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Sample records for accelerator driven neutron

  1. Neutronic parameters characterizing accelerator driven system (ADS)

    An hybrid system is a reactor where an external source of spallation neutrons is supplied to a subcritical multiplying medium. The neutronic parameters characterising such a system include, in addition to the multiplication factor which measures the sub-criticality level, another physics parameter measuring the 'importance' of the external source. The aim of this thesis is, on the one hand, to investigate basic neutronic phenomena taking place in fast sub- critical media in either steady-state or transient operation, and, on the other hand, to assess the performance of the ERANOS neutronic code package applied to the analysis of such systems. To this aim, the first part of the work is focused on the MUSE program and in particular the MUSE3 experiment, which consists of different sub-critical configurations driven by a 14-MeV neutron source. This study has been pursued in two directions : the first one was the interpretation of the calculation-experiment (C-E) discrepancies which lead to the development of original calculation methods for sensitivity studies ; the second one was the experimental analysis which allowed an extensive neutronic characterization of the sub-critical system. A correlation between the external source importance and some directly measurable parameters (i.e. fission rate) was derived. The second part of the thesis addresses representativity issues between an experimental facility and an actual power reactor. Important conclusions have been drawn with regard to the operation of an ADS. Finally, representativity studies lead to the recommendation that a demonstration reactor should be built before an industrial plant is constructed. (author)

  2. Superpower linear proton accelerator for neutron generator and accelerator-driven system

    The perspectives of development of superpower linear proton accelerators for high-intensive neutron generators and accelerator-driven systems are discussed. The main technical characteristics of the projects on neutron generators based on linear accelerators are presented. These projects are developed in USA, Japan, Italy and Russia. The RFQ structures are used in all projects for the initial acceleration of protons up to 5-7 MeV. The different modifications of drift tubes are applied for acceleration up to 100 MeV. The main acceleration (up to 1 GeV) is supposed to perform in superconducting resonators

  3. Accelerator driven systems (ADS): A principal neutronics and transmutation potential

    An accelerator-based system using a beam of high energy protons to produce supplementary neutrons as a result of spallation processes in a target is investigated. The spallation neutrons are successively used to feed a subcritical blanket where they create a neutron surplus available for incineration of those long-lived toxic nuclei which require neutrons (long-lived fission products and minor actinides), and enhance the deterministic safety features for reactivity-type of accidents

  4. Accelerator-driven neutron sources for materials research

    Particle accelerators are important tools for materials research and production. Advances in high-intensity linear accelerator technology make it possible to consider enhanced neutron sources for fusion material studies or as a source of spallation neutrons. Energy variability, uniformity of target dose distribution, target bombardment from multiple directions, time-scheduled dose patterns, and other features can be provided, opening new experimental opportunities. New designs have also been used to ensure hands-on maintenance on the accelerator in these factory-type facilities. Designs suitable for proposals such as the Japanese Energy-Selective Intense Neutron Source, and the international Fusion Materials Irradiation Facility are discussed

  5. LANL sunnyside experiment: Study of neutron production in accelerator-driven targets

    Measurements have been made of the neutron production in prototypic targets for accelerator driven systems. Studies were conducted on four target assemblies containing lead, lithium, tungsten, and a thorium-salt mixture. Integral data on total neutron production were obtained as well as more differential data on neutron leakage and neutron flux profiles in the blanket/moderator region. Data analysis on total neutron production is complete and shows excellent agreement with calculations using the LAHET/MCNP code system

  6. Simulation and optimization for a 30-MeV electron accelerator driven neutron source

    A neutron source driven by electron accelerator is proposed in Shanghai Institute of Applied Physics (SINAP). The facility is planned for the study of nuclear data in Thorium-Uranium cycling system, and for material research. A detailed simulation of the neutron source is performed for the program to get the neutron generation maximum economically. Several parameters of the facility, which affect the neutron yield and the neutron escape from outer surface of the target, are analyzed respectively. Besides, the yielding neutron spectrum and the escaping neutron angular distribution are calculated and discussed. (authors)

