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 1998 Circulation: 200 Vol.7, #1 --------------------------------------------------------------------------- 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 From the Editor From the President News from correspondents: AGS CAMD CERN Fermilab Jefferson Lab The Macdonald Laboratory Other News: Second Call for Papers WAO '98 How to subscribe or update subscription Closing thought --------------------------------------------------------------------------- From the Editor Scott Schwahn --------------------------------------------------------------------------- In this newsletter, you will find updates from AGS, CAMD, CERN, Fermilab, Jefferson Lab, and The Macdonald Laboratory. In the last edition of the Newsletter, the AGS had a contribution that did not make it by the deadline, but I went ahead and published it in the online version, now in the archive at . Ted DeCastro's ASCII archive of this edition is at , which has been updated to include the AGS report. Vashek's report from the President includes a summary of what happened at the mid-year business meeting, so please read it carefully. Jefferson Lab's report has some good graphics in the web version, but they can also be downloaded via FTP as described in the article. Enjoy! --------------------------------------------------------------------------- From the President Vashek Vylet --------------------------------------------------------------------------- The few members of our Section who were able to attend the HPS Midyear Meeting in Mobile met for an Accelerator Section meeting on Monday, February 9. In the first part of the meeting I presented the Midyear Section report prepared for the HPS Board of Directors - the full copy of the text is enclosed below. Several topics (CASOG, neutron calibration facilities) generated further discussion and useful suggestions, which will appear in the minutes of the meeting. Accelerator Section finances are healthy, with over $6000 in the bank. $1000 will be transferred to the Moyer fund, as agreed before the San Jose Midyear meeting. Richard Burk (HPS Executive Secretary and our designated contact person with the HPS Board) informed me that the Board approved our Amendment to the Accelerator Section Bylaws. This ammendment was proposed in order to enable votes by proxy or e-mail. Speaking about elections, I am pleased to announce that Ralph Thomas accepted the appointment as Chair of the Nominating Committee. Ralph selected two past Presidents as additional members of his committee: Bob May and Lutz Moritz. Please exercise your member rights and respond to their call for nominations when they request it. ACCELERATOR SECTION MIDYEAR REPORT (2nd half of 1997) Author: Vashek Vylet, Section President Date: January 9, 1998 During its meeting in San Antonio the section elected its new officers, whose names were later communicated to the HPS Secretariat. Immediately after the meeting and in accordance with the Section Bylaws, the new president appointed section members to existing and newly created committees. The salient activities and initiatives of the section are listed below. CASOG (Committee on the Accelerator Safety Order and Guidance) The work of this committee, set up in 1994, reflects a major effort by the section to become an active player in the regulatory process. This work will result in the publication of a paper (hopefully this year) that documents section's position on methods for establishing safety standards at accelerator facilities. The proposed concept provides a rational way of establishing reliability levels of safety systems needed to control risk of radiation exposure. It is hoped that the approach outlined in this paper will be implemented in future regulation pertaining to accelerator facilities. Summer School The section would like to contribute to the Summer School program by organizing a course on Accelerator Health Physics. Two Accelerator Section Board members met with the HPS Summer School Committee and discussed this issue in San Antonio. Contacts are being made to include this course in the 1999 Summer School in Colorado. International School Efforts are in progress to revive the "International School of Radiation Damage and Protection", organized since the late seventies at the Ettore Majorana Center for Scientific Culture in Erice, Sicily. The Accelerator Section is proposing to organize the program and find teachers for the selected courses. Our target is to have the first two-week course in November 2000, possibly followed by similar courses every two or three years. We were able to secure the support of the European Community for the first course in the amount of 20,000 ECU (approximately $30,000) and started negotiations with the Ettore Majorana Center. Electronic Newsletter The section continues to publish its electronic newsletter IARPE (International Accelerator Radiological Protection E-mail), which is distributed via listserv to approximately 200 readers worldwide. It is also available on the World Wide Web (current link: http://www.sura.org/~schwahn/iarpe.html). High Energy Neutron Calibration Facility Unites States lags behind Europe and Japan in that it has no facility providing well calibrated beams of mono-energetic neutrons, and high