IAEA RADIATION TECHNOLOGY REPORTS No. 1 IAEA RADIATION TECHNOLOGY REPORTS No. 1 TECHNOLOGY IAEA RADIATION This publication addresses recent developments in neutron generator (NG) technology. It presents information on compact instruments with high neutron yield to be used for neutron activation analysis (NAA) and prompt gamma neutron activation analysis in combination with high count rate spectrometers. Traditional NGs have been shown to be effective for applications including borehole logging, homeland security, nuclear medicine and on-line analysis of aluminium, coal and cement. Pulsed fast thermal neutron analysis, as well as tagged and timed neutron analysis, are additional techniques that can be applied using NG technology. NGs can be used effectively for elemental analysis and for analysis of hidden materials by neutron radiography. Useful guidelines for developing NG based research laboratories are provided in this report. Neutron Generators for Analytical Purposes INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA ISBN 978–92–0–125110–7 ISSN 2225–8833 NEUTRON GENERATORS FOR ANALYTICAL PURPOSES The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GHANA NIGERIA ALBANIA GREECE NORWAY ALGERIA GUATEMALA OMAN ANGOLA HAITI PAKISTAN ARGENTINA HOLY SEE PALAU ARMENIA HONDURAS PANAMA AUSTRALIA HUNGARY PARAGUAY ICELAND AUSTRIA PERU AZERBAIJAN INDIA PHILIPPINES BAHRAIN INDONESIA POLAND BANGLADESH IRAN, ISLAMIC REPUBLIC OF PORTUGAL BELARUS IRAQ QATAR BELGIUM IRELAND REPUBLIC OF MOLDOVA BELIZE ISRAEL BENIN ITALY ROMANIA BOLIVIA JAMAICA RUSSIAN FEDERATION BOSNIA AND HERZEGOVINA JAPAN SAUDI ARABIA BOTSWANA JORDAN SENEGAL BRAZIL KAZAKHSTAN SERBIA BULGARIA KENYA SEYCHELLES BURKINA FASO KOREA, REPUBLIC OF SIERRA LEONE BURUNDI KUWAIT SINGAPORE CAMBODIA KYRGYZSTAN SLOVAKIA CAMEROON LAO PEOPLES DEMOCRATIC SLOVENIA REPUBLIC CANADA SOUTH AFRICA LATVIA CENTRAL AFRICAN SPAIN REPUBLIC LEBANON SRI LANKA CHAD LESOTHO SUDAN CHILE LIBERIA SWEDEN CHINA LIBYA SWITZERLAND COLOMBIA LIECHTENSTEIN SYRIAN ARAB REPUBLIC CONGO LITHUANIA COSTA RICA LUXEMBOURG TAJIKISTAN CÔTE DIVOIRE MADAGASCAR THAILAND CROATIA MALAWI THE FORMER YUGOSLAV REPUBLIC OF MACEDONIA CUBA MALAYSIA CYPRUS MALI TUNISIA CZECH REPUBLIC MALTA TURKEY DEMOCRATIC REPUBLIC MARSHALL ISLANDS UGANDA OF THE CONGO MAURITANIA UKRAINE DENMARK MAURITIUS UNITED ARAB EMIRATES DOMINICA MEXICO UNITED KINGDOM OF DOMINICAN REPUBLIC MONACO GREAT BRITAIN AND ECUADOR MONGOLIA NORTHERN IRELAND EGYPT MONTENEGRO UNITED REPUBLIC OF TANZANIA EL SALVADOR MOROCCO ERITREA MOZAMBIQUE UNITED STATES OF AMERICA ESTONIA MYANMAR URUGUAY ETHIOPIA NAMIBIA UZBEKISTAN FINLAND NEPAL VENEZUELA FRANCE NETHERLANDS VIETNAM GABON NEW ZEALAND YEMEN GEORGIA NICARAGUA ZAMBIA GERMANY NIGER 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, IAEA Radiation Technology Reports Series No. 1 NEUTRON GENERATORS FOR ANALYTICAL PURPOSES INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 2012 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: Marketing and Sales Unit, Publishing Section International Atomic Energy Agency Vienna International Centre PO Box 100 1400 Vienna, Austria fax: +43 1 2600 29302 tel.: +43 1 2600 22417 email: [email protected] http://www.iaea.org/books For further information on this publication, please contact: Physics Section International Atomic Energy Agency Vienna International Centre PO Box 100 1400 Vienna, Austria email: [email protected] IAEA Library Cataloguing in Publication Data Neutron generators for analytical purposes. – Vienna : International Atomic Energy Agency, 2012. p. ; 30 cm. – (IAEA radiation technology reports series, ISSN 2225-8833 ; no. 1) STI/PUB/1535 ISBN 978-92-0-125110-7 Includes bibliographical references. 1. Neutron sources. 2. Nuclear activation analysis. 