INTERNATIONAL ACCELERATOR RADIOLOGICAL PROTECTION (IARPE) NEWSLETTER FEBRUARY 1992 FROM THE EDITOR'S TERMINAL (Nisy Ipe ) ========================================================================= Last week, as we in the U.S. observed President's Day, the words of President John F. Kennedy (during his memorable inaugral address) echoed through my mind "..ask not what your country can do for you - ask what you can do for your country". And so, my fellow IARPERs, ask not what the newsletter can do for you - ask what you can do for the newsletter. Words cannot express my gratitude to our correspondents who have once again provided the contributions to the newsletter in a timely manner. I am soliciting feature articles (maximum length = 3 pages, minimum length = 1 page, horizontal length = 70 characters) for the newsletter. The next issue, for instance, will have a feature article on the SSC. You may send the article directly to me by E-Mail, or send it through your correspondent. Note: IARPER = International Accelerator Radiological Protection E-Mail Reader NEWS FROM CERN (Alberto Fasso' ) ========================================================================= Dismantling of the neutrino cave has started. The beryllium target and part of the target iron shield have already been removed. This work is carried out by a specialized firm under RP Group supervision. The data-loggers and the NORSK computer used to collect and store monitor readings from environmental stations and installed instruments in SPS and PS experimental areas have been decommissioned. Changeover to the microprocessor-based system ARCON (ARea CONtroller), already used at LEP, is being completed. Each ARCON handles information from up to 64 monitors and provides alarm signals for triggering visual and acoustic warning devices. The ARCONs are connected to the accelerator control and data transmission system (Token Ring). Long term storage of the hourly readings is ensured via a connection to an ORACLE data base. Jean-Pierre Munich, from CEA Institut de Protection et Surete Nucleaire (Fontenay-aux-Roses, Paris), has joined the Radiation Protection Group for one year. He will participate in calculations for the LHC project and in writing an LHC Environmental Impact Report. F. Carminati and K. Lassila (CERN Computing and Networks Division) have provided an interface between GEANT (a simulation code widely used in high-energy physics experiments) and the hadronic generator of FLUKA, a transport code developed by a collaboration CERN-Leipzig University-Helsinki University of Technology-INFN Milan (Report CERN CN/91/13 "Hadronic Cascade Simulation in GEANT", by K. Lassila). NEWS FROM CEBAF (Robert May ) ========================================================================= The Virginia Chapter of the AAPM (American Association of Physicists in Medicine) will hold a spring meeting at CEBAF on May 1st. The contact person is Coleman Rosen, President Elect, Va. Chapter (703- 698-3056). The meeting will include business sessions and a CEBAF tour. A dialog has been started with the AAPM on some type of relationship with the Accelerator Section of the HPS. Updates will follow. CEBAF has an opening for a Radiation Safety Technician. Contact Bob May at 804-249-7632 for information. NEWS FROM CYRIC, Tohoku Univ./Japan (Takashi Nakamura) ========================================================================= We have organized a collaboration for accelerator shielding experiments, which consists of seven groups belonging to different universities and national institutes. We have made plans for neutron-shielding and cross-section experiments in the AVF cyclotron (K=110) at the TIARA (Takasaki Ion Accelerator for Advanced Radiation Application) facility, Japan Atomic Research Institute. We have set up a unique monoenergetic neutron beam line for shielding and cross-section experiments. Monoenergetic neutrons in the energy range of 20 - 90 MeV can be obtainedd by the Li-7(p,n) reaction. The following experiments will start from April: 1) measurement of neutron and secondary photon penetration through matter, 2) measurement of response functions of fast neutron detectors, 3) measurement of neutron activation cross section, 4) measurement of neutron duct streaming, 5) measurement of neutron total and double differential scattering cross section, 6) measurement of photon and charged particle production cross section. NEWS FROM DESY (Herbert Dinter ) ======================================================================== HERA started operating during the last few weeks in 1991. For the firs time, electron and proton beams were successfully brought to collision, and luminosity was measured. Beam energies were 26 GeV for electrons (this is the design value) and 480 GeV for protons (design value is 820 GeV). The lifetime for both beams amounted to several hours. The intensities were still low. Only one bunch per each particle type circulated instead of the designed 210. Radiation protection problems were not expected (and did not arise) because of the low beam intensities and the complete shielding within the experimental halls. Both detectors (ZEUS and H1) were still in parking positions for installation and test runs with cosmic rays. Meanwhile, shut down is going on and the detectors are being moved into beam position. HERA runs are scheduled to begin again in April. With the beginning of 1992 the former Institute for High Energy Physics (IFH) at Zeuthen (former GDR) has become part of DESY. Physicists of this institute are involved in several collaborations such as L3 at CERN, H1 at DESY and in a neutrino experiment in the Lake Baikal. NEWS FROM ITALY (Alessandro Rindi ) ========================================================================= INFN AT FRASCATI (ITALY) The decommissioning of the linac and ADONE facility in Frascati (Italy) will start in March 1992. The entire facility includes a 300 MeV electron and positron linac, a 1.5 GeV crossing-beam storage ring (ADONE) and a facility for nuclear physics experiments (LEALE). First, the LEALE facility will be dismounted. By the end of 1992 the storage ring ADONE will be shut down. Following the decommissioning, a new facility will be built. This will be a high luminosity crossing-beam storage ring, DAPHNE (Double Annular PHI factory for Nice Experiments), where electrons and positrons of 510 MeV will be stored for the KLOE (K LOng Experiment) . experiment. A report on the decommissioning problems is in print. Following is a list of reports published by the Health Physics group. Copies can be requested from AESPOSITO@IRMLNF or AESPOSITO@LNF.INFN.IT P.Cristensen, A. Esposito, C. Nuccetelli, M. Pelliccioni, M. Prokic. ENERGY RESPONSE OF GRAPHITE MIXED MAGNESIUM BORATE TLD TO LOW ENERGY X-RAYS. APPLIED RADIATION AND ISOTOPES vol. 42, n. 11, pp 1037- 1038, 1991. C. Bacci, P. Bernardini, C. Furetta, B. Rispoli, C. Sanipoli, A. Scacco, P. Carafa, A. Carandini, A. Esposito. THERMOLUMINESCENCE DATING OF ARCHEOLOGIC ANCIENT ROMAN POTTERIES Rend. Fis. Acc. Lincei, s.9, 2:00-00 (1991) A. Esposito, M. Pelliccioni, C. Manfredotti, C. Ongaro and A.Zanini. A moderator-type dose equivalent monitor for environmental neutron dosimetry. Seventh Symposium on "Neutron dosimetry" Berlin, 14-18 October 1991 C. Birattari, A. Esposito, A. Ferrari, M. Pelliccioni and M. Silari A NEUTRON SURVEY-METER WITH SENSITIVITY EXTENDED UP TO 400 MeV Seventh Symposium on "Neutron dosimetry" Berlin, 14-18 October 1991 E. D'Aurizio, F. Desiato, A. Esposito, A.Ferrari, M. Pelliccioni VALUTAZIONI DOSIMETRICHE RELATIVE ALL'ATTIVAZIONE DELL'ARIA DURANTE IL FUNZIONAMENTO DELL'ACCELERATORE LISA LNF-91/081 (IR) 20 Novembre 1991 NEWS FROM KEK (Hideo Hirayama ) ========================================================================= All KEK Accelerators are now in operation after the winter shutdown. Operation of the new K-6 beamline at the north counter hall of Proton Synchrotron started from February 15. KEK has a plan to construct a high-intensity proton linac operating up to 10 MeV (maximum average current is around 3 mA). We want the neutron production data from thick targets of various materials due to protons around 10 MeV and information about the activation in air and cooling water at such a facility. Here is a list of reports published by members of the Radiation Safety Control Center in the fields of radiation shielding, radiochemistry and others. Interested individuals may request copies from Hideo Hirayama. Radiation shielding: Y.Harima,S.Tanaka,Y.Sakamoto and H.Hirayama,"Development of New Gamma- Ray Buildup Factor and Application to Shielding Calculation", J. Nucl. Sci. Technol. 28, 74-84 (1991) T.Nakamura and H.Hirayama,"Present Status and Future Subjects of High Energy Accelerator Bulk-Shielding Study" (in Japanese), J. Atomic Energy Society of Japan, 33, 539-548 (1991) M.Sakano,H.Hirayama and S.Ban,"Calculation of Dose Equivalents due to Stray Radiation from a High Energy Electron Beam in a Forward Direction" Radia. Prot. Dosim. 37, 165-173 (1991) Y.Namito and K.Ueki, "Gamma-Ray Transport Calculation Including Brems- strahlung by Monte Carlo Code MORSE", J. Nucl. Sci. Technol. 28, 695- 706 (1991) edited by H.Hirayama,Y.Namito and S.Ban,"Proceedings of the First EGS4 User's meeting in Japan", (in English with Abstract written in English) KEK Proceeding 91-14, December 1991 Radiochemistry and others: M.Noguchi et al.,"Production Cross Sections of Tritium in High Energy Nuclear Reactions with 12 GeV Protons", Appl. Radiat. Isot. 42, 577 (1991) M.Sakai et al.,"330-keV electron line in e+ +Th interactions", Phys. Rev. C 44, 944 (1991) T.Suzuki,Y.Oki,M.Numajiri,K.Kondo and Y. Ito,"Positron Annihilation in Irradiated and Non-irradiated Polyethylenes", KEK Preprint 91-87 (to be published in J. of Plym. Sci:Polym. Phys.) T.Suzuki,Y.Oki,M,Numajiri,K.Kondo,S.Fujita and Y.Ito,"Positron Annihilation in Epoxy Resins", KEK Preprint 91-112 (Presented at Int. Conf. on Psitron Annihilation, Szombathely, Hangary, 1991) T.Suzuki,Y.Oki,M.Numajiri,T.Miura,K.Kondo,Y.Tanabe,M,Ishiyama and Y.Ito "Radiation Effects on Polyethylene", KEK Preprint 91-114 (Presented at Int. Conf. on Evaluation in Beam Application, Takasaki, Japan, 1991 Y.Oki,K.Kondo,T.Suzuki,M.Numajiri,T.Miura,S.Doi and T.Ohnishi, "Radiation Effects on Polyaniline", KEK