energy neutrons (above 20 MeV) in particular. That means that accelerator health physicists have very little means of calibrating their neutron instruments in the high-energy area. The Accelerator Section is exploring different possibilities and will continue lobbying for and encourage any effort to establish such a facility in the US. Financial Report (As communicated by the HPS Secretariat) Statement of Income & Expenses and Account Balance For the 8 month period ending 12/31/97 ACCOUNT BALANCE 4/30/97 3771.61 INCOME RECEIVED Dues from HPS Members 325.00 HPS Meeting Payment 2000.00 TOTAL INCOME COLLECTED 2325.00 EXPENSES PAID Collection & Management 0.00 Annual Meeting Expenses 0.00 TOTAL EXPENSES PAID 0.00 ACCOUNT BALANCE 12/31/97 6096.61 --------------------------------------------------------------------------- News from AGS Chuck Schaefer --------------------------------------------------------------------------- The AGS is nearing the end of a four month shutdown. There has been less radiological work than expected. This is mostly due to increasingly significant efforts being expended at getting the Relativistic Heavy Ion Collider read for commissioning in 1999. One large AGS undertaking has been the re-design of the C3 beam line. Historically, due to poor beam transport optics, the water-cooled magnets in this line have experienced heavy activation. In turn, the magnet water, most of which is recirculated to a cooling tower outside of the experimental building, has been responsible for a small cooling tower plume containing the short-lived radiogases C-11, N-13, and O-15. This plume has proven to be a nuisance to other on-site operations as the AGS's intensity has surged in recent years. For example, when the wind is from the north and the AGS is operating at high intensity, the High Flux Beam Reactor portal monitors, to the south of the AGS, will periodically alarm. In order to reduce emissions from this cooling tower, the AGS has instituted several measures such as the inclusion of a closed loop heat exchanger which prevents some primary magnet water from being recirculated to the cooling tower. As mentioned above, the C3 line upgrade is expected to further reduce emissions by installing a copper collimator. The collimator's main job will be to reduce the activation rate of downstream magnets from the beam halo. Its cooling water will also be placed on the closed loop heat exchanger. Additional C3 magnet cooling water will likewise be placed on the same closed loop heat exchanger. These improvements are expected to lower the cooling tower radio gas emissions by a factor of three. The AGS is also expected to approve the design of a beam scraper which will be placed in a less traveled area of the main ring. The scraper's design is supposed to allow for essentially all ring activation to occur at one point, rather than being spread out over many loss points. This project has been primarily motivated by the ongoing concern of keeping radiation doses as low as reasonably achievable. Presently, most of the activation occurs in the extraction magnets. Repeated failures in several of these elements have caused heavy doses to be incurred during repairs. The beam scraper will be well shielded and water-cooled. Installation is expected later this year. --------------------------------------------------------------------------- News from Center for Advanced Microstructures and Devices (CAMD) Lorraine Day --------------------------------------------------------------------------- As we mentioned in the previous newsletter we were extremely busy with the installation and commissioning of the 7.5 tesla super-conducting wiggler. Commissioning was only partially successful. We were able to store beam with up to 1 tesla magnetic field. The first tesla is the hardest. However, we had machine difficulties and were unable to ramp. Stored current is still low. Testing of the in-place wiggler showed a magnetic field of only 5.3 tesla. The magnet will be shipped back to Russia for re-furbishing. Meanwhile, the 4200 lb (1909 kg) magnet offers good self-shielding and no additional health physics problems. Other projects include the commissioning of four new beamlines in the near future. We are busy with calculations. Outside interests at the university have decided to build a three-story office building within 200 feet of the facility. No one thought to inform the radiation safety staff and we only found out by accident. Initial calculations show line of sight problems from 13 to 50 feet in height for the proposed building. These calculations will be followed up by experimentation. Those of you who are familiar with the CAMD facility might be aware that the storage ring has no radiation cover or roof over the ring. These new changes are troublesome and may represent some serious health physics considerations. We continue to move towards the installation of PLC's (programmable logic controllers) for our radiation interlock beamline controls. Re-evaluation of hutch thicknesses and construction is also being done at this time. A new NIM (normal -incidence monochromator) beamline design has been approved. The unique structure of this beamline could make the installation (at least in the classical sense) of bremsstrahlung shutters obsolete. So it