suffer from signal pile up due to the pulsed characteristic of the radiation field. However, the intensity can always be lowered. 3: From 23 September at 8.00 hours to 28 September at 8.00: This last five day period is considered as the time mostly suited for participants from outside CERN and will be devoted to their particular needs. Due to technical reasons beams will only run at energies of about 125 GeV/c but at the highest possible intensities in particular when needed for the exposure of passive detectors. Please note: Although the periods are fixed on the official schedule of the SPS operation no guarantee can be taken for the times and the actual duration of the runs for reasons that are purely technical: a complicated machine like the SPS proton accelerator is not a X-ray tube. Manfred Hoefert News from LBL (Rick Donohue ) ---------------------------------------------------------------------- The Advanced Light Source (ALS) has reached it's design current of 400 mamps. Lifetimes are currently less than 1 hour due to high vacuum pressure (few x 10^-7 torr). Lifetime will greatly increase as the design pressure of 1 ntorr is reached. Commissioning will continue through the end of the month followed by a 2 month shutdown. Publications: S. Chatterjee, R. J. Donahue, "EGS_Windows2: An enhanced Graphical Interface to EGS", LBL-33429/UC-400, January (1993). Rick Donahue News from FRASCATI LNF (Adlofo Esposito ) ---------------------------------------------------------------------- New internal reports from Frascati LNF are available. These reports may be requested from A. Esposito. A.FERRARI,M.PELLICCIONI,P.R.SALA Bremsstrahlung source terms for intermediate energy electron accelerators LNF-92/102(p) A.FASSO' AND M.PELLICCIONI Evaluation of radiation skyshine from the Main Rings of the DAFNE project LNF-92/111(IR) A.FASSO' AND M.PELLICCIONI Evaluation of radiation skyshine from the Damping Ring of the DAFNE project LNF-92/112(IR) Adolfo Esposito News from SLAC (Vashek Vylet ) ---------------------------------------------------------------------- ********************************************************************** !! Gas-bremsstrahlung neutrons measured in synchrotron line at SSRL !! ********************************************************************** We have measured photoneutrons produced by high-energy x-rays striking various devices in Beamline-5 at the SSRL. Beamline-5 is an undulator line having a 4-meter long straight section. With a vacuum of 1.E-9 torr and 100 mA of 3 GeV electrons, we measured both scattered photons and neutrons, the latter a factor of twenty above background. These measurements were motivated by a recent series of calculations aimed at quantifying the scattered photon and neutron dose rate caused by gas bremsstrahlung. An EGS4 User Code, developed specifically for this purpose, allows the user to read in a multi-cylinder/slab geometry and a set of photoneutron cross sections in order to obtain Monte Carlo estimates. We think that this should make life easier for those of you who need to better understand the scattering of photons (>1 keV), as well as the production of neutrons, from such beamline components as safety shutters, beamstops, monochrometers, mirrors, etc. Details of the calculation methods and the experimental verification will be presented at the HPS meeting in Atlanta. (Message from James Liu and Ralph Nelson at SLAC: james@slac.stanford.edu and wrnrp@slac.stanford.edu) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ The following announcement will be of interest to colleagues living in the San Francisco Bay Area: The Radiation Physics Department and ES&H Division at SLAC are organizing a series of seminars covering subjects related to radiation protection, nuclear medicine, radiation biology or even broader issues related to particle accelerators or science in general. The talks will be given, with a few exceptions, on the fourth Tuesday of the month in the Orange Room at SLAC, from 4 to 5 PM. Distinguished speakers from the Bay Area and elswhere have already promissed their participation in the series: May 4 1993 Mark Bodnarczuk (NREL, CO) May 25 1993 Yoshi Namito (KEK, Japan) June 15 1993 Helen Nuckolls (SLAC, CA) Sept 28 1993 Ralph Thomas (LLNL, CA) Oct 26 1993 Pat Durbin (LBL, CA) Nov 30 1993 Lynn Anspaugh (LLNL, CA) For more information please contact the Radiation Physics secretary Digna Lacey at (415) 926-3093, or Vashek Vylet at (415) 926-2048. Vashek Vylet FEATURE PRESENTATION ====================================================================== The CALOR93 Code System T.A. Gabriel Oak Ridge National Laboratory ABSTRACT A brief history and description of the CALOR93 code system which is used for detector (calorimeter) design and analysis, in particular and radiation transport in general, is presented. I. INTRODUCTION The purpose of this paper is to describe a program package, CALOR93 that has been developed to design and analyze different detector systems, in particular, calorimeters which are used in high energy physics experiments to determine the energy of particles. Calorimeters are an important tool in high-energy experimental physics. One's ability to design a calorimeter to perform a certain task can have a strong influence upon the validity of experimental results. The validity of the results obtained with CALOR93 has been verified many times by comparison with experimental data. The codes <9HETC93, SPECT93, LIGHT, EGS4, MORSE, and MICAP) are quite generalized and detailed enough so that any experimental calorimeter setup can be studies. Due to this generalization, some software development is necessary because of the wide diversity of calorimeter designs. The CALOR code system for analyzing detectors for high energy physics research 000was first distributed in the early 70s.(1) At that time, the code system consisted of HETC (2), ELPHO, and SPECT, and was considered to be a benchmark for particle cascade calculations. HETC is the high energy transport code for protons, neutrons (E>= 20 MeV), charged pions and muons. This code was originally designed for accelerator shielding studies, but it soon become apparent that the code which is mostly analog in its makeup could be used in detector studies; i.e., calorimeter design. ELPHO is an old obsolete electromagnetic transport code which can operate as a stand-alone code or can track the gamma rays and e generated in HETC (Ed. Note - characters not reproducible). SPECT is not a transport code but analyzes data generated by the HETC code. Energy deposition data is calculated by this code, and in a user-written subroutine, is stored in appropriate data arrays. For scintillator or ionization systems, saturation and/or recombination effects can be included during the SPECT analysis using the LIGHT program. During the middle and latter 70s, with the introduction of high-Z materials into calorimeters, Pb, W, U, etc., low-energy neutrons and gamma rays become an important topic in hadronic shower development.(3) To better understand the importance of these low-energy particles, the MORSE (4) Monte Carlo code was added to the CALOR system to track low-energy neutrons generated during the transport of the high-energy particles in HETC. Many calorimeter studies (5) at this time were carried out with this code system; i.e., HETC, ELPHO, SPECT, and MORSE. Studies of many different calorimeters revealed discrepancies in code methods. Generally, each of these discrepancies could be traced to one or another of the codes. The ELPHO code could not satisfactorily explain many physical phenomena, for example, the e/u ratio, electromagnetic detector resolution, high-Z material shower suppression, etc., and therefore was discarded in favor of the EGS (6) system which included a much more complete description of the physics in electromagnetic showers and could satisfactorily explain the above quantities. The use of the EGS system started during the latter part of the 70s and early 80s. The CALOR code system - HETC, EGS, SPECT, and MORSE - continued in use until the present and now is continually undergoing additional updates and improvements. Since MORSE is not an analog transport code, it could only be used to approximate energy deposition at each collision site. This deficiency and others have now been overcome by the creation of a new analog transport code MICAP (7) which can, if necessary, replace the MORSE code in any of the calculations. It had already been confirmed by comparison with data that the old CALOR code system could not accurately reproduce detector resolutions and radial shower spreads at very high energies >= 30 GeV. This discrepancy was traced to the high-energy collision model that is used in HETC. This collision model, which scales data generated at 3 GeV to higher energies. underestimated at energies >= 20-30 GeV the amount of energy going into the electromagnetic channel and progressively overestimated the hadronic component. The collision model was originally