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) --------------------------------------------------------------------------- November/December 1997 Circulation: 198 Vol.6, #6 --------------------------------------------------------------------------- OFFICERS President: Vashek Vylet, SLAC President-Elect: Steve Musolino, BNL Past President: Lutz Moritz, TRIUMF Secretary: Scott Walker, LANL Treasurer: Gerry Fallon, MIT Newsletter Editor:Scott Schwahn, Jefferson Lab Directors: Jeff Leavey, IBM (1998) Tracy Tipping, KSU (1998) Wes M. Dunn, Texas Department of Health (1999) Henry Kahnhauser, BNL (1999) Bob May, Jefferson Lab (2000) Keith Welch, Jefferson Lab (2000) CONTENTS Officers From the Editor From the President News from correspondents: AGS CAMD CERN DESY Jefferson Lab LNF LNLS Texas Bureau of Radiation Control How to subscribe or update subscription Closing thought --------------------------------------------------------------------------- From the Editor Scott Schwahn --------------------------------------------------------------------------- I am hoping this newsletter will find each of you going into the holiday season joyful and optimistic about the upcoming year. This newsletter includes no feature article, as no one has "stepped to the plate" to provide one. I am interested in any and all opinions about whether or not you find the feature article to be a valuable part of this publication. At any rate, you will find updates on some facilities that I don't recall ever hearing from before, a well as some we haven't heard from in a while, and some ever-faithful contributors. We have facility updates from AGS, CAMD, CERN, DESY, Jefferson Lab, LNF, LNLS, and the Texas Bureau of Radiation Control. I am very pleased to have so many contributions from overseas! Thank you all for adding to this publication. I have once again changed the web format (thanks to input from readers). The number and sizes of graphics have been reduced to be more friendly to those who have slower access to the web. I have gotten rid of the busy frames. As usual, I would appreciate constructive input from web readers. You may find it at . The Accelerator Section will be losing one of its pioneers, Geoff Stapleton. Please read about this in the Jefferson Lab contribution. --------------------------------------------------------------------------- From the President Vashek Vylet --------------------------------------------------------------------------- Many of us involved in Accelerator Health Physics heard about a series of courses organized since the late seventies at the Ettore Majorana Centre for Scientific Culture in Erice, Sicily. Those who participated as either teachers or students invariably describe their experience in superlatives. These courses were part of the International School of Radiation Damage and Protection. Dr. Allessandro Rindi, director of the School, has been in contact with Ralph Thomas, our Past President Emeritus, in an effort to set up a course in the near future. Ralph thought that the Accelerator Section could get involved. He presented the issue in San Antonio to Lutz Moritz, Bob May and me. We were rather enthusiastic about this proposal but decided to proceed with caution and gather more information. It appears that the project will get financial support from the CEC (Commision of the European Communities), although it is not clear whether additional funding will be needed. Lutz Moritz has contacted the Ettore Majorana Centre to learn more about available time for the course and financing issues. The most desirable and available time at this moment seems to be November 2000, but the Center would prefer a commitment for a series of courses instead of an isolated event. These issues will be discussed within our Section Board before making any commitment. However, I believe that this exciting opportunity is worth pursuing. I have assigned Lutz Moritz as the coordinator of this effort, with Ralph Thomas, Bob May and me remaining as his helping hands. There will be an Accelerator Section Meeting during the upcomming HPS Midyear Meeting in Mobile. In order to avoid conflict with other events, I have reserved the usual time, i.e. 12 noon - 1 pm, on Monday, February 9. The exact location and program will be announced later. I would appreciate it if all those planning to attend could let me know by e-mail; a head count will be useful when reserving the conference room. In anticipation of the Accelerator Session at the HPS Annual Meeting, we are looking for a keynote speaker. It should be somebody from the area or who will be attending the meeting on their own, since we cannot afford a large travel expense. If you have any suggestions, please send them to Steve Musolino . Happy holidays to all! --------------------------------------------------------------------------- News from Alternating Gradient Synchrotron (AGS) Chuck Schaefer --------------------------------------------------------------------------- The AGS finished its polarized proton program in November. This 3 week run came on the heels of a 12 week high energy proton program. After a two week cooldown the Linac, Booster, main ring and target caves were surveyed and opened up for maintenance. The operational schedule as it stands now is for a four month shutdown followed by a six week heavy ion program commencing in mid-March. The high energy physics program will immediately follow this, and should continue for most of the rest of the year. One month will be dedicated running time for the g-2 experiment, which ran for the first time for five weeks this passed summer. The g-2 experiment uses a rotating nickel target to produce 3 GeV/c pions. The pions are used as a source of muons. It is the experiment's goal to improve CERN's previous measurement of the anomalous muon magnetic moment by a factor of 20. The experiment uses fast-extracted protons. The resultant prompt exposure rates outside of the target hall were slightly higher than expected by our health physics group. However, access is controlled, and the target hall