is calculate, calculate, calculate! - so off to work I go. --------------------------------------------------------------------------- News from CERN Manfred Hoefert et al. --------------------------------------------------------------------------- From Marco Silari : A Gamma Irradiation Facility (GIF) has recently been set up at CERN, downstream of the final dump of the X5 beam, one of the secondary beam lines of the West Experimental Area of the Super Proton Synchrotron. This zone has been equipped with a 740 GBq (20 Ci) Cs-137 source which is used to irradiate, in two different positions, large detectors (with dimensions up to 6 m x 3 m) developed for the future experiments at the LHC. The aim is to irradiate the detectors with a low muon flux (1.0E4 muons per SPS pulse) from the X5 beam and measure the effect of a photon background on the detector response. A possibility of varying the photon flux in a controlled way is provided by a set of mobile lead filters that are in addition shaped to provide a constant fluence over the large surface of the detector. GIF is used by various groups (mainly from the ATLAS and CMS collaborations), but there is only one main user at a time, who is responsible for the source operation. The irradiation area is surrounded by concrete walls (8.4 m high and 80 cm thick) and is covered by a grid roof. Access is via a standard PPE (Personnel Protection Entry) door, with an emergency exit provided on the other side of the area. The large chambers are introduced into the zone through a gate close to the PPE door. For the first time in CERN history, safe operation is not assured by an accelerator Division but by the Physics Division, a fact that caused many political discussions and practical considerations. The safety aspects of the GIF are indeed mainly dictated by the operation of the gamma source, the muon flux being too weak to pose any radiation hazard. A search procedure of the area is required before the zone can be locked; the same (and unique) key which gives access to the zone must be inserted in the console controlling the operation of the source, such that the source can leave its shielded position only if the area is cleared and locked up. Naturally, the operation of the source is interlocked with the operation of the beam line, as particles other than muons (e.g., electrons) could in principle be transported in the X5 beam. Radiation monitors, movement detectors, fire and gas detectors complete the safety system. From Thomas Otto : Two developments in the field of radiation measurements came to a successful end in January in the Dosimetry and Calibration Section: During his six-months stay in the Radiation Protection Group a Technical Student from the Universitat Karlsruhe designed a detector to track down weak radioactive sources. Its principle of operation is to observe a rise in count rate over background, indicating the presence of activated material. The detector uses a BGO-scintillator, giving less photoelectrons per MeV than the classical NaI(Tl)-crystal, but having for gammas of all energies a higher interaction probability that "counts" in a pulse-counting application. A special requirement was that the detector unit should be coupled to a universal portable basic unit rate meter already in wide use in our group. The device has an autonomy of 50 hours on four 1.5 Volt cells. We are now going out for tender to find a supplier for about 10 units according to the student's design. CERN still uses films, the Kodak Type 2, for individual gamma- and beta-dosimetry. It is an individual monitor of a reasonable price and has the additional benefit of allowing to identify the radiation hardness to which a person was exposed to. At the end of January, an automated development laboratory for this type of film was installed replacing the existing equipment. A robot is now transferring baskets loaded with exposed films through the whole development process. Thus, process times are precisely controlled. Furthermore, a regeneration system injects fresh processing chemicals at the end of each development in order to keep the chemical concentrations at constant levels. The laboratory was constructed by a specialized French firm according to CERN's requirements. We are now tuning the parameters of the machine with the goal to ensure the reproducibility in the dosimeter evaluation within stricter limits than before. From Manfred Hoefert : STOA, but no indifference. On 5 February I assisted in a one day workshop that had been organized by STOA. Although the invitation had come from Prof. P. A. Assimakopoulos, University of Ioannina, Greece, STOA has nothing to do with the ancient philosophical school but stands for the unit of Scientific and Technological Options Assessment of the European Parliament in Brussels. In fact, this workshop was meant to help members of Parliament in their "survey and evaluation of criticism of basic safety standards for the protection of workers and the public against ionising radiation" notably the European Directive based on ICRP Recommendation 60. Invited oral contributions from both mainstream supporters of the present radiation protection standards and from adversaries of nuclear energy were well mixed with even some presentations by speakers making the point