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) ====================================================================== May/June 1995 Vol. 4, #3 ====================================================================== OFFICERS ====================================================================== President: Nisy Ipe, SLAC President-Elect: Bob May, CEBAF Past President: Geoff Stapleton, CEBAF Secretary: Steve Musolino, BNL Treasurer: Joe McDonald, PNL Newsletter Editor: Lutz Moritz, TRIUMF Directors: Lorraine Day (1997) Don Cossairt (1997),FNAL De Vaughn Nelson (1996) Paula Trinoskey (1996),LLNL Jerry Miller (1995), LAMPF Carter Ficklen (1995), CEBAF >From the Editor Lutz Moritz ====================================================================== As this is the final Newsletter before I hand over the baton to my successor, I would like to thank some of the people that have helped to make the task of producing the Newsletter such an enjoyable experience. Bob May for helping me set up and get started, Nisy Ipe for her occasional prodding and good advice, and Vashek Vylet for helping with the twisting of arms to gather contributions and the mechanics of distribution. Thanks also to all those who have contributed their time to write the interesting and thoughtful articles or reports on their activities. In this issue are two requests to which you are asked to respond promptly. One is from Geoff Stapleton who is asking for an expression of support to have Bob May selected as a delegate to the IRPA96 congress. Please respond promptly directly to Geoff. The second request is from Nisy Ipe for an expression of interest in the proposal for an HPS mid-year symposium on "The Health Physics of Radiation Producing Machines". In this case you are asked to complete the questionnaire and return it promptly to Nisy. The probability of having such a symposium will be greatly enhanced if we receive a large number of positive responses. From personal experience I can tell you that the last such symposium held ten years ago in Reno was one of the most interesting and diverse meetings I have ever attended. >From the President Nisy Ipe ====================================================================== Dear Friends: It has been a pleasure and a privilege for me to serve you all as President of the Accelerator Section. As I come to the end of my term I am reminded of Wade Patterson and Ralph Thomas, without whose encouragement I would not have had this opportunity of leadership in the Section. About 4 years ago Wade drove 1 hour from Livermore to SLAC just to take me out to lunch. At that point I had no inkling about what was to happen. After a pleasant meal Wade indicated to me that he and Ralph wanted me to stand for the position of Secretary. Later Ralph called me and told me that if I couldn't beat the old boys network, the best thing to do would be to join them. Needless to say, they charmed me into standing for the position. I have enjoyed every moment of my responsibility then and now and would like to express my heartfelt gratitude to the two "old boys". THANK YOU WADE AND RALPH! I would also like to thank all the board members for their hard work and all of you for all your support. I wish Bob May all the very best as he takes on his role as President. I hope the Section will continue to have the international flavour that makes us really unique. In closing I would like to share my philosophy inspired by words from the Bible: "Whatever your hand finds to do, do it with your might". Geoff Stapleton (Past President) ====================================================================== Dear Accelerator Section Members, In view of the close ties of the Accelerator Section to the international radiation protection community, it seems to me that it would be extremely appropriate to have a representative of the Accelerator Section considered as a delegate at the IRPA congress in 1996. It would also be appropriate for our candidate to be the Accelerator Section President in Office in 1996. I know that many members have already given their support to other candidates but it is possible that there are some who have not so far committed themselves and I would strongly urge those to consider endorsing the candidature of Bob May, who is our current President Elect. Please let me know if you would be willing to sign a petition on behalf of Bob May to be a delegate at the 1996 IRPA congress. I would like a speedy reply as time is rather short. Yours, Geoff Stapleton (Past President) MEETINGS ====================================================================== The American Nuclear Society Radiation Protection & Shielding Division TOPICAL MEETING Cape Cod, Massachusetts SECOND CALL FOR PAPERS 1996 Radiation Protection and