developed for shielding studies and, fortunately, this type of error would leade to a slight overestimation of the amount of shielding necessary; i.e., the error is on the conservative side. to correct this deficiency, a new high-energy collision model based on the work of Capella and Tran Thanh Van (8,9) was incorporated into the HETC code. With the completion of this task, CALOR93 has been a firm theoretical base ranging in energy from approximately 20 TeV to 1E-03 eV and will be able to satisfy many probelms associated with SSC detector design and radiation damage and protection studies. In the mid 80s, a paper was presented detailing the underlying mechanisms of compensating calorimetry. (10) From previous presentations and publications, (11, 12) it was recognized at that time that this new understanding would be met with much skepticism within the high-energy physics community. At that time, the following critical points were deduced following substantial analysis of various calorimeter systems utilizing the CALOR system:13 1. prior to later experimental confirmation, it was pointed out that current designs of uranium liquid argon calorimeters were not fully compensating; (10, 11, 12, 14, 15) 2. the importanct of the hydrogen content in the active medium to couple the low energy neutrons to the output signal was stressed; (10, 11, 12, 14, 15) 3. the significant role of "electromagnetic sampling inefficiencies" (which are the result of preferential photon absorption16 and electron multiple scattering in the high-Z inactive material (12, 15)) in reducing the ratio of electron to hadron response was expalined; (10, 11, 12, 14, 15) 4. the importanct of the saturation of signal in the regions of high density energy deposition was emphasized; (10, 11, 12, 14, 15) and 5. these new understandings led us to "predict that a lead calorimeter may also give EM/HAD ~ 1", (17) where EM/HAD is the ratio of average electron-to-hadron response for the same incident kinetic energy, hereafter referred to as the e/h ratio. In other words, a compensating lead calorimeter was predicted. As a result of these predictions, experimental programs (for example, (18) SLD and DO uranium liquid argon and uranium-scintillator tests) directed their efforts at proving or disproving the above conclusions. After much experimental testing and reviewing, as well as additional analytical efforts, (19, 20) during the past several years, this skepticism has evolved into a general acceptance by the community of this new understanding of compensating calorimetry.(21) This new enlightenment was a direct result of having in hand code system, CALOR, (13) which contained as good a description of the current physics of calorimetry as possible. However, there is still substantial room for improvements in all calorimeter code systems. Current and future improvements in these code systems will provide additional returns through better designs of calorimeters, as well as a better understanding of the physics processes at SSC energies. II. A BRIEF DESCRIPTION OF THE CODES IN THE CALOR SYSTEM The three-dimensional multimedia high-energy nucleon-meson transport code HETC93 (22) is used, with modifications, to obtain a detailed description of the nucleon-meson cascade produced ioon absorbers. This Monte Carlo code takes into account the slowing down of charged particles via the continuous slowing-down approximation, the decay of charged pions and muons, inelastic nucleon-nucleus and charged-pion-nucleus (excluding hydrogen) collisions through the use of an intermediate-energy intranuclearcascade evaporation (MECC) model (E <3 GeV), a scaling model (3 GeV=15 GeV), and inelastic nucleon-hydrogen and charged-pion-hydrogen collisions via the isobar model (E<3 GeV), and a fragmentation model (E>3 GeV). Also, accounted for are elastic neutron-nucleus (E<100 MeV) collisions, and elastic nucleon and charged-pion collisions with hydrogen. The intranuclear-cascade-evaporation model as implemented by Bertini is the low energy heart of the HETC code. (23) This model has been used for a variety of calculations and has been shown to agree quite well with many experimental results. The underlying assumption of this model is that particle-nucleus interactions can be treated as a series of two-body collisions within the nucleus and that the location of the collision and resulting particles from the collisions are governed by experimental and/or theoretical particle-particle total and differential cross-section