DOCSLIB.ORG

Cyclotron Produced Radionuclides

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

280 pages 16.4 mm technical reportS series no. This publication contains radioisotope decay and production details of 49 isotopes that can be prepared using cyclotrons. The introductory chapter discusses the principles of radioisotope production using cyclotrons, while Chapter 2 contains data on nuclear decay characteristics such as half-life, mode of decay, energy and 468 abundance, nuclear reactions and excitation functions of the selected isotopes. This Technical Reports SeriEs No. Cyclotron Produced Radionuclides: Physical Characteristics and Production Methods 468 publication will be of interest to scientists and engineers working in radioisotope production using cyclotrons. Cyclotron Produced Radionuclides: Physical Characteristics and Production Methods INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA ISBN 978–92–0–106908–5 ISSN 0074–1914 D468_covI-IV.indd 1 2009-02-04 10:25:19 CYCLOTRON PRODUCED RADIONUCLIDES: PHYSICAL CHARACTERISTICS AND PRODUCTION METHODS The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GUATEMALA PAKISTAN ALBANIA HAITI PALAU ALGERIA HOLY SEE PANAMA ANGOLA HONDURAS PARAGUAY ARGENTINA HUNGARY PERU ARMENIA ICELAND PHILIPPINES AUSTRALIA INDIA POLAND AUSTRIA INDONESIA PORTUGAL AZERBAIJAN IRAN, ISLAMIC REPUBLIC OF QATAR BANGLADESH IRAQ REPUBLIC OF MOLDOVA BELARUS IRELAND ROMANIA BELGIUM ISRAEL RUSSIAN FEDERATION BELIZE ITALY SAUDI ARABIA BENIN JAMAICA SENEGAL BOLIVIA JAPAN SERBIA BOSNIA AND HERZEGOVINA JORDAN BOTSWANA KAZAKHSTAN SEYCHELLES BRAZIL KENYA SIERRA LEONE BULGARIA KOREA, REPUBLIC OF SINGAPORE BURKINA FASO KUWAIT SLOVAKIA CAMEROON KYRGYZSTAN SLOVENIA CANADA LATVIA SOUTH AFRICA CENTRAL AFRICAN LEBANON SPAIN REPUBLIC LIBERIA SRI LANKA CHAD LIBYAN ARAB JAMAHIRIYA SUDAN CHILE LIECHTENSTEIN SWEDEN CHINA LITHUANIA SWITZERLAND COLOMBIA LUXEMBOURG SYRIAN ARAB REPUBLIC COSTA RICA MADAGASCAR TAJIKISTAN CÔTE D’IVOIRE MALAWI THAILAND CROATIA MALAYSIA THE FORMER YUGOSLAV CUBA MALI REPUBLIC OF MACEDONIA CYPRUS MALTA TUNISIA CZECH REPUBLIC MARSHALL ISLANDS TURKEY DEMOCRATIC REPUBLIC MAURITANIA UGANDA OF THE CONGO MAURITIUS UKRAINE DENMARK MEXICO UNITED ARAB EMIRATES DOMINICAN REPUBLIC MONACO UNITED KINGDOM OF ECUADOR MONGOLIA GREAT BRITAIN AND EGYPT MONTENEGRO NORTHERN IRELAND EL SALVADOR MOROCCO UNITED REPUBLIC ERITREA MOZAMBIQUE ESTONIA MYANMAR OF TANZANIA ETHIOPIA NAMIBIA UNITED STATES OF AMERICA FINLAND NEPAL URUGUAY FRANCE NETHERLANDS UZBEKISTAN GABON NEW ZEALAND VENEZUELA GEORGIA NICARAGUA VIETNAM GERMANY NIGER YEMEN GHANA NIGERIA ZAMBIA GREECE NORWAY ZIMBABWE The Agency’s Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Headquarters of the Agency are situated in Vienna. Its principal objective is “to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world’’. TECHNICAL REPORTS SERIES No. 468 CYCLOTRON PRODUCED RADIONUCLIDES: PHYSICAL CHARACTERISTICS AND PRODUCTION METHODS INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 2009 COPYRIGHT NOTICE All IAEA scientific and technical publications are protected by the terms of the Universal Copyright Convention as adopted in 1952 (Berne) and as revised in 1972 (Paris). The copyright has since been extended by the World Intellectual Property Organization (Geneva) to include electronic and virtual intellectual property. Permission to use whole or parts of texts contained in IAEA publications in printed or electronic form must be obtained and is usually subject to royalty agreements. Proposals for non-commercial reproductions and translations are welcomed and considered on a case-by-case basis. Enquiries should be addressed to the IAEA Publishing Section at: Sales and Promotion, Publishing Section International Atomic Energy Agency Wagramer Strasse 5 P.O. Box 100 1400 Vienna, Austria fax: +43 1 2600 29302 tel.: +43 1 2600 22417 email: [email protected] http://www.iaea.org/books © IAEA, 2009 Printed by the IAEA in Austria February 2009 STI/DOC/010/468 IAEA Library Cataloguing in Publication Data Cyclotron produced radionuclides : physical characteristics and production methods. — Vienna : International Atomic Energy Agency, 2009. p. ; 24 cm. — (Technical reports series, ISSN 0074–1914 ; no. 468) STI/DOC/010/468 ISBN 978–92–0–106908–5 Includes bibliographical references. 