Shielding Division Topical Meeting: "Advancements and Applications in Radiation Protection and Shielding" April 21-25 1996, Sea Crest Resort, 350 Quaker Rd., N. Falmouth MA 02556 This is the official call for papers for the 1996 RPSD Topical Meeting. You are encouraged to submit 600-900 word summaries des- cribing significant advancements or innovative applications in the area of radiation protection and shielding. Please submit an original and two copies of the summary to the Technical Program Chair: Keith B. Spinney Yankee Atomic Electric Company 580 Main Street Bolton MA 01740-1398 Telephone:(508) 779-6711 X2039; Fax:(508) 779-6730; e-mail: spinney@yankee.com The deadline for submittal is August 16, 1995. Authors will be notified of selection on or about October 1, 1995. Full camera-ready papers will be due January 19, 1996 for inclusion in the proceedings which will be distributed at the meeting. Paper topics are being accepted for, but are not limited to, the following topics. Please indicate the applicable topic with the summary. Shielding Issues Reactor Cavity Gamma Dosimetry Accelerator Shielding Numerical Dosimetry Advanced Neutron Source Shielding Pressure Vessel Dosimetry Fusion Reactor Shielding Material Damage Correlations Point Kernel Techniques & Applications Radioactive Waste Issues Skyshine Analysis Low-Level Waste Packaging Space Reactor Shielding & Site Design Issues LMFBR Shielding High-Level Waste Packaging Transport Theory Analysis & Site Design Issues Advancements in Discrete Ordinates Interim Spent Fuel Storage Applications of Discrete Ordinates & Transport Casks Advancements in Monte Carlo Methods Site Characterization Applications of Monte Carlo Methods & Decommissioning Comparison of D.O. & M.C. Methods Health Physics/Medical Issues Benchmark Experiments & Integral ALARA Program Developments Tests Dose Reconstruction Cross Section Libraries & Data Environmental Monitoring Uncertainties for Public Perception Radiation Streaming Implications of 10CFR20 Computer Applications on Worker Perceptions Graphical User Interfaces Computational Methods Non-Traditional Geometries for Medical Applications for Transport Applications Radiation Epidemiology PC Applications/Computer Visualization & Health Effects Radiation Dosimetry Radiation Protection Standards & Material Damage for Medical Applications Radiation Detection & Measurement Component Activation Analysis Digital Dosimetry Workshops/tutorials will be held on MCNP, DORT/TORT and FLUKA. NOTE: The HPS Society and the Accelerator Section are co-sponsors of this conference. NEWS FROM IARPENL CORRESPONDENTS ====================================================================== News from CEBAF Bob May ---------------------------------------------------------------------- !!! 4 GeV Design Energy Achieved at CEBAF !!! Early on May 9, 1995 an electron beam in the CEBAF accelerator reached design energy of 4 GeV in a design-maximum five full passes through the recirculating machine's pair of linked superconducting linacs. The low-current beam was pulsed. Commissioning progress is on track for physics research with 4 GeV CW beam at the current requested by experimenters. As reported earlier, initial physics measurements have been made in Hall C, and first physics is planned for Halls A and B during 1996. Bob May News from SLAC Vashek Vylet ---------------------------------------------------------------------- 1. JOB OPENING As of June 1, 1995, Nisy Ipe became Head of the Radiation Physics Department at SLAC, after the previous Department Head, Ken Kase, was promoted into his current position of Associate Director and Head of the ES&H Division. This creates a vacancy in the Radiation Physics staff advertised below: The Stanford Linear Accelerator Center (SLAC), a high energy physics research facility, has an immediate opportunity for a Health Physicist / Radiation Physicist The successful candidate will assume responsibility for shielding design, radiological considerations and operational aspects of the assigned facility. Work closely with machine physicists and beamline designers. Write Beam Authorisation Sheets and assist with the design / development of personal protection systems and beam containment devices, perform shielding, activation calculations and dosimetry, and provide general assistance to experimenters. Position requires a Physicist, Health Physicist, or Engineer. A Ph.D. with useful accelerator experience is preferred; MS with equivalent experience would be considered. Experience required includes accelerator shielding, radiation transport calculations, and neutron, photon, and charged particle dosimetry. Excellent communication skills and the willingness to work nights/weekends essential. Familiarity with computer systems, programming languages and instrumentation systems desirable. For immediate consideration, send resume, indicating Job #17497, to: SLAC, P.O. Box 4349, M/S 11, Stanford, CA 94309. Equal Opportunity employer through affirmative action. SLAC provides a smoke-free environment. 