is remotely situated. On a political note, the Secretary of Energy, Federico Pena, announced on 25 November the selection of Brookhaven Science Associates (BSA) as the new contractor to manage and operate Brookhaven National Laboratory. The Brookhaven Science Associates team is led by the Research Foundation of the State University of New York on behalf of the State University of New York at Stony Brook and Battelle Memorial Research Institute of Columbus, Ohio. BSA will replace Associated Universities Inc. which had managed the laboratory since its beginning in 1947. BSA will have a 5 year performance-based contract with performance measures in science and technology, environment, safety and health, and community involvement. --------------------------------------------------------------------------- News from Center for Advanced Microstructures and Devices (CAMD) Lorraine Day --------------------------------------------------------------------------- The CAMD wiggler project is in the installation and testing phase. The 11- member team arrived from Budker Institute in Novosibirsk, Russia on November 22nd. Since then they have been working hard. The baked out, reassembled magnet was placed into the CAMD storage ring on Dec 8th, with much trepidation as it was a 110% lift and only 6 inches of clearance for our crane. Initial cooldown is anticipated to start Thursday, December 18th. Interlocks and hutches are being built for radiation safety and the test beamline should be ready to go by December 26th. It will be an exciting Christmas (thought we'll all be working), for this represents the first insertion device for the CAMD Facility. Wishing everyone the best this holiday season. --------------------------------------------------------------------------- News from CERN Manfred Hoefert and Marco Silari --------------------------------------------------------------------------- Marco (MS) is dealing in his contribution with the rather early shut-down of CERN's major accelerators courtesy to energy conservation: The winter shutdown of the large CERN accelerators began on November 10 for LEP and on November 14 for the SPS. The ring survey of the SPS was carried out on 14 November, 30 hours after the machine was stopped. The levels of induced activity are somewhat higher that in the equivalent period of 1996. This is due to the fact that, following the fire of 13 May, the lead ion run which usually takes place at the end of the physics period (because it uses lower intensity beams and therefore ensures a better "cooling down" of the machine before major maintenance works) was canceled. The ring survey in the SPS was repeated on 3 December. At that date the dose rate has decreased to the same values as of 1996. The survey will be repeated in the first week of January, when the major maintenance intervention will start (until now work is only carried out in the "coolest" sextants, i.e. 3, 4 and 5). The survey in LEP was carried out in points 1 (injection region, where some induced activity at some well localized positions is produced by beam losses during injection), in the four straight sections centered at points 2, 4, 6 and 8, where the superconducting RF cavities are installed, and at points 3 and 7, around the polarization wigglers. Only a few, well localized "hot spots" are found around the RF cavities, with a maximum around 0.8 mSv/h at 10 cm distance from one cavity end. Typical values are much lower, usually not exceeding 10-20 microSv/h. In the injection region, the maximum measured was 60 microSv/h, lower than in the past. In the wiggler regions the dose rate is very low, of the order of 1 microSv/h. The survey will be repeated early in January, as it is known that a few weeks ensure a substantial decrease in the levels of induced activity. The major intervention carried out in LEP during this winter shutdown will be the dismantlement of several copper cavities at point 6, to leave room for the installation of eight superconducting modules (each consisting of four cavities), which will allow us to increase the LEP energy from 92 GeV to 96 GeV in 1998. In the experimental areas of LEP accessible during machine operation (ALEPH, DELPHI and OPAL) the integrated doses during the physics period (approximately five months) are of the order of 0.3 mSv on top of a background of 0.1 mSv. Remember the radiation level from natural radiation 80 m underground is only one half of that on the surface due to the nearly perfect shielding against cosmic radiation. In the rooms occupied by physicists they are even lower, about 0.25 mSv. (MS end) I (MH) would like to inform you about the latest developments in CERN's relation with the outside world. Two addenda were written of the Rapport de Surete in the framework of the Installations Nuclear de Base (INB) as far is LEP is concerned. This was necessary in spite of the fact that LEP will cease operation in 2000 to make room for the LHC. Technical planning for the LHC proceeds normally. With the civil engineering frozen the shielding requirements for the underground areas are defined. In 1998 the provisional INB report for the LHC should be finished addressing all safety aspects of the future installation. In the meantime the pressure of antinuclear groups in Geneva against the new project increases. CERN management has agreed to organize a public debate in the beginning of the new year on the topic "What CERN does and where it will go" to let some steam blow off (or further heat up the atmosphere?). Also in France some animated discussions are expected before the Declaration de l'utilite public (DUP) will be delivered as the prerequisite before any construction work can start. An interesting year comes to an end and there is an interesting year in perspective. So quite naturally I come to the end wishing all colleagues and readers of the IARPE Newsletter in the name of my group a Merry Christmas and a successful and healthy New Year, Manfred Hoefert --------------------------------------------------------------------------- News from DESY Herbert Dinter --------------------------------------------------------------------------- After a successful running period the big storage rings HERA (Hadron-Electron Ring Accelerator facility) and PETRA (Positron-Electron Tandem Ring Accelerator Facility) entered into a rather long shut down period at the beginning of November. At DESY usually the winter months are used for accelerator maintenance and installation work because of the high costs of electrical power in these "dark months". But nevertheless, last winter there was only a rather short interruption of the accelerator operation of a few weeks and new installations and modifications had to be postponed to this period. One major point of interest at HERA is the complete exchange of the ion getter pumps of the electron ring by non-evaporative getter (NEG-) pumps. The aim of this enormous effort is to increase lifetime and current of the e-minus-beam. As expected for an electron (or positron) storage ring no significant induced radioactivity was produced in the vacuum pipes so that no restrictions were necessary when machining the vacuum chambers. The second center of activity at HERA is the installation of the HERA-B experiment, the only fixed target experiment at a storage ring (as far as I know). Only the particles of the halo of the proton beam hit a wire target and produce B-particles, and the huge vessels and iron plates presently being installed are necessary to study the decay mechanisms of these exotic particles. Preliminary investigations performed with a test set-up ended successfully - successfully with respect to the production of secondary particles and with respect to additional background produced in other experiments. The radiation levels within the accessible part of the hall however will cause some effort to control in the next running period. The e-plus-storage ring DORIS, dedicated to the production and use of synchrotron radiation is in operation up to the middle of December. Its shut down period is shorter because of the many requests of users for beam time. Especially the medical application of the synchrotron radiation was very successful in this running period. Patients who had to undergo a cardial operation are examined by a non-invasive coronar angiography to check the success of the operation. More than 100 persons passed this procedure in the current year. The Radiation Protection Group of DESY maintains a collaboration with the Institute of Nuclear Physics in Krakov, Poland. Especially topics concerning theoretical aspects and calculational techniques of radiation protection are treated in this collaboration. We are glad to have Dominik Dworak working with us. --------------------------------------------------------------------------- News from Jefferson Lab Scott Schwahn --------------------------------------------------------------------------- We at Jefferson Lab have been busy with some scheduled year-end difficulties. There has been sort of a rush to get things done before the end-of-year shutdown (mandatory holiday/vacation time from December 25 to January 1). The Free Electron Laser (FEL) facility has gotten beam past the first superconducting half-cromodule, which has produced >5 MeV beam. Now this may not seem to be very much, but it was done very quickly due to the experience with "the big machine." They hope to have beam up to 40-50 MeV by January. One of the first experiments to be done will not actually be related to the lasing capabilities of the FEL. It will be an opportunistic irradiation of liquid ammonia in (separately) argon and liquid helium with the electron beam. The Radiation Control Group (RCG) will be taking this opportunity to make some confirmatory measurements of the integral shielding (i.e., the floor/ceiling between the accelerator vault and the user labs) and the penetration calculations. We are running three experiments in the three experimental halls for the Continuous Electron Beam Accelerator Facility (CEBAF) on a regular basis now. Our main focus for the Accelerator Division (under which the RCG resides as a support group) is to increase the fraction of time for which the accelerator is available for experiments. We went through the long ordeal over the last few months of putting out a competitive bid for our new dosimetry contract and have finally selected a vendor for the new year. This will involve us reapplying for DOELAP (Department of Energy Laboratory Accreditation Program) accreditation under the new vendor. We're all a bit blue here... Geoffrey Stapleton, a valuable colleague and friend, will be retiring. Geoffrey helped pioneer the Accelerator Section and served as President. He and Shirley will be spending a couple months with friends in Florida before moving to England in May. He may be reached by e-mail up until December 24 at and afterwards at . --------------------------------------------------------------------------- News from LNF Adolfo Esposito --------------------------------------------------------------------------- The first electron beam has been stored into the electron ring of the DAFNE collider on October 25, 1997 at 10:30 p.m. During a shift started at 2 p.m. the 510 MeV electron beam has been transported to the injection point of the electron Main Ring. With the RF cavity off it was possible to keep the beam inside the ring for ~0.3 ms, which is the maximum value allowed by the energy loss due to the emission of synchrotron radiation and the aperture of the vacuum chamber. The RF cavity was then switched on and the beam captured and stored in the ring. The position of the beam along the ring has been measured by means of the beam position monitors and found to be in agreement with the alignment tolerance. Multistacking was also successfully performed. On Tuesday, November 18, 1997, a new series of commissioning shifts was started by setting up the LINAC with positrons. After tuning up all subsystems, the nominal LINAC performance with positrons (33 mA @ 510 MeV) was reached with high reliability on Wednesday evening. It took about one hour to