that current radiation protection efforts were excessive and hence too expensive. While except for a few wild i.e. unfounded statements of those who drove fundamental attacks against the existing radiation protection system these contributions repeated already well known standpoints. However, some arguments emerged that were not easily refutable during the generous discussion periods of an hour, following the four topics : * The current debate on basic safety standards for the protection of workers and the general public * Ionizing radiation and biological systems * Risk assessment and * Legitimation, validation and implementation. Although the discussion was rather intended to concentrate on the EU Directive on radiation protection it was ICRP, the originator, who was pilloried. Should we believe the statement of Dr. R. Bertell, International Institute of Concern for Public Health, Toronto, Canada, that the original ICRP dose limit of 5 rem per year for workers was forwarded before the first dose effect estimations for the victims from Hiroshima and Nagasaki had even been made? If therefore the agreement between these estimations and the dose limit was fortuitous, what shall we then think of the remark by Dr. A. Stewart, the impressive and venerable 92 years old lady from Birmingham, that the bomb data are not representative for risk estimations as they are "strongly biased in favour of persons who were exceptionally resistant to all (early and late) effects of radiation". Is it so that persons with a weak immune system are also more sensitive to radiation such that this cohort simply died out due to infections in the years following the explosions? Does this mean that ICRP have lost their basis of risk estimations? But not only questions arose but strong arguments against IRCP practices were voiced, like: * Scientific risk estimations must be separated from questions of acceptability, * the Commission should even not make judgments on risks as this must be left to people who are better educated in these matters, * it should not be left to ICRP to determine what is acceptable to individuals and society, or even more radical * nobody can decide on the detriment and benefits of other people. A final question posed by Green Audit, UK whether it is true that the Commission is composed of 50% nuclear physicists and only counts one woman in its ranks was left unanswered. The concept of effective dose was another point of attack by those who consider present standards not being sufficiently conservative. This not because ICRP has fowled it up for those who must deal with neutrons for whom effective dose equivalent is a more logical quantity than effective dose. Contrary to effective dose equivalent Dr. D. Sumner, Moss park, Scotland, said that the quantity effective dose incorporates "value judgments" on issues like the quality of life for non fatal cancers. Furthermore there are uncertainties in weighting factors, the combination of doses from as varied sources as alpha, beta, gamma and neutrons is wrong and the "calibration" of effective dose with respect to radiation risk could be way off. Dr. C. Busby, Green Audit, Wales continued that effective dose is not a suitable risk quantity because of the averaging performed in space and time when radiation interacts. Hence hot particles from nuclear power are not correctly considered and may be the reason for so far unexplained local effects observed in the vicinity of nuclear installations where also high plutonium values that are 1000 times higher than natural? could be the origin. In fact, the clusters in children's leukemia strongly came up again presented by (the now in France famous) Dr. Viel Besancon, the man who had explained the cluster near the treatment plant in La Hague, France, by the use of nearby beaches, the local fish diet but also by residence in granite houses that are common in Brittany. At the same time he supported Gardener's hypothesis that the paternal employment in Sellafield was the reason for the increase in offspring leukemia. Alice Steward said that leukemia clusters have always been observed, more in rural areas than in cities and most of them are not explained. With respect to the leukemia in children around the nuclear power plant in Krummel near Hamburg Dr. H. Ziggell, Physics office, Bremen, Germany, admitted that the latest models did not explain why 11 cases were observed with only one expected, but he insisted that there must be some correlation with nuclear power (any hidden parameters?). A request for a dramatic decrease in present dose limits came from Prof. H. Kuni, University of Marburg, Germany: the annual occupational dose limit should be decreased from 50 mSv to 1 mSv and for the public doses should be lowered from 1 mSv to 20 microSv annually. One of the many arguments forwarded to support this decrease was that ICRP had always compared radiation risk with professional risk figures in safe industries but not considering that the latter had been steadily decreasing over the years. Subsequently dose limits should follow. Apparently he had overlooked that personal doses had been decreasing over the years too and that nuclear installations in Germany already limited by law with their radioactive emissions to 300 microSv/year for the surrounding