Preprint 91-118 (Presented at Int. Conf. on Evolution in Beam Application, Takasaki, Japan, 1991 NEWS FROM TRIUMF (Lutz Moritz ) ========================================================================= Everyone will by now have received their advance program for the IRPA8 Congress to be held in Montreal May 17-22, 1992. Probably not everyone knows that there was a rivalry between Vancouver and Montreal to host this congress. The host city was picked at a Board of Directors' meeting of the Canadian Radiation Protection Association and the vote was so close that the final decision was made by tossing a coin. But you don't have to miss out on visiting beautiful British Columbia this year because IRPA and CRPA are sponsoring the 2nd International Workshop on Non-ionising Radiation to be held just prior to the IRPA Congress here in Vancouver May 10-14, 1992. The Workshop will be held at the University of British Columbia and accomodation is available at the student residences (i.e. it's very reasonably priced.) Anyone who has not received their brochure for this workshop can get more information from: 2nd International INR Workshop Occupational Health and Safety University of British Columbia Suite 50 - 2075 Wesbrook Mall Vancouver, B.C. Canada V6T 1Z1 Telephone: 604-822-2029 FAX: 604-822-6650 Anyone interested in accelerators will get a personal tour of TRIUMF thrown in absolutely free (!) and if you are a sailor and the weather is reasonable I will take you for an afternoon of sailing on beautiful English Bay (except for Graham Stevenson who gets to climb to the top of Black Mountain at 8:30 the morning after he arrives!) ICRP/ICRU JOINT TASK GROUP (Ralph Thomas ) ========================================================================= At its meeting in Vienna, Austria last August, the International Commission on Radiological Protection (ICRP) approved the establishment of a Joint Task Group with its sister organization, the International Commission on Radiation Units and Measurements (ICRU). Ralph Thomas, Deputy Head, Hazards Control Department, LLNL, was selected to serve as chairman of the Task Group. The purpose of the Task Group is to prepare data of value in radiological protection against external radiation. It is intended that the report will be of particular value to dosimetrists involved in quantifying radiation fields and personnel exposures. The work is timely because both ICRP and ICRU have made substantial modifications to their advice during the past five years: for example, the new recommendations of the ICRP were issued as Publication 60 in November 1990. The report of the Task Group is intended to interpret and clarify these new recommendations to assist the working health physicist in his/her routine duties. Members serving on this international group include Dr. J. L. Chartier (Fontenay aux Roses, France); Dr. M. J. Clark (National Radiological Protection Board, United Kingdom); Prof. G. Dieze (Director, Physikalisch Technische Bundesanstalt, Germany); Dr. G. Drexler (Institut fur Strahlenschutz, Germany) and Dr. H. Menzel (Commission of the European Communities). The Task Group held its first meeting at the Headquarters of the National Radiological Protection Board of the United Kingdom near Oxford last week. Thomas reports that the meeting was successful and that a program for future work was agreed upon. It is the intention of the Task Group to prepare a final draft in two years. REVISION OF NCRP 51 ( Ralph Thomas ) ========================================================================= NCRP Report 51 entitled "Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities" has served the acceleratior community well for the past 15 years but much has happened since it first saw the light of day. About three years ago an NCRP Committee began to consider revising the report in the light of recent developments in radiological protection at accelerators. Members of this group were drawn from a wide variety of accelerator facilities so as to bring a broad perspective to this task. They are: W.R.Casey Brookhaven National Laboratory J.D.Cossairt Fermi National Accelerator Laboratory K.O'Brien North Arizona State Universit D.R.Perry (advisor) Rutherford Appleton Laboratory N.Rohrig EG&G Idaho Corporation. L.A.Slaback NIST. J.A.Spahn. NCRP. G.B.Stapleton. SSC (formerly of CEBAF) W.P.Swanson (deceased) Lawrence Berkley Laboratory . R.H.Thomas. LLNL, University of California. A final draft report will be ready late this summer for Council review. The report will have seven chapters and many appendices. Chapter headings are: Introduction; Particle Accelerators and Accelerator Facilities; Sources of Ionizing Radiation from Accelerators; Radiation Shielding; Dosimetry; Environmental Aspects and Operational Radiological Safety Program. If you have particular issues that you feel should be included in e this report, please contact the Committee Chairman, Ralph Thomas, LLNL, Tel. (510) 294 5154. CALL FOR PAPERS (Wes Dunn ) ======================================================================== It appears that Jon Sharp and I will be chairing a session on Radiation Safety/Dosimetry