data. The types of particle collisions included in the calculations are elastic, nonelastic, and charge exchange. Thos model incorporates the diffuseness of the nuclear edge, the Fermi motion of the bound nucleons, the exclusion-principle, and a local potential for nucleons and pions. The density of the neutrons and protons within the nucleus (which is used with the total cross sections to determine interaction locations) are determined from the experimental data of Hofstadter. (23) Nuclear potentials are determined from these density profiles by using a zero-temperature Fermi distribution. The total well depth is then defined as the Fermi energy plus 7 MeV. Following the cascade part of the interaction, excitation energy remains in the nucleus. This energy is treated by using an evaporation model which allows for the emission of protons, neutrons, d, 3He, a, and t. Fission, induced by high- energy particles, is accounted for during the phase of the calculation by allowing it to compete with evaporation. Whether or not a detailed fission model is included has very little effect on the total number of secondary neutrons produced. In recent years, a large amount of experimental and theoretical work has been done, and more reliable models are now available for the description of high energy (>=5-10 GeV) hadron-proton and hadron-nucleus collisions. In particular, a multi-chain fragmentation model of hadron-nucleus collisions has been developed and implemented into a Monte Carlo code by J. Ranft et al., (24) following the work of A. Capella and J. Tran Thanh Van. The version of the model that is used in the work reported here, with some modifications, is that provided by the transport code FLUKA87. The modifications that have been made are mostly those necessary to predict such things as residual nuclei and excitation energies. (25) This information is needed in HETC for evaporation calculations which yield the production of low-energy neutrons, protons, deuterons, alpha particles, etc. At high energies, a complete intranuclear cascade does not develop when a nucleon is hit by a hadronic projectile inside the nucleus. The time-scale governing typica hadronic interactions is very long and therefore the most energetic secondaries are actually produced as the jet decays beyond the target nucleus and therefore have no chance of re-scattering. Fragmentation of the jets in the jet C.M.S. is carried out with possible formation of 180 stable particles or resonances. (26) The resonances decay with either two-body isotropic decay or three-body decay. Experimental decay products and branching ratios are input (27) to the code so that all quantum numbers are conserved. In this way, exclusive events are generated, and correlation studies can be carried out. All particles produced in the fragmentation of the jets are assumed not to interact with the nucleus. The source distribution for the electromagnetic cascade calcula- tion is provided by HETC; it consists of direct photon production from hadron-nuclear collisions, photons from neutral pion decay, electrons and positrons from muon decay (although this is usually not of interest in calorimeter calculations because of the long muon lifetime), de-excitation gamma rays from nonelastic nuclear collisions and fission gamma rays. Since the discrete decay energies of the de-excitation gammas are not provided by HETC and only the total energy is known, individual gamma energies are obtained by uniformly sampling from the available energy until it is completely depleted. The transport of the electrons, positrons, and gammas from the above sources is carried out using the EGS system. (6) Neutrons which are produced with energies below 20 MeV are transported using the MORSE (4) or MICAP (7) Monte Carlo transport codes. The neutron cross sections used by MORSE or MICAP are obtained from ENDFB/V. Gamma rays (including those from capture, fission, etc.) produced during this phase of the calculations are stored for transport by the EGS code. The MORSE code was developed for reactor application. The MICAP code was developed specifically for detector analysis. Both codes can treat fissioning systems in detail. This ability is very important since a majority of the fissions results from neutrons with energies less than 20 MeV. Time dependence is included in MORSE and MICAP, but since neither HETC nor EGS has a timing scheme incorporated, it is generally assumed that no time passes for this phase of the particle cascade. Therefore, all