3. Radiography. I. International Atomic Energy Agency II. Series. IAEAL 12-00724 FOREWORD The IAEA’s project on strengthening capabilities for detection of explosives and illicit materials and for compositional analysis helps Member States to find appropriate applications of specific nuclear techniques. Neutron based techniques are excellent tools for characterization of a very broad range of materials. The same technique with different analytical power can be applied for detection of elements in extremely low quantities in illicit materials hidden in large volume, or be utilized as qualitative and quantitative multi-element analysis of major, minor and trace elements in samples from almost every conceivable field of scientific or technical interest. Prompt gamma neutron activation analysis (PGNAA) has been used for prospecting of minerals, for process control in the cement industry and in coal fired power plants, for the detection of explosives at airports and for demining of land, for in vivo measurement of various elements in animal and human bodies, for the determination of hydrogen in metals, and various elements in biological and environmental materials. The equipment needed for PGNAA is virtually identical to conventional neutron activation analysis (NAA). Thus, all research facilities where INAA is carried out could potentially install PGNAA if a beam line from a research reactor or any other neutron source is made available for the irradiation of samples. New generations of neutron generators (NGs) are available and offer increased possibilities for any NAA applications especially towards in situ measurement. The capability of assaying elemental compositions of complex objects non-destructively using fast neutron probes has been demonstrated in a number of scenarios over the past decade. In a broader sense of the term ‘radiography’, one can state that such devices are capable of producing elemental images of medium to large sized objects (even in three dimensions) with adequate spatial resolution for other specific applications such as screening air cargo or unattended luggage, as well as quality control in the textile industry. Current developments of new and powerful NGs make them attractive as cost effective alternatives to isotopic neutron sources for irradiation purposes. In particular, new DD NGs (Deuterium-Deuterium Neutron Generators) seem to overcome the constraints of deuterium/tritium technology with respect to tritium handling and the limited lifetime of sealed tubes. The use of NGs for irradiation of samples for analytical purposes has been explored in the past, and thus the use of these devices for teaching purposes is feasible and might also be attractive for some industrial and research applications. Following the publication by the IAEA of Isotopic Neutron Sources for Neutron Activation Analysis (IAEA-TECDOC-465) in 1988 and Use of Accelerator Based Neutron Sources (IAEA-TECDOC-1153) in 2000, it was felt that an updated report should be published on the Use of Neutron Generators for Analytical Purposes with the emphasis on describing the new generation of generators and evaluating their value for NAA and PGNAA in a special design study. This publication is the result of extensive work carried out by the participants of an IAEA coordinated research project on ‘New Applications of PGNAA’ (2003–2005) and inputs from Technical Meetings on ‘Neutron Generators for Analytical Purposes’ (2007) and ‘Fast-Neutron Resonance Radiography Applications’ (2009). The IAEA officer responsible for this publication was F. Mulhauser, of the Division of Physical and Chemical Sciences. EDITORIAL NOTE 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. INTRODUCTION .............................................................................................. 1 1.1. Nuclear analytical techniques ............................................................................. 1 1.2. Alternatives to research reactors ......................................................................... 1 1.3. New developments in neutron generators .......................................................... 2 1.4. Applications of neutron generators ..................................................................... 2 CHAPTER 2. THE HISTORICAL DEVELOPMENT OF NEUTRON GENERATORS ........ 3 2.1. Introduction .......................................................................................................