1. Radioisotopes in medical diagnosis. — 2. Cyclotrons. I. International Atomic Energy Agency. II. Series: Technical reports series (International Atomic Energy Agency) ; 468. IAEAL 08–00552 FOREWORD Radioisotopes find applications in nearly all the countries of the world, contributing significantly to the improvement of health care and industrial output, as well as safety. Globally, the number of medical procedures involving the use of isotopes is constantly growing, and these procedures require an increasing number of different isotopes. In industry, isotope uses are very diverse, but their relative importance in the various sectors differs greatly. However, in general, isotopes are required where they are more efficient than the alternatives or have no substitute. The IAEA has been helping Member States in the development of technologies for the production, radiochemical processing, safe transport and applications of radioisotopes. IAEA publications, such as Radioisotope Production and Quality Control, published in 1971, were the reference publications used by many developing Member States for establishing their radioisotope production programmes. A recent publication, Manual for Reactor Produced Isotopes, published in 2003, elaborated on the production and radiochemical processing of 48 important reactor produced radioisotopes. The IAEA published a directory on cyclotrons used for isotope production in 1998, and revised versions were published in 2002 and 2006, which documented the cyclotrons available in Member States. The last 15 years have seen the installation of a large number of new cyclotrons for isotope production. Many of these are dedicated to the production of a single isotope or a small group of isotopes. However, the majority of them have spare capacity for the production of many other useful isotopes, and this capability needs to be explored. The IAEA has been extending support in various forms to Member States to acquire or enhance the technology they have for the production of isotopes using cyclotrons. The publication of reports covering different aspects of radioisotope production using cyclotrons has been one activity that has been identified which needs further input and support. In 2004, a group of consultants identified the need for a publication similar to the Manual for Reactor Produced Isotopes covering those isotopes that are of both current and potential interest. Consequently, 49 isotopes were identified, and 20 of these were further grouped in terms of their higher utility. It was decided to produce a report covering all the relevant information needed for the production of the above isotopes; the level of information corresponds to the extent of each isotope’s utility and the need for it. Consequently, this report covers data on nuclear decay characteristics such as half-life, mode of decay, energy and abundance, nuclear reactions and the excitation functions of the selected isotopes. The nuclear data given in this report are adapted from either the database of the IAEA and/or that of Brookhaven National Laboratory. For the most commonly used isotopes, additional data on target preparation, radiochemical processing, recovery of enriched targets and radiochemical specifications are also provided. The IAEA is grateful to the consultants who prepared this report and to the reviewers for their valuable contributions. One of the consultants, D.J. Schlyer (USA), edited the scientific content of this report. The IAEA officers responsible for this report were M.R.A. Pillai and M. Haji-Saeid of the Division of Physical and Chemical Sciences. EDITORIAL NOTE Although great care has been taken to maintain the accuracy of information contained in this publication, neither the IAEA nor its Member States assume any responsibility for consequences which may arise from its use. The use of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the IAEA. CONTENTS CHAPTER 1. PRINCIPLES OF PRODUCTION OF RADIOISOTOPES USING CYCLOTRONS . 1 1.1. INTRODUCTION. 1 1.2. CYCLOTRONS FOR RADIOISOTOPE PRODUCTION . 2 1.3. NUCLEAR REACTIONS . 4 1.3.1. Coulomb barrier . 5 1.3.2. Q value . 5 1.3.3. Nuclear reaction cross-section . 8 1.4. CALCULATION OF RADIOISOTOPE YIELD . 8 1.4.1. Saturation factor . 11 1.4.2. Nomenclature . 13 1.5. CYCLOTRON TARGETRY . 14 1.6. LABORATORY FACILITIES FOR RADIOISOTOPE PRODUCTION . 15 1.6.1. Laboratory design . 15 1.6.2. Airflow . 16 1.6.3. Radiation level gradient . 16 1.6.4. Workflow . 17 1.7. PACKAGES AND TRANSPORTATION OF RADIOISOTOPES . 18 1.8. CONCLUSION . 20 REFERENCES TO CHAPTER 1 . 20 CHAPTER 2. PHYSICAL CHARACTERISTICS AND PRODUCTION DETAILS OF ISOTOPES . 23 2.1. ACTINIUM-225 . 24 2.2. ARSENIC-73 . 28 2.3. ARSENIC-74 . 31 2.4.
Recommended publications
  • Subterranean Production of Neutrons, $^{39} $ Ar and $^{21} $ Ne: Rates