neutrons below 20 MeV are produced at t = 0. General time cuts used in the MORSE or MICAP codes are 50 ns for scintillator and 100 ns for TMS or Argon. the non linearity of the light pulse, L, in scintillator due to saturation effects is taken into account by the use of Birk's law (28) where the light emission per unit path length is given by dL/dx proportional to (dE/dx)/(1+kB(dE/dx)) [Ed. Note original equation not reproducible] and kB is the saturation constant and dE/dx is the ionization and excitation energy loss per unit path length. For plastic scintillator kB is generally between 0.01-and 0.02-g/(cm^2 MeV). A similar law is assumed to apply to the charge collected in ionization detectors. This takes into account the loss of signal resulting from recombination effects in the ionization column. (29) For electrons at all energies, it is assumed that kB = 0. The Cerenkov response can be obtained from the following equations: dI/dx = [(4pi^2 e^2 Z^2)/(h c^2)] delta v [1-(1/B^2 n^2)] [Ed. Note original equation not reproducible] where dI/dx = the number of photons emitted per unit path length, delta v = the frequency interval of the photons, Z = the charge of the particle, B = the velocity of the particle relative to light velocity c, n = the index of refraction of the medium in the frequency interval considered dE/dx = the ionization and excitation loss and e,h,c = the electronic charge, Plank's constant and the speed of light, respectively. The non uniformity of light collection can be taken into account by weighting the light pulse by spatially-dependent weight factors. These factors can be determined experimentally or calculationally using Monte Carlo techniques. III. SUMMARY CALOR93, like it predecessors will continue to produce detailed radiation transport information for calorimeter designers as well as for shielding designers and will continually be updated for future calculations. IV. ACKNOWLEDGMENTS Many people have contributed to the CALOR system. A few of the more recent ones are listed below: F.S. Alsmiller, Oak Ridge National Laboratory R.G. Alsmiller, Jr., Oak Ridge National Laboratory J. Brau, University of Oregan T. Handler, University of Tennessee, Knoxville P.K. Job, Argonne National Laboratory J.O. Johnson, Oak Ridge National Laboratory B. Moore, University of Mississippi C. Zeitnitz, University of Arizona REFERENCES 1. T.A. Gabriel and K.C. Chandler, Particle Accel. 5, 161 (1973) 2. K.C. Chandler and T.W. Armstrong, Oak Ridge National Labora- tory Report, ORNL-4744 (1972) 3. C.W. Fabjan et al., Nucl. Instrum. & Methods 141, 61 (1977) 4. M.B. Emmett, Oak Ridge National Laboratory Report, ORNL-4972 (1975) 5. T.A. Gabriel, Nucl. Instrum. & Methods 150, 146 (1978) 6. R.L. Ford and W.R. Nelson, Stanford University Report, SLAC-0210 (1978) 7. J.O. Johnson and T.A. Gabriel, Oak Ridge National Laboratory Report, ORNL/TM-10196 (1987) 8. A. Capella and J. Tran Thanh Van, Phys. Letts. 93B, 2, (June 2, 1980) 9. P.A. Aarnio et al., CERN TIS Divisional Report, TIS-RP/ 106-ReV (1984) 10. T.A. Gabriel et al., "Compensation Effects in Hadron Calori- meters," IEEE Trans. Nucl. Sci. NS-32, 1 (1985) 11. J.E. Brau and T.A. Gabriel, SLD - New Detector Note No. 119, May 22, 1984 12. J.E. Brau, "Monte Carlo Investigation of Compensation in Uranium Calorimeters," Proceedings fo the September 1984 Seattle Meeting of the SLD Collaboration. 13. T.A. Gabriel, "Codes, Models, and Cross Sections for Use in Analyzing Compensated Calorimeters," Proceedings of Workshop on Compensated Calorimetry, Pasadena (1985) CALT-68-1305. 14. J. Brau and T.A. Gabriel, "Monte Carlo Studies of Uranium Calorimetry," Nucl. Instrum. & Methods, Vol. A238, p. 489, 1985 15. J. Brau, "A Monte Carlo Investigation of Compensation in Uranium Calorimeters," Proceedings of Workshop on Compensated Calorimetry, Pasadena (1985) CALT-68-1305. 16. P.M. Mockett, Proceedings of the 11th SLAC Summer Institute on Particle Physics, July 1983, Ed. Patricia M. McDonough, SLAC-267, 1984. 17. H. Gordon and P. Grannis, "Calorimetry for the SSC," Proceedings of the 1984 Summer Study on the Design and Utilization of the SSC, Snowmass, Colorado, 1984, p. 591. 18. See Proceedings of Workshop on Compensated Calorimetry, Pasadena, California, 1985, CALT-68-1305. 19. H. Brueckmann, "Hadron Calorimetry - A Puzzle of Physics, Proceedings of Workshop on Compensated Calorimetry, Psasdena, 1985, CALT-68-1305. 20. R. Wigmans, "On the Energy Resolution of Uranium and Other Hadron Calorimeters," Nucl. Instrum. & Methods, Vol. 259 p. 389, 1987. 