Download or read book Secondary Electron Ion Source Neutron Generator written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter. The target contains occluded deuterium, tritium, or a mixture thereof.

Download or read book Characteristics of a RF Driven Ion Source for a Neutron Generator Used For Associated Particle Imaging written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent work on a prototype compact neutron generator for associated particle imaging (API). API uses alpha particles that are produced simultaneously with neutrons in the deuterium-tritium (2D(3T, n)4 alpha) fusion reaction to determine the direction of the neutrons upon exiting the reaction. This method determines the spatial position of each neutron interaction and requires the neutrons to be generated from a small spot in order to achieve high spatial resolution. The ion source for API is designed to produce a focused ion beam with a beam spot diameter of 1-mm or less on the target. We use an axial type neutron generator with a predicted neutron yield of 108 n/s for a 50 muA D/T ion beam current accelerated to 80 kV. The generator utilizes a RF planar spiral antenna at 13.56 MHz to create a highly efficient inductively-coupled plasma at the ion source. Experimental results show that beams with an atomic ion fraction of over 80percent can be obtained while utilizing only 100 watts of RF power in the ion source. A single acceleration gap with a secondary electron suppression electrode is used in the tube. Experimental results, such as the current density, atomic ion fraction, electron temperature, and electron density, from ion source testing will be discussed.

Download or read book Development of a Compact Neutron Generator to be Used For Associated Particle Imaging Utilizing a RF Driven Ion Source written by Ying Wu and published by . This book was released on 2009 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion source development plays an important role for improving and advancing the neutron generator technology used for active interrogation techniques employed by the Department of Homeland Security. Active neutron interrogation using compact neutron generators has been around since the late 1950's for use in oil well logging. However, since the September 11th, 2001 terrorists attack, much attention has been paid to the field of active neutron interrogation for detecting hidden explosives and special nuclear materials (SNM) in cargo and luggage containers through the development of effective and efficient radioactive sources and detectors. In particular, the Associated Particle Imaging (API) method for detecting and imaging explosives is of great interest New compact neutron generators will help to enhance the capabilities of existing threat detection systems and promote the development of cutting-edge detection technologies. The work performed in this thesis includes the testing of various ion source configurations and the development and characterization of an inductively coupled radio frequency (RF) ion source for use in compact neutron generators. These ion source designs have been investigated for the purpose of D-T neutron generation for explosive detection via the Associated Particle Imaging (API) technique. API makes use of the 3.5 MeV alpha particles that are produced simultaneously with the 14 MeV neutrons in the deuterium-tritium (2D(3T, n)4) fusion reaction to determine the direction of the neutrons and to reduce background noise. The Associated Particle Imaging neutron generator required a beam spot of 1-mm or less in diameter at the target in order to achieve the necessary spatial image resolution. For portable neutron generators used in API, the ion source and target cannot be water-cooled and the power deposited on the target must be low. By increasing the atomic ion fraction, the ion beam can be used more efficiently to generate neutrons, resulting in a lower beam power requirement and an increased lifetime of the alpha detector inside the acceleration column. Various source configurations, antenna design, and permanent magnet placement have been investigated so as to develop an ion source which could provide high monatomic deuterium species and high current density at relatively low RF powers (less than 200 W). In this work, an RF ion source was developed that uses an external, planar, spiral antenna at 13.56 MHz with a quartz source body and side multi-cusp magnets to generate hydrogen isotope plasmas with high mono-atomic ion species (> 80%) while consuming only 150 watts of power and operating under 10 mTorr of gas pressure. A single acceleration gap with a secondary electron suppression electrode are used in the tube. Experimental measurements of the ion source plasma parameters including ion current density, atomic ion fraction, ignition and operating pressures, electron temperature, and electron density are presented along with a discussion on the ion optics and engineering challenges. It is shown that the measured neutron yield for the developed D-D neutron generator was 2 x 105 n/s, which scales to 8 x 107 n/s for D-T operation. In addition, initial measurements of the neutron generator performance including the beam spot size, associated particle detection, and neutron tube (without pumping) operation will be discussed. Some suggestions for future improvement are also presented in this dissertation.