    Subterranean Production of Neutrons, $^{39} $ Ar and $^{21} $ Ne: Rates

    Subterranean production of neutrons, 39Ar and 21Ne: Rates and uncertainties Ondrejˇ Srˇ amek´ a,∗, Lauren Stevensb, William F. McDonoughb,c,∗∗, Sujoy Mukhopadhyayd, R. J. Petersone aDepartment of Geophysics, Faculty of Mathematics and Physics, Charles University, V Holeˇsoviˇck´ach 2, 18000 Praha 8, Czech Republic bDepartment of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, United States cDepartment of Geology, University of Maryland, College Park, MD 20742, United States dDepartment of Earth and Planetary Sciences, University of California Davis, Davis, CA 95616, United States eDepartment of Physics, University of Colorado Boulder, Boulder, CO 80309-0390, United States Abstract Accurate understanding of the subsurface production rate of the radionuclide 39Ar is necessary for argon dating tech- niques and noble gas geochemistry of the shallow and the deep Earth, and is also of interest to the WIMP dark matter experimental particle physics community. Our new calculations of subsurface production of neutrons, 21Ne, and 39Ar take advantage of the state-of-the-art reliable tools of nuclear physics to obtain reaction cross sections and spectra (TALYS) and to evaluate neutron propagation in rock (MCNP6). We discuss our method and results in relation to pre- vious studies and show the relative importance of various neutron, 21Ne, and 39Ar nucleogenic production channels. Uncertainty in nuclear reaction cross sections, which is the major contributor to overall calculation uncertainty, is estimated from variability in existing experimental and library data. Depending on selected rock composition, on the order of 107–1010 α particles are produced in one kilogram of rock per year (order of 1–103 kg−1 s−1); the number of produced neutrons is lower by ∼ 6 orders of magnitude, 21Ne production rate drops by an additional factor of 15–20, and another one order of magnitude or more is dropped in production of 39Ar.
  • Monitored Natural Attenuation of Inorganic Contaminants in Ground