2. PROPOSED SYMPOSIUM - HEALTH PHYSICS OF RADIATION GENERATING MACHINES Some of you participated in a HPS mid-year topical symposium entitled "HEALTH PHYSICS OF RADIATION GENERATING MACHINES" held at Reno, Nevada. The Accelerator Section would like to make a proposal to the HPS to hold another similar symposium at the mid-year meeting of the HPS in San Jose, California. The Section has appointed Vashek Vylet to serve as the liaison between the local chapter of the Health Physics Society and the Accelerator Section to investigate the possibility of holding such a Symposium. Vashek hopes to submit a proposal to the Symposia Committee at the Annual HPS Meeting in Boston (July 1995). In order to help us with our proposal we need to identify the level of interest for such a symposium among members of the accelerator community. Would you take a few minutes to answer the following questionnaire? <<<<< Cut here and edit: >>>>> ====================================================================== Questionnaire: ---------------------------------------------------------------------- 1) Name: Address: Telephone No.: Fax No.: E-mail address: Occupation: 2) Would you be interested in and willing to participate in a symposium on "The Health Physics of Radiation Producing Machines"? YES NO 3) List the topics that would be of most interested to you: 4) Would you consider presenting one or more papers at the symposium? YES NO If YES, state proposed topic(s) of the paper(s): 5) Would you be willing to serve on a technical program committee? YES NO 6) Would you be willing to teach a short course/tutorial? YES NO If YES, identify subject matter: Please return your response to Nisy Ipe by July 15, 1995. (Nisy Ipe ) News from TRIUMF Lutz Moritz ---------------------------------------------------------------------- After months of waiting TRIUMF finally received a budget commitment from the Canadian government which stabilizes the funding of the laboratory for a period of five years. The budget allows for continuing operation of the present meson and nucleon programs, the construction of an accelerated radioactive beam facility (ISAC) and for a contribution in the form of manpower and equipment to the LHC. The government of the province of British Columbia has also promised $CAD 10 million for the construction of the buildings to house the new facilities. Nevertheless there is likely to be some 'restructuring' (the current euphemism for staff reduction) at the laboratory. The first to suffer is the visitor program which has been, at least temporarily, cancelled. The proton therapy facility at TRIUMF which is intended to treat ocular melanomas using low energy (70 MeV) protons extracted from the 500 MeV cyclotron finally successfully passed all safety reviews and has received a licence to commence operation. The first patient will probably be treated within the next month. GUEST ARTICLE ====================================================================== A Necessary Tool for Accelerator Radiation Safety (informal note prepared by Tony Gabriel and Geoff Stapleton after a presentation given by Pavel Degtyarenko on May 19, 1995 at CEBAF) Introduction In order to make cost-effective provisions for the radiation safety of electron accelerator facilities, such as the design of shielding, it is necessary to determine the angular energy yields of hadrons (neutrons, protons, pions) resulting from electron beam interactions (beam loss). It is common practice to make use of empirical methods which are mainly effective for simple thick slab shielding cases. For the design of such features as complex access labyrinths and ducts, where know- ledge of a full neutron energy spectrum is necessary, recourse has been made to fluence and dose measurements in simple cases which must then be applied to real situations. All these approximations have meant that designs are essentially not optimal and, as a consequence, include substantial conservatism with inevitable increased cost. There is, therefore, a need for a photo- and electro-nuclear inter- action model for the generation of angular energy hadron spectra that can be coupled to existing powerful transport codes such as EGS and GEANT. These codes utilize well established models for simulating the e/g shower in addition to comprehensive techniques for modeling complex geometries and transporting the photo- and electro-produced hadrons. In addition to radiation safety, the availability of a hadron pro- duction generators of great