21. J.E. Brau and T.A. Gabriel, "Theoretical Studies of High Luminosity, High Energy Collider," presented at the International Conference on Advanced Technology and Particle Physics, Como, Italy, June 15, 1988, and published in Nucl. Instrum. & Methods. 22. R.G. Alsmiller, Jr., F.S. Alsmiller, and O.W. Hermann, "The High-Energy Transport Code HETC88 and Comparisons with Experimental Data," Nucl. Instrum. & Meth. in Phys. Res., A25, p. 337-343 (1990) 23. F.S. Alsmiller and R.G. Alsmiller, Jr., "Inclusion of Correlation's in the Empirical Selection of Intranuclear Cascade Nucleons from High-Energy Hadron-Nucleus Collisions," Nucl. Instrum. & Method. in Phys. Res., A278, p. 713-721. 23. H.W. Bertini, Phys. Rev., Vol. 188, pg. 1711, 1969. 24. P.A. Aarnio et al., CERN TIS Divisional Report, TIS-RP/ 106-ReV, 1984. 25. F.S. Alsmiller et al., "Low-Energy Particle Production from High-Energy hadron-Nucleus Collisions," Proceedings of Conference on Theory and Practices in Radiation Protection and Shielding, Knoxville, Tennessee, April 22-24, 1987. 26. S. Ritter and J. Ranft, Acta Physica Polonica, Vol. B11, 1980. 27. K. Hanbgen and S. Ritter, Karl-Marx Universitat, Leipzig, DDR, KMU-HEP 8301, 1983. 28. J.B. Birks, Proc. Phys. Soc., Vol. A64, p. 874, 1951. 29. A. Babaev et al., Nucl. Instrum. & Methods, Vol. 160, p. 427, 1979. EMPLOYMENT OPPORTUNITIES ====================================================================== Health Physics positions open at SLAC. Radiation Surveys and Operations Group Leader Duties: Develop programs and write procedures for the control of exposure to ionizing radiation and the control of radioactive materials: A) Radioactive materials and waste--material surveys, material storage, inventory, procedure development, liaison with waste vendor, material characterization, sealed source program, radioactive material shipping and receiving; B) Nuclear materials representative-- maintains inventory, produces appropriate transaction decay and material balance reports. Make and interpret radiation measurements. Includes the operation and cal- ibration of multichannel analyzers, GM and ionization chambers, ultra high purity germanium detectors. OHP representative to SSRL: Health Physics service to SSRL, procedure development to ensure SSRL consistency with SLAC Radiation Safety Program. Assemble and test equipment for planned measurements and experiments. Supervise and conduct health physics operational surveys of accelerator areas, components, laboratories and radioactive sources/use areas: A) Technician Level Services--accelerator surveys, instrument calibration, procedure development, radiation physics support, non-ionizing radiation surveys; B) Environmental Monitoring--environmental TLD, water analysis and other media as necessary. Plan/coordinate entries into radiation areas with emphasis on ALARA principles in conjunction with an understanding of the physical processes producing the radiation field and the effects of existing shielding. Also manage the Irradiation Service: Coordinate Radiological Calibration Facility (RCF) use activities for experimenters as well as routine instrumentation calibrations. Supervise the activities of the Radioactive Materials Manager and the Radiation Surveys Manager and their technical staffs. Skills/Experience: The applicant must understand the use of equipment for radiation monitoring such as electrometers, proportional counters, scintillation counters and ionization chambers. Must have a M.S. level education in Health Physics or greater and several years of experience in a comprehensive radiation safety program. Must be able to work independently with little or no direct supervision from the OHP head. Must be able to set work priorities to mutually benefit management, workers and other SLAC departments. Must work well in interdisciplinary mode in the ES&H division. Must be able to interface with professionals in all parts of SLAC and SSRL. Must be able to converse, report to, and work with regulatory agencies on the Federal, State, and local level. Must deal with peers at other DOE facilities as well as a variety of commercial vendors. Must be able to plan, schedule, and assign work for other professional level employees as well as technicians. Supervision is a key element of performing the group's mission. Must be willing to perform labor-type duties. Must have no permanent handicaps that would preclude one from doing surveys or any type of field work. Applicant must be willing to learn to use the SLAC computer system. Applicant must have good communication skills, both written and oral. This position is classified as a Health Physicist III, with a starting monthly pay range of $3,830 to $6,631. Refer to Job #16059. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Health Physics Training Manager Duties: Responsible as the Manager for Health Physics Training in the Operational Health Physics (OHP) Department. The work includes providing most of SLAC's radiation protection training to include general employee, radiation worker 1, radiation worker 2, radiological controls technician, and professional health physics refresher courses. Plans, prepares, and conducts training in radiation protection for laboratory and contractor employees. Provides assistance to the training coordinator in the scheduling and control of radiation protection training programs for all of the worker populations. Maintains knowledge of training requirements listed in DOE Orders and other mandatory compliance documents, e.g., the DOE Radiological Control Manual, and informs both support and programmatic managers of training requirements. Creates or helps develop and maintain computerized training record data bases for training conducted in the radiation protection field. Audits training programs conducted by other laboratory organizations to ensure regulatory compliance, e.g., Radiological Work Permit radiation protection job specific training. Participates in initial and refresher training to maintain currency in subjects to be taught. Periodically assists in OHP activities to maintain currency in radiation protection practices and policies. Participates in DOE Training Resources and Data Exchange (TRADE) activities. Skills/Experience: Training at the M.S. level or higher in Health Physics or a related Engineering or Physical Science program with some coursework in Health Physics with at least 3 years of operational health physics experience in dosimetry systems or at the B.S. level in the above disciplines and with 5 years of operational health physics experience. Must be able to supervise technical radiation protection staff. Must have sufficient understanding of the underlying principles of health physics, radiation protection theory and practice and the measurement and analysis of ionizing radiation and radioactivity. Should be computer literate (IBM PC systems preferred) and must be willing to learn the SLAC mainframe computer system (VM). Must have good communication skills, written and oral. Extensive experience in presentation of courses of instruction, public information responsibilities or tutoring required. This position is classified as a Health Physicist II, with a starting monthly pay range of $3,283 to $5,481. Refer to Job #16056. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ SLAC offers excellent benefits including generous vacation and tuition grants for children. For immediate consideration, send your resume, indicating appropriate Job Number, to SLAC; P.O. Box 4349, M/S 11, Stanford, CA 94309, Attn: Larry Peckler. Equal opportunity employer through affirmative action. Mike Grissom, SLAC FROM THE MEMBERSHIP ====================================================================== A request... ---------------------------------------------------------------------- Date: 5/1/93 3:20 AM From: PAYNE.MELONIE@FORUM.VA.GOV I NEED SOME INFORMATION REGARDING SIEMENS SELF-SHIELDED CYCLOTRONS. I NEED TO KNOW WHO OUT THERE HAS ONE, WHAT KIND OF SHIELDING YOU HAD PUT IN, WHAT KIND OF EXPOSURE RATES YOU GET IN UNRESTRICTED AREAS AND WHAT ARE THE FINISHED DIMENSIONS OF THE CYCLOTRON ROOM. ALSO, ANY OTHER INFO OR SUGGESTIONS FROM THE H.P. PERSPECTIVE WOULD BE GREATLY APPRECIATED. THANKS. SEND MESSAGE OR CALL ME AT (313)761-7916. More cartoon physics... ---------------------------------------------------------------------- Cartoon Law II. Any body in motion will tend to remain in motion until solid matter intervenes suddenly. Whether shot from a cannon or in hot pursuit on foot, cartoon characters are so absolute in their momentum that only a telephone pole or an outsize boulder retards their forward motion absolutely. Sir Isaac Newton called this sudden termination of motion the stooge's surcease. Thanks to Suzie Thomas for the physics hy-jinx. CLOSING THOUGHTS ====================================================================== Problems are the necessary hurdle between vision and reality. Charles Simpson