population will proudly present the results of environmental measurements showing that they stayed at least one order of magnitude below the legal limit. As far as neutrons are concerned Prof. Kuni pointed out that radiobiological evidence calls for an increase in their weighting factor to 75. Would 80 or even 100 not have been a rounder figure? On the other hand present standards in radiation protection were attacked as leading to much too expensive measures in comparison to what could be achieved with the same amount of money when invested to decrease other common daily risks. Prof. J. Jovanovich, University of Manitoba, Canada, presented the audience with the true story of a friend who had asked him whether he should rather invest Can$ 5000 in diminishing the radon concentration in his house than improving its fire safety. Knowing that the risk to die in a house fire in the States or Canada is indeed double compared with Europe the answer seemed already clear when Prof. B. Cohen, Pittsburgh University, US, presented his well known dose effect curves for radon in American houses showing a clear hormesis effect. This was supported by Prof. K. Becker, RSH Berlin, Germany who showed data on the effect of radon concentration on the lung cancer rate of non smoking women from the former Uranium mine area of Thuringia. These facts suggest that the radon risk in houses where and when the synergetic influence of dust and smoking generally experienced with miners is absent is a red herring. A correlation between all those findings and the now famous 200 mSv threshold dose in man is however audacious. In this context the official position of the Protection Office against Ionizing Radiation (OPRI) in France is fully in line with ICRP Recommendation 60. They did not retain the result of the study asked for by the French Academy of Sciences on the dose threshold hypothesis. Nevertheless the sums invested in radiation protection in particular for "cleaning up" Chernobyl in West European countries alone go into hundred of millions whereas the sums spent on radon sanitation exceed billions of dollars according to Prof. Becker. This naturally explains Prof. Jovanovich's remark that ICRP would be well advised to admit economists in its ranks. At two occasions in the discussion the author tried to turn the discussion back to the European Directive. My remark that although exemption values for radioactive materials are common in Europe but the choice or even refusal of Clearance levels are left over to the individual member states. Such a decision hampers the free passage of goods among the EU countries and hence was against the basic treaty of the Community. My remarks found the full support of M. P. Lannoye, French member of the European Parliament and chairman of one of the sessions. Members of the European Commission's Unit DG XI present at the workshop announced improvements and the imminent publication of a paper on the recycling of weakly radioactive scrap metal that is in its final draft. However, my other question, why the EU retained in their Directive class A and B radiation workers although ICRP does no longer make this distinction did not find much interest. The answer of the European Commission that existing structures had to be retained sounds weak considering that: * most of the persons who with the old dose limits had been class B now find themselves suddenly in class A, * there was and there will in most practices be no difference in personal monitoring between the two classes for it is recognized that a low or zero dose registered on the official, legal dosemeter will assure both worker and employer and * medical surveillance of all persons exposed in the exercise of their profession should be part of a general preventive occupational medicine comprising all professional risks. In particular exposure to the low radiation doses experienced nowadays should only be considered as one professional risk among many others. Such an attitude however is not acceptable as long as in many countries values of personal doses are still regarded as medical information. --------------------------------------------------------------------------- News from Fermilab Don Cossairt --------------------------------------------------------------------------- At the conclusion of Fermilab's Fixed Target Run in November 1997, a lab-wide radioactive source collection was initiated. Radioactive source users were contacted to determine whether sources issued in their name were still being used. All sources that were no longer in use were systematically collected and returned to ES&H Section storage. Approximately 500 radioactive sources were on loan to users during the run. About 90 of the 500 were collected and returned to storage. The remainder are still needed to support the experimental research program. The 18% reduction in the number of sources on loan has several advantages. The reduced number of sources on loan reduces the vulnerability for loss of control of sources and also reduces the potential for occurrence of a source incident. Finally, the collection of these sources eliminated several locations where sources were being used. The reduced number of locations decreases the amount of time required to conduct monthly source inventory and leak