  7. Beamed neutron emission driven by laser accelerated light ions

    Kar, S; Ahmed, H; Alejo, A; Robinson, A P L; Cerchez, M; Clarke, R; Doria, D; Dorkings, S; Fernandez, J; Mirfyazi, S R; McKenna, P; Naughton, K; Neely, D; Norreys, P; Peth, C; Powell, H; Ruiz, J A; Swain, J; Willi, O; Borghesi, M

    2015-01-01

    We report on the experimental observation of beam-like neutron emission with peak flux of the order of 10^9 n/sr, from light nuclei reactions in a pitcher-catcher scenario, by employing MeV ions driven by high power laser. The spatial profile of the neutron beam, fully captured for the first time by employing a CR39 nuclear track detector, shows a FWHM divergence angle of 70 degrees, with a peak flux nearly an order of magnitude higher than the isotropic component elsewhere. The observed beamed flux of neutrons is highly favourable for a wide range of applications, and indeed for further transport and moderation to thermal energies. A systematic study employing various combinations of pitcher-catcher materials indicates the dominant reactions being d(p, n+p)^1H and d(d,n)^3He. Albeit insufficient cross-section data are available for modelling, the observed anisotropy in the neutrons' spatial and spectral profiles are most likely related to the directionality and high energy of the projectile ions.

  8. Accelerator driven reactors, - the significance of the energy distribution of spallation neutrons on the neutron statistics

    In order to make correct predictions of the second moment of statistical nuclear variables, such as the number of fissions and the number of thermalized neutrons, the dependence of the energy distribution of the source particles on their number should be considered. It has been pointed out recently that neglecting this number dependence in accelerator driven systems might result in bad estimates of the second moment, and this paper contains qualitative and quantitative estimates of the size of these efforts. We walk towards the requested results in two steps. First, models of the number dependent energy distributions of the neutrons that are ejected in the spallation reactions are constructed, both by simple assumptions and by extracting energy distributions of spallation neutrons from a high-energy particle transport code. Then, the second moment of nuclear variables in a sub-critical reactor, into which spallation neutrons are injected, is calculated. The results from second moment calculations using number dependent energy distributions for the source neutrons are compared to those where only the average energy distribution is used. Two physical models are employed to simulate the neutron transport in the reactor. One is analytical, treating only slowing down of neutrons by elastic scattering in the core material. For this model, equations are written down and solved for the second moment of thermalized neutrons that include the distribution of energy of the spallation neutrons. The other model utilizes Monte Carlo methods for tracking the source neutrons as they travel inside the reactor material. Fast and thermal fission reactions are considered, as well as neutron capture and elastic scattering, and the second moment of the number of fissions, the number of neutrons that leaked out of the system, etc. are calculated. Both models use a cylindrical core with a homogenous mixture of core material. Our results indicate that the number dependence of the energy

  9. Beamed neutron emission driven by laser accelerated light ions

    Kar, S.; Green, A.; Ahmed, H.; Alejo, A.; Robinson, A. P. L.; Cerchez, M.; Clarke, R.; Doria, D.; Dorkings, S.; Fernandez, J.; Mirfayzi, S. R.; McKenna, P.; Naughton, K.; Neely, D.; Norreys, P.; Peth, C.; Powell, H.; Ruiz, J. A.; Swain, J.; Willi, O.; Borghesi, M.

    2016-05-01

    Highly anisotropic, beam-like neutron emission with peak flux of the order of 109 n/sr was obtained from light nuclei reactions in a pitcher–catcher scenario, by employing MeV ions driven by a sub-petawatt laser. The spatial profile of the neutron beam, fully captured for the first time by employing a CR39 nuclear track detector, shows a FWHM divergence angle of ∼ 70^\\circ , with a peak flux nearly an order of magnitude higher than the isotropic component elsewhere. The observed beamed flux of neutrons is highly favourable for a wide range of applications, and indeed for further transport and moderation to thermal energies. A systematic study employing various combinations of pitcher–catcher materials indicates the dominant reactions being d(p, n+p)1H and d(d,n)3He. Albeit insufficient cross-section data are available for modelling, the observed anisotropy in the neutrons’ spatial and spectral profiles is most likely related to the directionality and high energy of the projectile ions.