at the "Twelfth International Conference on the Application of Accelerators in Research and Industry" at the University of North Texas. The meeting runs from Nov 2-5, 1992 in Denton, Texas (near Dallas). While we are looking for papers that deal with any aspect of accelerator health physics, we are particularly interested in the problems of new and/or upgraded accelerator facilities and those dealing with PET and other production facilities (ie, dealing with both the accelerator and the product). Those attending are generally University accelerator-physics people who do not always have good grounding in Health Physics. If you have any interest (or know of someone who might be interested), please contact either Jon or me at (512) 834-6688 for more information. (Wes Dunn is from the Texas Bureau of Radiation Control) QUESTIONS? QUESTIONS? QUESTIONS? ========================================================================= Request for operating experience with SF6 leak rates ----------------------------------------------------------------------- (Jeff leavey ) ------------------------------------------------------------------------ I have a 200 MeV linac here at IBM as part of an X-ray lithography development facility and a question has come up concerning sulfur hexafluoride (SF6) gas leakage: What is an acceptable leak rate for SF6 from waveguides and associated equipment (liters/day, pounds/month, etc.)? I need to know if some leakage (and how much) is considered normal, or if the majority of facilities have no detectable leakage under normal operating conditions. Any and all help will be greatly appreciated. I'll be happy to post a summary for the benefit of all. Please call me at 914-892-3157 and leave a message or send mail to: leavey@watson.ibm.com. Accelerator Accident In Maryland - December 1991. ----------------------------------------------------------------------- (Chuck Salsbury ) ----------------------------------------------------------------------- There was an accelerator accident in Maryland about the end of December. Apparently "an operator" bypassed some interlocks and walked into a dynamatron (3MV) with the current turned down but the voltage still up. He stuck his hands and face in front of the machine. The dose is presently unknown. If anyone has any information regarding this accident, please send the information by E-Mail to me, with a copy to IPE@SLACVM. Questions For Health Physicists Working At Synchrotron Radiation ------------------------------------------------------------------------- Facilities (Alessandro Rindi ) ------------------------------------------------------------------------- Did you ever consider the possibility of accidentally extracting the stored beam or part of it through a synchrotron radiation beam line? What will happen if one or more magnets of the storage ring fail or if the rf trips? Is there a chance that part of the stored beam channels into an experimental line? Did you ever make any experiment or theoretical study of the problem? Can this, possibly, be excluded from the project of the safety at a SR facility? If you have any report or draft study on this topic, please send it to me. If you think the problem should be further investigated, we could organize a meeting of interested people. Please, address your views to: Alessandro Rindi Sincrotrone Trieste Padriciano 99 34012 TRIESTE (Italy) E-mail RINDI@ELETTRA.TRIESTE.IT Please send a copy to IPE@SLACVM as well. ANSWERS! ANSWERS! ANSWERS! ========================================================================= In-Reply-To Rindi (Nisy Ipe ) ----------------------------------------------------------------------- Your questions are very thought-provoking. These same questions have been raised here, at the Stanford Synchrotron Radiation Laboratory (SSRL), several years ago. The accelerator physicists tell us that since it takes some finite time (1 sec) for the magnetic fields to decay, it is unlikely that the stored beam will go directly down the synchrotron beamlines. Even if one assumed that the magnetic fields in the bend magnets collapsed infintely fast, if the magnet fails, the beam will spiral outwards and impinge on the smallest aperture (like masks), and will be lost in milliseconds. All the bend magnets are in series. If the rf trips, the stored beam will spiral inwards and be lost in a similar manner. Thus it is highly unlikely that the stored beam will be transported down the synchrotron beamlines. However, sometimes kicker magnets are turned on while there is a stored beam, for machine physics studies. Then if the timing and strength are optimum, one may under some scenario be able to transport the stored beam dowm the synchrotron line. The probability is extremely small, but not zero. I would be very interested to find out what others have to say. Closing Thoughts ======================================================================== " A system consists of components. Any company, any industry, consists of components that are different activities. All the components of the system must contribute to the system, not exist for their individual gains." W. Edwards Deming