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) ====================================================================== January/February 1995 Vol. 4, #1 ====================================================================== 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 ====================================================================== A short Newsletter this time with not many contributions from the international correspondents. However there are some letters from places we don't normally hear from and I think it would be interesting to have more of these. There are also some important announcements regarding section business, upcoming meetings and the DOE laboratories' training program. As the number of subscribers to the Newsletter becomes larger, one of the most difficult tasks is to keep the e-mail distribution list up-to-date. People appear to change their e-mail address much more casually and frequently than their postal address. I would therefore urge you to remember to let us know when your address changes, other- wise your poor editors have to spend a lot of time trying to 'finger' you and if that does not work you will of course no longer receive the Newsletter. To see if your address is up-to-date you simply send the message 'QUERY IARPE-L' to . This will return the whole mailing list and you can check whether you are correctly listed. Section Business Geoff Stapleton ====================================================================== Minutes of a Meeting (informal) of the Accelerator Section (Held during the HPS mid year meeting at Charleston SC) Tuesday January 31, 1995 at 5.00 pm Members Present: David Boehnlein, Ron Buchanan, Bob Casey, Lorraine Day, Carter Ficklen, Ken Kase, Frank Masse, Wade Patterson, Geoff Stapleton (acting chairman), Paula Trinoskey, Vashek Vylet, Keith Welch. Geoff Stapleton deputized for Bob May who was to chair the meeting on behalf of the President but was prevented from attending at the last moment. Bob May and Nisy Ipe sent their apologies for absence. Nisy also provided some notes to be included in the tentative agenda. The agenda was agreed by those present at the meeting. 1. Accelerator Section Night - Out at the Boston HPS meeting. The chairman was requested to contact Steve Musolino (Section Secretary) and convey the views of the meeting on this subject. It was recognized that last years event, the San Francisco night out, was a special event to mark the importance of the venue in the history of accelerators and that it should not set a precedent for other meetings. If a technical visit or tour to a local accelerator laboratory could be organized in conjunction with the HPS local organizing committee, this need not be elaborate or costly; however, if this could not be arranged then a social gathering at a local restaurant would be an agreeable alternative. It was viewed as quite acceptable to be "low key". Arrangements for the latter, such as numbers, could be finalized during the meeting. Frank Masse agreed to help with advice on selecting a suitable restaurant if that turned out to be the desired event. 2. Abstracts of Papers The Chairman reminded those present that the deadline for abstracts to the Boston meeting was February 3, 1995 and encouraged anyone who had any interesting work to report to hurry up with the submission of an abstract. Bob May, the Section's President Elect was the technical session organizer. The chairman informed the meeting that Dr. Alfred Smith of the Massachusetts General Hospital would be the keynote invited speaker for the Accelerator Section technical session and that another speaker would be invited to speak but that the final program would have to wait the receipt of all abstracts. 3. Accelerator Laboratory Contractors Committee The Chairman informed the meeting that the President, Nisy Ipe would be 'phoning round the accelerator laboratories with the view to setting up a committee to oversee and commission "industry codes of practice" on radiation protection topics. This committee would be expected to have an additional responsibility of making recom- mendations for additions and improvements to the DOE Accelerator Order guidance notes. 4. Logo/letterhead competition The meeting considered the specimens offered and chose one offerin as the winner. Because it incorporated part of the HPS logo the chairman was asked to obtain the permission of the HPS for its use. The name of the winner will be disclosed in due course and the Section would like to thank all those who entered the competition. 5. Future Activities of Accelerator Section Ken Kase and David Boehnlein informed the meeting that they were continuing their exploration of setting up a dedicated calibration source for the accelerator radiation protection community. The problem was in generating funding for a facility of which only part would be intended for radiation studies. It was agreed that future action to be taken on this matter, e.g., writing letters to accelerator laboratory directors should be left to the discretion of the members of the committee being set up by Nisy Ipe. Ken Kase informed the meeting that the IRPA congress in Vienna in 1996 would have an accelerator session and members of the HPS were encouraged to attend. Ken also said that some funding would be available from the HPS for people who wished to attend but this required the person to enlist the support of a number of members of the HPS. If anyone was interested in seeking HPS support, they should contact the HPS secretariat for details. 