testing. Fermilab is making significant progress with respect to the Neutrinos at the Main Injector (NuMI) project. This new effort consists of the design, construction, and operation of a neutrino beam which will be used to study neutrino oscillations. Such oscillations, if discovered, will mean that neutrinos, long thought to be massless, actually have a small non-zero mass. The scientific implications of such a discovery are immense in nuclear physics and particle physics as well as in cosmology. The neutrinos will be produced as a result of the targeting of an intense beam of 120 GeV protons produced by the new Fermilab Main Injector. These neutrinos will be studied by two experiments. One is a short baseline experiment housed entirely on the Fermilab site while the other consists of two detectors: one located on the Fermilab site and the other housed in the decommissioned iron mine in northeastern Minnesota known as the Soudan Underground Laboratory. This project has a number of interesting radiological problems which are presently being studied very carefully at Fermilab. The beam intensities are very large, approximately 2 E13 protons per second. The result will be the creation of highly radioactive beam focusing components which must be maintained. Groundwater protection issues are very important as most of the beam components are located deep underground. Airborne radioactivity issues are non trivial and are just now beginning to be addressed. Above ground issues with respect to prompt radiation are minimized due to the fact that the entire beam line is pitched downward by 3.3 degrees in order to result in neutrinos being direct toward Minnesota. This results in the downstream end of the beamline being more than 200 feet underground. The environmental protection issues have been successfully addressed in concept in an Environmental Assessment which resulted in a so-called "Finding of No Significant Impact". The detailed design effort is just now beginning and will continue to challenge us for some time. The occupational protection issues are being addressed in connection with a safety assessment document that is presently under preparation. A review was recently held of the controls set in place for radiochemistry at the 10.5 MeV 3He++ Positron Emission Tomography (PET) Radiofrequency Quadrupole (RFQ) Accelerator at Fermilab. The first radiochemistry "run", irradiating gases and liquids, was in mid December. This review was to see if the controls, training and oversight were sufficient for such work. The controls were found to be adequate. The radiochemists have been given specialized training and have helped write an extensive ALARA plan for their work. Much of the oversight is performed by the PET Crew Chiefs who are specially trained to oversee the chemists' work. The accelerator has not been working very reliably and thus the chemists doses to date are quite low. The hopes are to get more beam on the chemists' targets and thus the chemists' doses will increase. --------------------------------------------------------------------------- News from Jefferson Lab Scott Schwahn --------------------------------------------------------------------------- As I mentioned in the last newsletter, we have selected a new dosimetry provider. Since we were going through the process, we decided to update our technical basis manual to reflect our most recent advances in calculation capabilities and to reflect this ability into the choice of neutron dosimetry. Prior to the switch-over, we were using a four-chip TLD badge, all TLD-700, with CR-39 for neutrons. Now, we are using a TLD badge that has 3 TLD-700 and 1 TLD-600 chips with CR-39. We have been operating on the basis that the neutron spectrum through thick shielding is adequately approximated by an Am-Be spectrum. This assumption had been supported by technical notes, verbal communications, and references from other similar facilities, but had not been independently confirmed for Jefferson Lab. As a result, we have always had our neutron dosimetry and instruments calibrated for the Am-Be spectrum. We also did this because our main source of exposure was from our Am-Be calibration source rather than from the accelerator itself. Our group radiation physicist, Pavel Degtiarenko, calculated several neutron spectra based on typical target configurations, shield geometry, energies, distances, etc., using DINREG/GEANT. We looked at both skyshine and exit spectra. The results show that the spectrum from skyshine (which we believe to be most representative of dose to employees and to the site boundary) is remarkably close to the spectrum from Am-Be. It is also very close to the unmoderated Cf-252 source which is used in our DOELAP (Department of Energy Laboratory Accreditation Program) irradiations. Our dosimetry provider performed several irradiations of both the TLD/CR-39 badge to determine a calibration factor for processing the badges, comparing the Am-Be irradiations to the Cf-252 irradiations. The CR-39 responded virtually identically in both fields; the TLD badge responded slightly differently. The next step in the process is to develop a method for determining dose retrospectively to a person believed to have been exposed in an unexpected location, e.g., from exiting flux rather