    Monitored Natural Attenuation of Inorganic Contaminants in Ground

    Monitored Natural Attenuation of Inorganic Contaminants in Ground Water Volume 3 Assessment for Radionuclides Including Tritium, Radon, Strontium, Technetium, Uranium, Iodine, Radium, Thorium, Cesium, and Plutonium-Americium EPA/600/R-10/093 September 2010 Monitored Natural Attenuation of Inorganic Contaminants in Ground Water Volume 3 Assessment for Radionuclides Including Tritium, Radon, Strontium, Technetium, Uranium, Iodine, Radium, Thorium, Cesium, and Plutonium-Americium Edited by Robert G. Ford Land Remediation and Pollution Control Division Cincinnati, Ohio 45268 and Richard T. Wilkin Ground Water and Ecosystems Restoration Division Ada, Oklahoma 74820 Project Officer Robert G. Ford Land Remediation and Pollution Control Division Cincinnati, Ohio 45268 National Risk Management Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Cincinnati, Ohio 45268 Notice The U.S. Environmental Protection Agency through its Office of Research and Development managed portions of the technical work described here under EPA Contract No. 68-C-02-092 to Dynamac Corporation, Ada, Oklahoma (David Burden, Project Officer) through funds provided by the U.S. Environmental Protection Agency’s Office of Air and Radiation and Office of Solid Waste and Emergency Response. It has been subjected to the Agency’s peer and administrative review and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. All research projects making conclusions or recommendations based on environmental data and funded by the U.S. Environmental Protection Agency are required to participate in the Agency Quality Assurance Program. This project did not involve the collection or use of environmental data and, as such, did not require a Quality Assurance Plan.
  • Tracer Applications of Noble Gas Radionuclides in the Geosciences

    Tracer Applications of Noble Gas Radionuclides in the Geosciences

    To be published in Earth-Science Reviews Tracer Applications of Noble Gas Radionuclides in the Geosciences (August 20, 2013) Z.-T. Lua,b, P. Schlosserc,d, W.M. Smethie Jr.c, N.C. Sturchioe, T.P. Fischerf, B.M. Kennedyg, R. Purtscherth, J.P. Severinghausi, D.K. Solomonj, T. Tanhuak, R. Yokochie,l a Physics Division, Argonne National Laboratory, Argonne, Illinois, USA b Department of Physics and Enrico Fermi Institute, University of Chicago, Chicago, USA c Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA d Department of Earth and Environmental Sciences and Department of Earth and Environmental Engineering, Columbia University, New York, USA e Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL, USA f Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, USA g Center for Isotope Geochemistry, Lawrence Berkeley National Laboratory, Berkeley, USA h Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland i Scripps Institution of Oceanography, University of California, San Diego, USA j Department of Geology and Geophysics, University of Utah, Salt Lake City, USA k GEOMAR Helmholtz Center for Ocean Research Kiel, Marine Biogeochemistry, Kiel, Germany l Department of Geophysical Sciences, University of Chicago, Chicago, USA Abstract 81 85 39 Noble gas radionuclides, including Kr (t1/2 = 229,000 yr), Kr (t1/2 = 10.8 yr), and Ar (t1/2 = 269 yr), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, have enabled routine measurements of the radiokrypton isotopes, as well as the demonstration of the ability to measure 39Ar in environmental samples.
  • 4. Particle Generators/Accelerators

    4. Particle Generators/Accelerators

    Joint innovative training and teaching/ learning program in enhancing development and transfer knowledge of application of ionizing radiation in materials processing 4. Particle Generators/Accelerators Diana Adlienė Department of Physics Kaunas University of Technolog y Joint innovative training and teaching/ learning program in enhancing development and transfer knowledge of application of ionizing radiation in materials processing This project has been funded with support from the European Commission. This publication reflects the views only of the author. Polish National Agency and the Commission cannot be held responsible for any use which may be made of the information contained therein. Date: Oct. 2017 DISCLAIMER This presentation contains some information addapted from open access education and training materials provided by IAEA TABLE OF CONTENTS 1. Introduction 2. X-ray machines 3. Particle generators/accelerators 4. Types of industrial irradiators The best accelerator in the universe… INTRODUCTION • Naturally occurring radioactive sources: – Up to 5 MeV Alpha’s (helium nuclei) – Up to 3 MeV Beta particles (electrons) • Natural sources are difficult to maintain, their applications are limited: – Chemical processing: purity, messy, and expensive; – Low intensity; – Poor geometry; – Uncontrolled energies, usually very broad Artificial sources (beams) are requested! INTRODUCTION • Beams of accelerated particles can be used to produce beams of secondary particles: Photons (x-rays, gamma-rays, visible light) are generated from beams
  • Effects of Acute and Chronic Gamma Irradiation on the Cell Biology and Physiology of Rice Plants