6. Any Other Business The suggestion was raised about the possibility of having a topical meeting on accelerator radiation protection. The last such meeting was in Reno in 1987 and if one added on the necessary lead time of 2 to 3 years to organize such an event it would be more than 10 years between meetings. The suggestion met with general approval among those present. Ken Kase and Vashek Vylet mentioned that the 1997 spring meeting was scheduled for San Jose and the topic had not yet been decided. It was suggest that Vashek carry the suggestion for the topic of Accelerator Health Physics to the Symposium Committee for their consideration. David Boehnlein raised the topic of training and informed the meeting about the problems of developing a lesson plan and training guide for accelerators. A number of people from different facilities had formed an ad hoc committee chaired by Jim Allan (SLAC) to produce this material. The material had been sent to Westinghouse (Hanford) by the committee so that the material could be distributed to users for comment. However, in the out-turn it was not clear that the material was sent to the appropriate users and that proper instructions were given to enable the material to be adequately reviewed. Dave Boehnlein agreed to write a letter to be sent to Lutz Moritz for inclusion in the current IARP newsletter explaining about what to do with the package of training material received and in the case of any who have not received the material, what they should do to get it. Paula Trinoskey raised the question of the need for some "standard" materials for inclusion in the DOE standardized Radcon Technician training on the subject of accelerators. Presently there are none. This portion of "core material" would be required only for tech- nologists working at accelerator facilities. Comments were in general agreement that any such material would be helpful, and that it would seem to fit best in the "site academics" portion of the training package. There being no other business the meeting was adjourned. ANNOUNCEMENT! Wade Patterson ====================================================================== The Nominating Committee, Charles Flood, Wade Patterson and Ralph Thomas, is pleased to announce that the following persons have accepted our offer to be nominated for: a. President Elect, for 1 year, Lutz Moritz, TRIUMF b. NewsLetter Editor, for 1 year, Vaclav Vylet, SLAC c. Treasurer, for 2 years, Carter Ficklen, CEBAF d. Director (2), for 3 years, Jeff Leavey, IBM, Tracy Tipping, Kansas St. Univ. We invite all others who wish to be nominated for an office to make their wishes known to Wade Patterson, Chairman. We plan to ask for nominations from the floor at our next General Meeting as well. If none are forthcoming we will move that the Section elect those named above by acclamation. If there are other nominees, we will have a secret ballot. TRAINING Dave Boehnlein ====================================================================== I'd like to drop a note to my colleagues in the DOE accelerator community. As you know, the DOE RadCon Manual requires us to augment our radiation safety training with materials specific to accelerators and the radiological hazards which are unique to them. To address the requirement, a working group was formed from members of several DOE accelerator labs and chaired by Jim Allan (SLAC). When we finished a draft of our lesson plan and study guide, we passed it on to the Standardized Training Oversight Group (STOG) at Westinghouse Hanford. It was our assumption that they would distribute the draft materials to all DOE accelerator facilities for review and comment, collect comments, and pass them back to the working group so that we could produce an appropriate revision. The purpose of the final product would be to give the training development people at each accelerator facility a set of core materials to work with, from which they would select those portions that are relevant to their own facility to use in the training at their site. It was certainly not intended that every facility should train its workers in the details of every accelerator in the DOE complex! Unfortunately, when STOG sent out the materials, they do not seem to have included an explanation of this intent. It may also be that not all accelerator facilities have been issued copies for review. We discussed this matter at the section meeting in Charleston and I agreed to send out a note to let people know what is going on. Jim has contacted Pete Seilhymer at STOG to clarify the matter, and the deadline for comments has been extended for two weeks. STOG's phone number is (509) 373-1208; FAX (509) 376-1045. The contact person is Pete Sielhymer. NEWS FROM IARPENL CORRESPONDENTS ====================================================================== News from CEBAF Bob May ---------------------------------------------------------------------- Three-Pass Beam and First Physics at CEBAF During December, third-pass commissioning took place as scheduled at the Continuous Electron Beam