Download or read book Neutron Generators for Analytical Purposes written by International Atomic Energy Agency and published by IAEA Radiation Technology Repo. This book was released on 2012 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 the on-line analysis of aluminium, coal and cement. Pulsed fast thermal neutron analysis, as well as tagged and timed neutron analysis, are additional techniques which can be applied using NG. Furthermore, NG can effectively be used for elemental analysis and is also effective for analysis of hidden materials by neutron radiography. Useful guidelines for developing NG based research laboratories are also provided in this publication.

Download or read book Handbook of Fast Neutron Generators Volume I written by Julius Csikai and published by CRC Press. This book was released on 1987-09-30 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook reviews those problems and methods of science and technology where the neutrons produced in the 3H/d, N/4He, and 2H/d, n/3He reactions play the main role. This two-volume set: Discusses possible applications of these small generators as thermal neutron sources Enables suitable topics to be selected for education and training, provides a wide range of experiments with the detection of neutrons and charged particles, including the study of shielding and the generator technology itself Gives a review of important operational characteristics of neutron generators and the necessary instruments connected with these applications Provides an account of recent results of fast neutron activation analysis in various fields.

Download or read book D T Neutron Generator Development for Cancer Therapy 1980 Annual Progress Report written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the work completed during the first year of a two-year grant by NCI/HEW to investigate the feasibility of developing a D-T neutron generator for use in cancer therapy. Experiments have continued on the Target Test Facility (TTF) developed during a previous grant to investigate high-temperature metal hydrides for use as target materials. The high voltage reliability of the TTF has been improved so that 200 kV, 200 mA operation is now routine. In recent target tests, the D-D neutron production rate was measured to be> 1 x 1011/s, a rate that corresponds to a D-T neutron production rate of> 1 x 1013/s - the desired rate for use in cancer therapy. Deuterium concentration depth profiles in the target, measured during intense ion beam bombardment, show that deuterium is depleted near the surface of the target due to impurities implanted by the ion beam. Recent modifications of the duopigatron ion source to reduce secondary electron damage to the electrodes also improved the ion source efficiency by about 40%. An ultra high vacuum version of the TTF is now being constructed to determine if improved vacuum conditions will reduce ion source impurities to a sufficiently low level that the deuterium near the surface of the target is not depleted. Testing will begin in June 1980.

Download or read book Advanced Penning type Ion Source Development and Passive Beam Focusing Techniques for an Associated Particle Imaging Neutron Generator written by Amy Sy and published by . This book was released on 2013 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of accelerator-based neutron generators for non-destructive imaging and analysis in commercial and security applications is continuously under development, with improvements to available systems and combinations of available techniques revealing new capabilities for real-time elemental and isotopic analysis. The recent application of associated particle imaging (API) techniques for time- and directionally-tagged neutrons to induced fission and transmission imaging methods demonstrates such capabilities in the characterization of fissile material configurations and greatly benefits from improvements to existing neutron generator systems. Increased neutron yields and improved spatial resolution can enhance the capabilities of imaging methods utilizing the API technique. The work presented in this dissertation focused on the development of components for use within an API neutron generator with enhanced system spatial resolution. The major focus areas were the ion source development for plasma generation, and passive ion beam focusing techniques for the small ion beam widths necessary for the enhanced spatial resolution. The ion source development focused on exploring methods for improvement of Penning-type ion sources that are used in conventional API neutron generator systems, while the passive beam focusing techniques explored both ion beam collimation and ion guiding with tapered dielectric capillaries for reduced beam widths at the neutron production target.

Download or read book Neutron Generators with Size Scalability Ease of Fabrication and Multiple Ion Source Functionalities written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A neutron generator is provided with a flat, rectilinear geometry and surface mounted metallizations. This construction provides scalability and ease of fabrication, and permits multiple ion source functionalities.