  10. Benchmarking shielding simulations for an accelerator-driven spallation neutron source

    Cherkashyna, Nataliia; DiJulio, Douglas D.; Panzner, Tobias; Rantsiou, Emmanouela; Filges, Uwe; Ehlers, Georg; Bentley, Phillip M.

    2015-01-01

    The shielding at an accelerator-driven spallation neutron facility plays a critical role in the performance of the neutron scattering instruments, the overall safety, and the total cost of the facility. Accurate simulation of shielding components is thus key for the design of upcoming facilities, such as the European Spallation Source (ESS), currently in construction in Lund, Sweden. In this paper, we present a comparative study between the measured and the simulated neutron background at the...

  11. Preliminary neutronics design and analysis for accelerator driven subcritical tritium production reactor ADS-T

    In this paper, by using self-developed multi-functional 4D neutronics simulation system VisualBUS4.2 and hybrid evaluated nuclear data library HENDL3.0, sensitivity analysis on spallation neutron energy, abundance of 6Li in tritium breeding material, structural steel, initial keff, neutron energy spectrum as well as the placement of tritium production assembly was performed for lead-alloy cooled accelerator driven subcritical nuclear waste transmutation and tritium production reactor ADS-T (ADS- Tritium). Finally, preliminary neutronics options of ADS-T were given, an attractive tritium production pathway was provided. (authors)

  12. Physical aspects of neutron generation in the target of an accelerator driven system

    In order to choose the optimal target parameters in the accelerator-driven systems, some nuclear physics aspects of target processes should be investigated. The spallation, fragmentation and fission cross sections, the yields of residual nuclei and neutrons for massive targets and the simulation of hadron-nucleus interaction at intermediate energies are discussed

  13. BRAHMMA: A compact experimental accelerator driven subcritical facility using D-T/D-D neutron source

    Highlights: • Design of compact zero-power subcritical assembly BRAHMMA is presented. • One of the unique features is the use of beryllium oxide as reflector. • Modular subcritical core which can be modified for different fuel combination. • Preliminary results of reactivity measurement using PNS technique reported. - Abstract: A zero-power, sub-critical assembly BRAHMMA driven by a D-T/D-D neutron generator has been designed and commissioned at Bhabha Atomic Research Centre, India. This facility has been conceived for investigating the static and dynamic neutronics properties of accelerator driven sub-critical systems. This paper describes the design details of the system. Preliminary results of flux measurements and reactivity measurements using pulsed neutron source techniques have also been presented. This system has the advantage of being modular in design which enables its keff values to be changed depending upon type of fuel being used and it is first in the series of subcritical assemblies being designed

  14. Neutronic and burnup studies of accelerator-driven systems dedicated to nuclear waste transmutation

    Tucek, Kamil

    2004-01-01

    Partitioning and transmutation of plutonium, americium, and curium is inevitable if the radiotoxic inventory of spent nuclear fuel is to be reduced by more than a factor of 100. But, admixing minor actinides into the fuel severely degrades system safety parameters, particularly coolant void reactivity, Doppler effect, and (effective) delayed neutron fractions. The incineration process is therefore envisioned to be carried out in dedicated, accelerator-driven sub-critical reactors (ADS). Howev...

  15. MCNPX simulations of fast neutron diagnostics for accelerator-driven systems

    In accelerator-driven systems, the neutron spectrum will extend all the way up to the incident beam energy, i.e., several hundred MeV or even up to GeV energies. The high neutron energy allows novel diagnostics with a set of measurement techniques that can be used in a sub-critical reactor environment. Such measurements are primarily connected to system safety and validation. This report shows that in-core fast-neutron diagnostics can be employed to monitor changes in the position of incidence of the primary proton beam onto the neutron production target. It has also been shown that fast neutrons can be used to detect temperature-dependent density changes in a liquid lead-bismuth target. Fast neutrons can escape the system via the beam pipe for the incident proton beam. Out-of-core monitoring of these so called back-streaming neutrons could potentially be used to monitor beam changes if the target has a suitable shape. Moreover, diagnostics of back-streaming neutrons might be used for validation of the system design

  16. Calculation of the neutron importance and weighted neutron generation time using MCNIC method in accelerator driven subcritical reactors