Accelerator Facility, Newport News, Virginia. In the process, CEBAF's five-pass, 4 GeV recirculating machine for the first time delivered beam for a physics measurement. Measurements began within hours of the cw beam arriving on target, both at 750 MeV and 2.1 GeV. A sieve collimator was used to check the optics and the data acquisition system of the Hall C High Momentum Spectrometer (HMS), which had been receiving low duty factor beam for checkout and debugging during earlier commissioning phases. Data were reproduced at the same kinematics as, and in agreement with, previous high-energy electron scattering data, but -- due to the CEBAF beam's "cw" nature and the HMS's large acceptance -- with better statistics in less running time. On December 17, starting from "dead stop" after having completed two passes previously, accelerator operators were able to use nominal settings to attain the third pass; within six hours, two passes were re-established and beam was sent through the previously untransited third. News from FERMILAB Dave Boehnlein ---------------------------------------------------------------------- Things are remaining more or less steady at Fermilab. We are continuing to operate the Tevatron in collider mode as the CDF and D0 experiments collect data in search of further evidence of the top quark and other new physics. Except for a one-month shutdown from mid-February to mid-March, we plan to run in collider mode until autumn, at which point we will begin to prepare for fixed-target physics experiments scheduled to begin in 1996. One of the most exciting of these is the KTeV (Kaons at the Tevatron) experiment, which will study rare K-meson (kaon) decays in an attempt to understand CP violation. CP violation is the breakdown of a natural symmetry which ordinarily indicates that when the parity of particles in a system are interchanged and the particles are replaced by their antiparticles, the overall system should look and behave the same. This rule is violated in the decays of some kaons. The goal of this experiment is to measure the ratio of CP violation parameters and, search for direct CP violation in the neutral kaon/anti-kaon system. The precision of these measurements will severely constrain the range of Standard Model predictions. The experiment makes use of a double-beam technique, whereby both K-long and K-short decays are studied simultaneously. For this effort a new KTeV facility is being constructed to take advantage of the Tevatron primary protons up to 5E12 per spill and its superior duty cycle. The KTeV spectrometer consists of a 60 meter vacuum decay space, electro- magnetic calorimetry, tracking and magnetic spectrometer, nearly hermetic photon vetoes, transition radiation detectors, and hadron and muon detectors. On the health physics front, I'm afraid that most of our resources are currently being expended on compliance with the requirements of the new federal regulation on Occupational Radiation Protection, 10 CFR 835. We anticipate that we will be in full compliance with the regulation by the deadline of January 1, 1996, but unfortunately our work on compliance will seriously decrease the time, manpower and funds that might otherwise be available for "real work" in health physics, including research in accelerator health physics. Following as closely as it does upon the heels of the DOE Radiological Control Manual and preceding only by months the new regulation on environ- mental protection, 10 CFR 834, it sometimes seems as if we are so busy keeping up with new rules and regulations that we are unable to do anything else. It is our fervent hope that the regulatory environment will be stabilized at last with the implementation of these CFRs. News from SLAC Vashek Vylet ---------------------------------------------------------------------- 1. NCRP REPORT PLANNED The National Council on Radiation Protection and Measurements has approved the formation of a Scientific Committee to write a report that will provide recommendations for the design of radiotherapy facilities. This report will cover accelerators in the energy range from 1 to 50 MeV and x-ray therapy units up to a few hundred keV. The report-writing effort is supported by the American Association of Physicists in Medicine and most of the meetings of the Scientific Committee will be held in conjunction with AAPM meetings. The Committee Chair is being selected and it is expected that the Committee will be functional by the time of the joint meeting of the HPS and AAPM in Boston in July. Ken Kase 2. 