transport the beam correctly through the positron branch of the Transfer Line up to the fluorescent target at the entrance of the Accumulator. As expected (since the Accumulator is already working at the design performance with electrons), a first beam of 15 mA was immediately stored. The injection rate has been then improved and the stored current reached 35 mA. Extraction of the stored beam has also been successfully performed. After storing the first positron beam into the Accumulator on November 19, the following two days have been spent in optimizing the injection rate. Having reached more than 10 mA/s into the Accumulator, the commissioning of the Transfer Line from the Accumulator to the positron Main Ring was started. On Saturday, November 22 after lunch, the beam was driven on the fluorescent screen after the injection septum magnets. After half an hour, spent in tuning all the magnets, the first 0.5 mA positron bunch was stored at 4:30 p.m.. The measured lifetime at zero current was of the order of one hour. During the scheduled first 2 weeks of commissioning, on November 28, 1997, the single bunch design current (44 mA) has been exceeded in the positron ring of DAFNE. After optimizing the transport efficiency from the Accumulator to the Main Ring, and correcting the chromaticity by means of the sextupoles in the achromats, ~70 mA in a single bunch have been easily stored. Multibunch injection has also been successfully tested, reaching 250 mA limited by residual gas pressure in the vacuum chamber. No evidence of any instability has been so far detected. During the last series of commissioning shifts, dedicated to injection of positrons into the main ring, the Health Physics Group was working very hard. 1) Before any shift the access control system and the radiation system alarm of each part of the accelerator under commissioning were checked. 2) A lot of measurements were subsequently performed to characterize the radiation field outside the shieldings and to measure the residual radioactivity along the beam lines of the DAFNE complex. The major results obtained were: - to find and eliminate a "hole" in the shielding (concrete thickness not sufficient and no Pb bricks) with about 500 microGy/h in a location close to the access control system of the Damping Ring; - a measurement of about 400 microGy/h close to the positron converter 12 hours after the shutdown. --------------------------------------------------------------------------- News from LNLS Roberto Madacki --------------------------------------------------------------------------- Users have been working at LNLS (National Synchrotron Light Laboratory, Campinas BRAZIL) with synchrotron light since July 1, 1997. The ring has reached the design parameters: electron current of 100 mA at 1370 MeV with a lifetime of 7 hours. Seven beam lines are operational and 93 scientific works have been performed as of November, 1997. During injections users are requested to leave the experimental hall. All users are monitored with TLDs, all reading background. Skyshine is the main cause of the radiation levels at the experimental hall during injections. A roof above the Transport Line region after the thin septum is being installed. Merry Christmas and Happy New Year for all of you! --------------------------------------------------------------------------- News from Texas Bureau of Radiation Control Wesley Dunn --------------------------------------------------------------------------- Call for Papers The 16th International Conference on the Application of Accelerators in Research and Industry is scheduled for November 4-7, 1998. The meeting is held every other year and, as always, will be in Denton, Texas (30 miles North of Fort Worth and Dallas, Texas). I have been asked to chair a session on Health Physics and I am looking for speakers. At least two speakers should come from countries OUTSIDE of the United States. If you are interested in presenting a paper (or know someone who might be interested), please contact me. This is a premier conference for accelerator physicists and engineers and is a very good forum to present operational and theoretical health physics concepts and concerns to a very key audience. Poster papers are welcome and all papers will have 4 pages in Nuclear Instruments and Methods. Advance registration (before October 1, 1998) is $270 and includes a copy of the proceedings and a book of abstracts. Contact: I am changing jobs, so any email to this address is questionable. You can try leaving a message at my wife's email . Mail will reach me at: Wesley Dunn P.O. Box 2608 Denton, Texas 76202-2608 As of January 1, 1998, you can also reach me at: Wesley Dunn International Isotopes 3100 Jim Christal Road Denton, Texas 76207 940-484-9492 --------------------------------------------------------------------------- HOW TO SUBSCRIBE / UPDATE YOUR E-MAIL ADDRESS --------------------------------------------------------------------------- To add yourself to the mailing list for the IARPE Newsletter, send an e-mail message to listserv@slac.stanford.edu The body of your message should contain the following command: subscribe iarpe-l Please don't forget to update your e-mail address if you move, change jobs or just change your computing environment. The update consists in canceling the old by 'unsubscribe' and submitting a new subscription, as illustrated below: unsubscribe iarpe-l your_old_email_address subscribe iarpe-l end If the body of your message, as in this example, contains more than a single line/command, it is good practice to finish with the 'end' command, especially if your mailer adds a signature. If you experience problems with subscribing/updating, please send me an e-mail to schwahn@jlab.org and I will do it for you. --------------------------------------------------------------------------- Closing Thought --------------------------------------------------------------------------- "The great tragedy of Science: the slaying of a beautiful hypothesis by an ugly fact" Thomas Huxley, English biologist (1825-1895)