than skyshine. We will be doing this in the next couple months and hopefully will be publishing the results in some fashion. We have submitted a new DOELAP application to take into account our new vendor and the new dosimetry. If you are interested in looking at our preliminary conclusions, which include calculated spectra, you can download the Postscript file from the following location: (714 KB). --------------------------------------------------------------------------- News from The Macdonald Laboratory Tracy Tipping --------------------------------------------------------------------------- A recent expansion of our Rydberg target atom project here at the Macdonald Laboratory has necessitated the addition of a new laser system. The laser in this new system is a 1.2 watt CW infrared diode. This is not the first Class IV laser we have had here, but the invisible beam is a new challenge to us. The other Class IV laser system at the Macdonald Lab is a copper vapor laser which lases in the visible range. The researchers working with the copper vapor laser found it a comfort to know immediately when an optics element was not properly aligned. The location of the beam from the copper vapor laser was very evident from the eerie yellow-green glow. The new IR diode laser will not be as easy to track and will require greater attention to assure that the beam really is where we think it is. The researchers who are setting up the optics for this laser system are already practicing the fine art of infrared snooping. In the past, we used the copper vapor laser as a pump laser for less powerful dye lasers. The beams from the dye lasers then went out to the target chamber. The copper vapor laser was completely contained in an interlocked enclosure to avoid exposure to people in the target area. The beam from the new IR laser will be used in the target chamber. So now our Class IV laser enclosure must extend to and include the target chamber. We are in the process of designing a totally enclosed beam transport system for the new IR laser. In essence, we are adding a beamline to the Rydberg target area. This new beamline just happens to be perpendicular to the accelerator beamlines and does not require large magnets to make 90-degree bends. Although this article is not about a traditional accelerator health physics concern, it does have to do with a radiation safety concern which is becoming more of a part of our daily lives as health physicists. Since I do not consider myself an expert in non-ionizing radiation protection, I am enjoying as a learning experience, the changes in our lab that I described. --------------------------------------------------------------------------- 16th International Conference on the Application of Accelerators in Research and Industry Wes Dunn --------------------------------------------------------------------------- Second 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 additional 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 as soon as possible (a list of presenters must be submitted in March). I have a suggestion to focus on radioactive accelerator waste, and papers on this topic would be well received. However, do not feel constrained to limit papers to that topic. 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. Abstracts will be due July 1, 1998 and manuscripts must be submitted by October 1, 1998. Publication by the American Institute of Physics will be April 1999. Wesley M. Dunn, CHP, Director, Environmental Health and Safety International Isotopes, Inc. 3100 Jim Christal Road Denton, Texas 76207 Wdunn@intiso.com 940-484-9492; 940-484-0877 (fax) --------------------------------------------------------------------------- Workshop on Accelerator Operations '98 --------------------------------------------------------------------------- A second general mailing has been made concerning the Workshop on Accelerator Operations '98. For more information for you or an associate, please refer to the IARPE HTML archive, found at ,the September/October IARPE Newsletter, or the WAO '98 homepage . --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- "For it is said that humans are never satisfied, that you give them one thing and they want something more. And this is said in disparagement, whereas it is one of the greatest talents the species has..." -- John Steinbeck Think of all the great accomplishments which have come about because people were not satisfied with the way things were. We are never satisfied, yet we continue to pursue satisfaction. In the process we achieve some measure of greatness. We invent, we create, we express, we cooperate, we build, we challenge and we think, all because we can never be completely satisfied. Fulfillment comes not from ever reaching a state of absolute satisfaction, but rather from continually moving toward it. If we ever achieved absolute satisfaction, we certainly would not be satisfied with it. There would no challenge against which it could be applied. Just as money would be worthless if there was nothing to buy, the sense of satisfaction we get from our accomplishments would be useless if there was nothing more to accomplish. There's always something more to be done. Find your joy in doing it. THE DAILY MOTIVATOR, Wednesday, February 11, 1998