1997 MID-YEAR HPS MEETING The Symposia Committee, which is responsible for organizing the HPS mid-year meetings, is looking for suggestions of topics for the 1997 meeting in San Jose. During a brief gathering of the Accelerator Section members in Charleston, it was concluded that it might be appropriate and timely for our Section to propose the "Accelerators" topic. When I later discussed this issue with Glenn Sturchio, chairman of the Symp. Committee, he suggested to widen the topic to "Radiation Producing Devices" or something similar, in order to attract a wider audience. Please e-mail me your thoughts and sug- gestions on this issue at the address below so I can best represent our cause during the future deliberations of the Symposia Committee. Vashek Vylet News from TRIUMF Lutz Moritz ---------------------------------------------------------------------- These past few months we have been trying to get our proton therapy facility operational. This facility extracts approximately 5 nano- amperes of proton beam at 70 MeV from our 520 MeV cyclotron which routinely operates with beam current of the order of 150 microamperes. The 70 MeV beam is dispersed by passing it through a thin Pb foil and the proton Bragg peak is then spread out using a rotating wedge of plastic. The range of the protons can also be shifted using a brass wedge. The dispersed, spread-out beam is finally collimated with a patient-specific collimator and used to treat intra-ocular melanomas. The advantage is of course that by using protons one can limit the treatment volume and not significantly affect sensitive nearby struc- tures such as the optic nerve. The technology is not new and such treatment modes have been and continue to be used at number of facilities around the world. The perceived safety problem at TRIUMF is that the cyclotron is obviously capable of delivering a dose far in excess of what is needed for safe treatment and the situation has certain parallels with the infamous Therac-25. Only approximately 2% of the 5 nanoamperes of 70 MeV beam reaches the patient's eye. So one must assure that it is not possible to accidentally put 10 or even 150 microamperes into the treatment volume (or into any other part of the patient). Initial treatments will either run during polarized beam periods when the beam circulating in the cyclotron is restricted to less than a few micro- amperes by the physics of the polarized ion source or the high- intensity beam will be restricted by the 'pepper pot' (a plate with an array of fine holes) in the injection line. The Safety Review has focussed on examining the integrity and reliability of various interlocks and the quality assurance for the development of the control systems. Of special concern has been the interaction of the local proton therapy operators and the operators of the 520 MeV cyclotron. An external review committee met late last month and their report is expected shortly. FROM THE MEMBERSHIP ====================================================================== Pohang Light Source Heeseock Lee ---------------------------------------------------------------------- The initial commissioning of the Pohang Light Source (PLS) was completed last December following the successful commissioning of the 2 GeV linac last May. On October 26, 1994, the commissioning of the PLS achieved its goal of storing an electron beam of more than 100 mA at 2 GeV, and within less than two months, on December 24, 1994 300 mA were stored. The Pohang Accelerator Laboratory (PAL) held a dedication ceremony for the PLS project on December 7, 1994, which was attended by President Kim Young-sam and two Ministers. Now PAL's personnel are very exciting. PLS has scheduled user experiments from June 1995 through to the maintenance period during which there will be a bake-out of the storage ring vacuum chamber and replacement of several flexbend components. However all persons in the Radiation Safety Control Group received some high levels of radiation dose near the injection point of the storage ring at the beginning of the commissionning. This resulted from a poor injection efficiency among other things. We have few problems yet and will re-enforce the weak points in the shielding and improve the injection efficiency which will reduce the dose. If anyone has practical experience of radiation problems during commissioning of a storage ring, let me get a chance of sharing it. Any advice will be appreciated. Kernfysisch Versneller Instituut Hans Beijers ---------------------------------------------------------------------- One of my responsibilities concerns the radiation safety at the Kernfysisch Versneller Instituut, one of the two national laboratories in nuclear and atomic physics in The Netherlands. Right now we are in the process of commissioning AGOR, a K = 600 MeV superconducting cyclotron capable of accelerating both light (protons, deuterons) and heavier ions. The maximum proton energy is 200 MeV. The last few years I have been very busy with addressing the radiation safety aspects connected with operating this machine, i.e. writing a radiation safety report in order to get an operating license, radiation safety calculations for the cyclotron and experimental vaults, radiation safety interlock system etc. Because the KVI is a small laboratory I am the only person working on these matters. Also because we are the only lab in The Netherlands operating a big cyclotron there are not many colleagues around with whom I can discuss these matters. Therefore I am really glad to be able to have contact with other accelerator health physicists via the IARPE newsletter group. One of my interests is the use of Monte Carlo codes like FLUKA and LAHET for shielding calculations. Another project I am involved in is to use AGOR for proton therapy, particularly in measuring and calculating the dose distributions. CLOSING THOUGHTS ====================================================================== He who asks is a fool for five minutes, but he who does not ask remains a fool forever. -- Old Chinese saying