Download or read book Compact Ion Source Neutron Generator written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A neutron generator includes a conductive substrate comprising a plurality of conductive nanostructures with free-standing tips and a source of an atomic species to introduce the atomic species in proximity to the free-standing tips. A target placed apart from the substrate is voltage biased relative to the substrate to ionize and accelerate the ionized atomic species toward the target. The target includes an element capable of a nuclear fusion reaction with the ionized atomic species to produce a one or more neutrons as a reaction by-product.

Download or read book Associated Particle Imaging Neutron Generator with an RF Driven Negative Ion Source written by and published by . This book was released on 2014 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Deuteron Deuteron Neutron Generators written by Cory Scott Waltz and published by . This book was released on 2016 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: A facility based on a next-generation, high-flux D-D neutron generator (HFNG) was commissioned at the University of California Berkeley. The characterization of the HFNG is presented in the following study. The current generator design produces near mono-energetic 2.45 MeV neutrons at outputs of 10^8 n/s. Calculations provided show that future conditioning at higher currents and voltages will allow for a production rate over 10^10 n/s. Characteristics that affect the operational stability include the suppression of the target-emitted back streaming electrons, target sputtering and cooling, and ion beam optics. Suppression of secondary electrons resulting from the deuterium beam striking the target was achieved via the implementation of an electrostatic shroud with a voltage offset of greater than -400 V relative to the target. Ion beam optics analysis resulted in the creation of a defocussing extraction nozzle, allowing for cooler target temperatures and a more compact design. To calculate the target temperatures, a finite difference method (FDM) solver incorporating the additional heat removal effects of subcooled boiling was developed. Validation of the energy balance results from the finite difference method calculations showed the iterative solver converged to heat removal results within about 3% of the expected value. Testing of the extraction nozzle at 1.43 mA and 100 kV determined that overheating of the target did not occur as the measured neutron flux of the generator was near predicted values. Many factors, including the target stopping power, deuterium atomic species, and target loading ratio, affect the flux distribution of the HFNG neutron generator. A detailed analysis to understand these factors effects is presented. Comparison of the calculated flux of the neutron generator using deuteron depth implantation data, neutron flux distribution data, and deuterium atomic species data matched the experimentally calculated flux determined from indium foil irradiations. An overview of experiments using the HFNG, including medical isotope cross section measurements, geochronology, delayed gamma measurements from uranium fission, and single event upset of cpu's is discussed. Future work should focus on the reduction of beam induced arcing between the shroud and the vacuum chamber. Investigation of insulator charge build-up, as well as electrical flash-over of insulators should be explored. The reduction of beam induced arcing will allow for larger beam currents and acceleration voltages, therefore increasing the neutron flux.

Download or read book A High Frequency Ion Source written by V. M. Morozov and published by . This book was released on 1955 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of an Improved Penning Ion Source for Neutron Generator Applications written by Amy Vong Sy and published by . This book was released on 2011 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Portable Accelerating Tube with Ion Source for Neutron Generator written by E. A. AB and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of a Laser Ion Source Neutron Generator written by Aleksandr Stepanovich T︠S︡ybin and published by . This book was released on 1986 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book written by Otzar hahochma and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review of Work Related to Ion Sources and Targets for Radioactive Beams at Argonne written by and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A group including many ANL Physics Division staff and ATLAS outside users has discussed the possibilities for research with radioactive ion beams and prepared a working paper entitled {open_quotes}Concept for an Advanced Exotic Beam Facility Based on ATLAS.{close_quotes} Several subgroups have been working on issues related to ion sources and targets which could be used in the production and ionization of radionuclides with high power primary beams. Present activities include: (a) setting up an ion source test stand to measure emittances and energy spreads of ISOL-type ion sources, (b) experiments to evaluate methods of containing liquid uranium for production targets, (c) experimental evaluation of geometries for the generation of secondary neutron beams for production of radionuclides, (d) setting up an ISOL-type ion source at a neutron generator facility to measure fission fragment release times and efficiencies, and (e) computer simulations of an electron-beam charge-state amplifier to increase the charge states of 1 secondary beams to 2,3 or 4. The present status of these projects and future plans are reported below.