    Effects of Acute and Chronic Gamma Irradiation on the Cell Biology and Physiology of Rice Plants

    plants Article Effects of Acute and Chronic Gamma Irradiation on the Cell Biology and Physiology of Rice Plants Hong-Il Choi 1,† , Sung Min Han 2,†, Yeong Deuk Jo 1 , Min Jeong Hong 1 , Sang Hoon Kim 1 and Jin-Baek Kim 1,* 1 Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 56212, Korea; [email protected] (H.-I.C.); [email protected] (Y.D.J.); [email protected] (M.J.H.); [email protected] (S.H.K.) 2 Division of Ecological Safety, National Institute of Ecology, Seocheon 33657, Korea; [email protected] * Correspondence: [email protected]; Tel.: +82-63-570-3313 † Both authors contributed equally to this work. Abstract: The response to gamma irradiation varies among plant species and is affected by the total irradiation dose and dose rate. In this study, we examined the immediate and ensuing responses to acute and chronic gamma irradiation in rice (Oryza sativa L.). Rice plants at the tillering stage were exposed to gamma rays for 8 h (acute irradiation) or 10 days (chronic irradiation), with a total irradiation dose of 100, 200, or 300 Gy. Plants exposed to gamma irradiation were then analyzed for DNA damage, oxidative stress indicators including free radical content and lipid peroxidation, radical scavenging, and antioxidant activity. The results showed that all stress indices increased immediately after exposure to both acute and chronic irradiation in a dose-dependent manner, and acute irradiation had a greater effect on plants than chronic irradiation. The photosynthetic efficiency and growth of plants measured at 10, 20, and 30 days post-irradiation decreased in irradiated plants, Citation: Choi, H.-I.; Han, S.M.; Jo, Y.D.; Hong, M.J.; Kim, S.H.; Kim, J.-B.
  • Effects of Gamma-Irradiation of Seed Potatoes on Numbers of Stems and Tubers

    Effects of Gamma-Irradiation of Seed Potatoes on Numbers of Stems and Tubers

    Netherlands Journal of Agricultural Science 39 (1991) 81-90 Effects of gamma-irradiation of seed potatoes on numbers of stems and tubers A. J. HAVERKORT1, D. I. LANGERAK2 & M. VAN DE WAART1 1 Centre for Agrobiological Research (CABO-DLO), P.O. Box 14, NL 6700 AA Wagenin- gen, Netherlands 2 State Institute for Quality Control of Agricultural Products (RIKILT), P.O. Box 230, NL 6700 AE Wageningen, Netherlands Received 28 november 1990; accepted 8 February 1991 Abstract In field trials with the cultivars Bintje, Jaerla and Spunta, whose seed potatoes were treated with gamma-rays from a ^Co source with doses varying from 0.5 to 27 Gy, tuber yield, har­ vest index, and number of stems and tubers were determined. A dose of 3 Gy increased the number of tubers by 30 % in Spunta in two out of three trials and by 17 % in one trial in Jaer­ la, but it did not increase number of tubers in Bintje. Doses of 9 or 10 Gy did not influence the number of tubers nor stems, and decreased harvest index. A dose of 27 Gy yielded off-type plants with reduced yield and number of tubers. Gamma-radiation affected the growth of the apex of the sprout allowing lateral buds or divisions of the affected apex to develop into stems. To achieve larger numbers of tuber-bearing stems, tubers should preferably be irra­ diated at the start of sprout growth, about 5 months before planting. Keywords: harvest index, gamma irradiation, seed potatoes Introduction Effects of different doses of gamma-rays on potato tubers have been studied exten­ sively, especially in the 1960s.
  • Atmospheric Source Terms for the Idaho Chemical Processing Plant, 1957 – 1959