importance for the design of experimental equipment such as detectors and spectrometers used in nuclear and particle physics research. What Exists at Present At the low end of the photon energy spectrum, characterized by the giant dipole resonance region, cross sections are reasonably well known for given production channels but there appears to be limited quantitative information on the energy spectra of the hadrons produced in the reaction. At intermediate energies (<0.5 GeV), there are few event generators. The code PICA has been available since the early 70's; this code, written by Gabriel, utilizes the quasi deuteron model including single pion production, and reproduces the angular energy doubly differential cross sections reasonably well when compared with limited existing experimental data (Gabriel 1969). For electro- production the Lightbody code is currently available but its utility is limited to thin experimental type targets (Lightbody 1988). At high energies (>10 GeV) well above the pion production region, groups at SLAC and CERN have implemented the vector meson dominance model for the nuclear reaction to provide an event generator which couples with the e/g shower code EGS and the hadronic cascade code FLUKA (Ranft 1987). There is, therefore, a gap in providing an event generator spanning all the electron beam energies, up to several GeV, for both photo- and electro-hadron production and also one that will seamlessly inter- face with all the available hadron transport codes. Nuclear Fragmentation Model Utilized by DINREG Historically the origin of this model begins with the original work by M.Kossov (ITEP, Moscow), where experimentally observed regularities of nuclear multifragmentation at high energies were understood within the concept of thermodynamic quark source in the excited nucleus and the rules of hadronization (Kossov 1984). The model was implemented in the form of a computer program - exclusive event generator of nuclear multifragmentation which generates secondary neutrons, protons, pions and nuclear fragments fully conserving energy, momentum, and charge in the reaction (Degtyarenko 1992). Current version (unpublished) was created by M.Kossov in 1992 (Kossov 1993) and developed, debugged and applied to photonuclear reactions by P.Degtyarenko in 1993-1995. The event generator reproduces particle multiplicities and spectra in reactions with multihadron production at nuclear excitations 0.2 GeV and more. Empirically, it was found possible to extend its applic- ability to the region of lower nuclear excitations. Present Status of DINREG as a Radiation Protection Tool DINREG is currently being developed into a practical tool by Degtyarenko, who is at present on a 6 month attachment to CEBAF from the University of Massachusetts. The code is being produced as a stand-alone event generator package and is also being implemented to run with the suite of codes known as GEANT which provides a framework for detailed Monte-Carlo modeling of all major physics processes in complicated realistic geometries. So far the results for electro- and photo-production at all electron energies from the GDR region up to about 10 GeV agree reasonably well with available experimental data and are extremely promising. In order to preserve, improve and ruggedize this code and to make a stable version available to the wider accelerator radiation protection community the work on it is continued. References Degtyarenko 1992 P.V.Degtyarenko, M.V.Kossov, "Monte - Carlo program for nuclear fragmentation", Preprint ITEP-11-92, Moscow (1992). Gabriel 1969 T.A.Gabriel and R.G.Alsmiller Jr., "Photonucleon and photo- pion production from 400 MeV electrons in thick copper targets", Nucl. Phys. B14, 303, (1969). Kossov 1984 M.V.Kossov, L.M.Voronina, "Thermodynamic quark-parton model of multiple hadron production on nuclei", Preprint ITEP-165, Moscow (1984). Kossov 1993 M.Kossov, "Monte Carlo Generator for nuclear fragmentation induced by pion capture", MC93 International Conference on Monte Carlo Simulation in High Energy and Nuclear Physics, Tallahassee, Florida, USA, 22-26 February 1993, p. 190 Lightbody 1988 J.W.Lightbody, Jr. and J.S.O'Connell, "Modeling single arm electron scattering and nucleon production from nuclei by GeV electrons",Computers in Physics, May-June 1988, p.57. Ranft 1987 J.Ranft and W.R.Nelson, "Hadron cascades induced by electron and photon beams in the GeV range", Nucl.Instrum. & Methods, A257, 177 (1987). CLOSING THOUGHTS ====================================================================== One ought, every day at least, to hear a little song, read a good poem, see a fine picture, and, if it were possible, to speak a few reasonable words. -- Johann Wolfgang von Goethe (Wilhelm Meisters Lehrjahre)