    Atmospheric Source Terms for the Idaho Chemical Processing Plant, 1957 – 1959

    FINAL ATMOSPHERIC SOURCE TERMS FOR THE IDAHO CHEMICAL PROCESSING PLANT, 1957–1959 Contract No. 200-2002-00367 Task Order No. 1, Subtask 1 A final report to the Centers for Disease Control and Prevention Atlanta, Georgia 30335 SC&A, Inc. 6858 Old Dominion Drive, Suite 301 McLean, Virginia 22101 SENES Oak Ridge, Inc. 102 Donner Drive Oak Ridge, Tennessee 37830 Authors: Robert P. Wichner, SENES Oak Ridge, Inc. John-Paul Renier, SENES Oak Ridge, Inc. A. Iulian Apostoaei, SENES Oak Ridge, Inc. July 2005 ICPP Source Terms July 2005 TABLE OF CONTENTS EXECUTIVE SUMMARY .......................................................................................................ES-1 1.0 SCOPE AND APPROACH ............................................................................................. 1-1 1.1 Scope .................................................................................................................. 1-1 1.2 Approach.............................................................................................................. 1-1 1.2.1 Operational RaLa Releases ...................................................................... 1-1 1.2.2 Idaho Chemical Processing Plant Criticality Approach........................... 1-2 2.0 THE RADIOACTIVE LANTHANUM (RaLa) PROCESS ............................................ 2-1 2.1 Background .......................................................................................................... 2-1 2.1.1 Requirement ............................................................................................
  • Installation of the Cyclotron Based Clinical Neutron Therapy System in Seattle

    Installation of the Cyclotron Based Clinical Neutron Therapy System in Seattle

    Proceedings of the Tenth International Conference on Cyclotrons and their Applications, East Lansing, Michigan, USA INSTALLATION OF THE CYCLOTRON BASED CLINICAL NEUTRON THERAPY SYSTEM IN SEATTLE R. Risler, J. Eenmaa, J. Jacky, I. Kalet, and P. Wootton Medical Radiation Physics RC-08, University of Washington, Seattle ~ 98195, USA S. Lindbaeck Instrument AB Scanditronix, Uppsala, Sweden Sumnary radiation areas is via sliding shielding doors rather than a maze, mai nl y to save space. For the same reason A cyclotron facility has been built for cancer a single door is used to alternately close one or the treatment with fast neutrons. 50.5 MeV protons from a other therapy room. All power supplies and the control conventional, positive ion cyclotron are used to b0m­ computer are located on the second floor, above the bard a semi-thick Beryllium target located 150 am from maintenance area. The cooler room contains a heat the treatment site. Two treatment rooms are available, exchanger and other refrigeration equipment. Not shown one with a fixed horizontal beam and one with an iso­ in the diagram is the cooling tower located in another centric gantry capable of 360 degree rotation. In part of the building. Also not shown is the hot lab addition 33 51 MeV protons and 16.5 - 25.5 MeV now under construction an an area adjacent to the deuterons are generated for isotope production inside cyclotron vault. It will be used to process radio­ the cyclotron vault. The control computer is also used isotopes produced at a target station in the vault. to record and verify treatment parameters for indi­ vidual patients and to set up and monitor the actual radiation treatment.
  • Industrial Applications of Electron Accelerators

    Industrial Applications of Electron Accelerators

    Industrial applications of electron accelerators M.R. Cleland Ion Beam Applications, Edgewood, NY 11717, USA Abstract This paper addresses the industrial applications of electron accelerators for modifying the physical, chemical or biological properties of materials and commercial products by treatment with ionizing radiation. Many beneficial effects can be obtained with these methods, which are known as radiation processing. The earliest practical applications occurred during the 1950s, and the business of radiation processing has been expanding since that time. The most prevalent applications are the modification of many different plastic and rubber products and the sterilization of single-use medical devices. Emerging applications are the pasteurization and preservation of foods and the treatment of toxic industrial wastes. Industrial accelerators can now provide electron energies greater than 10 MeV and average beam powers as high as 700 kW. The availability of high-energy, high-power electron beams is stimulating interest in the use of X-rays (bremsstrahlung) as an alternative to gamma rays from radioactive nuclides. 1 Introduction Radiation processing can be defined as the treatment of materials and products with radiation or ionizing energy to change their physical, chemical or biological characteristics, to increase their usefulness and value, or to reduce their impact on the environment. Accelerated electrons, X-rays (bremsstrahlung) emitted by energetic electrons, and gamma rays emitted by radioactive nuclides are suitable energy sources. These are all capable of ejecting atomic electrons, which can then ionize other atoms in a cascade of collisions. So they can produce similar molecular effects. The choice of energy source is usually based on practical considerations, such as absorbed dose, dose uniformity (max/min) ratio, material thickness, density and configuration, processing rate, capital and operating costs.
  • Call Numbers

    Call Numbers

    Call numbers: It is our recommendation that libraries NOT put J, +, E, Ref, etc. in the call number field in front of the Dewey or other call number. Use the Home Location field to indicate the collection for the item. It is difficult if not impossible to sort lists if the call number fields aren’t entered systematically. Dewey Call Numbers for Non-Fiction Each library follows its own practice for how long a Dewey number they use and what letters are used for the author’s name. Some libraries use a number (Cutter number from a table) after the letters for the author’s name. Other just use letters for the author’s name. Call Numbers for Fiction For fiction, the call number is usually the author’s Last Name, First Name. (Use a comma between last and first name.) It is usually already in the call number field when you barcode. Call Numbers for Paperbacks Each library follows its own practice. Just be consistent for easier handling of the weeding lists. WCTS libraries should follow the format used by WCTS for the items processed by them for your library. Most call numbers are either the author’s name or just the first letters of the author’s last name. Please DO catalog your paperbacks so they can be shared with other libraries. Call Numbers for Magazines To get the call numbers to display in the correct order by date, the call number needs to begin with the date of the issue in a number format, followed by the issue in alphanumeric format.
  • UC Irvine UC Irvine Previously Published Works

    UC Irvine UC Irvine Previously Published Works

    UC Irvine UC Irvine Previously Published Works Title Astrophysics in 2006 Permalink https://escholarship.org/uc/item/5760h9v8 Journal Space Science Reviews, 132(1) ISSN 0038-6308 Authors Trimble, V Aschwanden, MJ Hansen, CJ Publication Date 2007-09-01 DOI 10.1007/s11214-007-9224-0 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Space Sci Rev (2007) 132: 1–182 DOI 10.1007/s11214-007-9224-0 Astrophysics in 2006 Virginia Trimble · Markus J. Aschwanden · Carl J. Hansen Received: 11 May 2007 / Accepted: 24 May 2007 / Published online: 23 October 2007 © Springer Science+Business Media B.V. 2007 Abstract The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the Universe) and others of which there are always many, like meteors and molecules, black holes and binaries. Keywords Cosmology: general · Galaxies: general · ISM: general · Stars: general · Sun: general · Planets and satellites: general · Astrobiology · Star clusters · Binary stars · Clusters of galaxies · Gamma-ray bursts · Milky Way · Earth · Active galaxies · Supernovae 1 Introduction Astrophysics in 2006 modifies a long tradition by moving to a new journal, which you hold in your (real or virtual) hands. The fifteen previous articles in the series are referenced oc- casionally as Ap91 to Ap05 below and appeared in volumes 104–118 of Publications of V.
  • Minorities and Women in Television See Little Change, While Minorities Fare Worse in Radio

    Minorities and Women in Television See Little Change, While Minorities Fare Worse in Radio

    RunningRunning inin PlacePlace Minorities and women in television see little change, while minorities fare worse in radio. By Bob Papper he latest figures from the RTNDA/Ball State Uni- Minority Population vs. Minority Broadcast Workforce versity Annual Survey show lit- 2005 2004 2000 1995 1990 tle change for minorities in tel- evision news in the past year but Minority Population in U.S. 33.2% 32.8% 30.9% 27.9% 25.9% slippage in radio news. Minority TV Workforce 21.2 21.8 21.0 17.1 17.8 TIn television, the overall minority Minority Radio Workforce 7.9 11.8 10.0 14.7 10.8 workforce remained largely un- Source for U.S. numbers: U.S. Census Bureau changed at 21.2 percent, compared with last year’s 21.8 percent. At non-Hispanic stations, the the stringent Equal Employment minority workforce in TV news is up minority workforce also remained Opportunity rules were eliminated in 3.4 percent. At the same time, the largely steady at 19.5 percent, com- 1998. minority population in the U.S. has pared with 19.8 percent a year ago. News director numbers were increased 7.3 percent. Overall, the After a jump in last year’s minority mixed, with the percentage of minor- minority workforce in TV has been at radio numbers, the percentage fell this ity TV news directors down slightly to 20 percent—plus or minus 3 per- year.The minority radio news work- 12 percent (from 12.5 percent last cent—for every year in the past 15.