    Highlights: • All reactor kinetic parameters are importance weighted quantities. • MCNIC method has been developed for calculating neutron importance in ADSRs. • Mean generation time has been calculated in spallation driven systems. -- Abstract: The difference between non-weighted neutron generation time (Λ) and the weighted one (Λ†) can be quite significant depending on the type of the system. In the present work, we will focus on developing MCNIC method for calculation of the neutron importance (Φ†) and importance weighted neutron generation time (Λ†) in accelerator driven systems (ADS). Two hypothetic bare and graphite reflected spallation source driven system have been considered as illustrative examples for this means. The results of this method have been compared with those obtained by MCNPX code. According to the results, the relative difference between Λ and Λ† is within 36% and 24,840% in bare and reflected illustrative examples respectively. The difference is quite significant in reflected systems and increases with reflector thickness. In Conclusion, this method may be used for better estimation of kinetic parameters rather than the MCNPX code because of using neutron importance function

  17. High-energy in-beam neutron measurements of metal-based shielding for accelerator-driven spallation neutron sources

    DiJulio, D. D.; Cooper-Jensen, C. P.; Björgvinsdóttir, H.; Kokai, Z.; Bentley, P. M.

    2016-05-01

    Metal-based shielding plays an important role in the attenuation of harmful and unwanted radiation at an accelerator-driven spallation neutron source. At the European Spallation Source, currently under construction in Lund, Sweden, metal-based materials are planned to be used extensively as neutron guide substrates in addition to other shielding structures around neutron guides. The usage of metal-based materials in the vicinity of neutron guides however requires careful consideration in order to minimize potential background effects in a neutron instrument at the facility. Therefore, we have carried out a combined study involving high-energy neutron measurements and Monte Carlo simulations of metal-based shielding, both to validate the simulation methodology and also to investigate the benefits and drawbacks of different metal-based solutions. The measurements were carried out at The Svedberg Laboratory in Uppsala, Sweden, using a 174.1 MeV neutron beam and various thicknesses of aluminum-, iron-, and copper-based shielding blocks. The results were compared to geant4 simulations and revealed excellent agreement. Our combined study highlights the particular situations where one type of metal-based solution may be preferred over another.

  18. Benchmarking shielding simulations for an accelerator-driven spallation neutron source

    Cherkashyna, Nataliia; DiJulio, Douglas D.; Panzner, Tobias; Rantsiou, Emmanouela; Filges, Uwe; Ehlers, Georg; Bentley, Phillip M.

    2015-08-01

    The shielding at an accelerator-driven spallation neutron facility plays a critical role in the performance of the neutron scattering instruments, the overall safety, and the total cost of the facility. Accurate simulation of shielding components is thus key for the design of upcoming facilities, such as the European Spallation Source (ESS), currently in construction in Lund, Sweden. In this paper, we present a comparative study between the measured and the simulated neutron background at the Swiss Spallation Neutron Source (SINQ), at the Paul Scherrer Institute (PSI), Villigen, Switzerland. The measurements were carried out at several positions along the SINQ monolith wall with the neutron dosimeter WENDI-2, which has a well-characterized response up to 5 GeV. The simulations were performed using the Monte-Carlo radiation transport code geant4, and include a complete transport from the proton beam to the measurement locations in a single calculation. An agreement between measurements and simulations is about a factor of 2 for the points where the measured radiation dose is above the background level, which is a satisfactory result for such simulations spanning many energy regimes, different physics processes and transport through several meters of shielding materials. The neutrons contributing to the radiation field emanating from the monolith were confirmed to originate from neutrons with energies above 1 MeV in the target region. The current work validates geant4 as being well suited for deep-shielding calculations at accelerator-based spallation sources. We also extrapolate what the simulated flux levels might imply for short (several tens of meters) instruments at ESS.

  19. Neutron data for accelerator-driven transmutation technologies. Annual Report 2002/2003

    Blomgren, J.; Hildebrand, A.; Mermod, P.; Olsson, N.; Pomp, S.; Oesterlund, M. [Uppsala Univ. (Sweden). Dept. for Neutron Research

    2003-08-01

    The project NATT, Neutron data for Accelerator-driven Transmutation Technology, is performed within the nuclear reactions group of the Department for neutron research, Uppsala university. The activities of the group is directed towards experimental studies of nuclear reaction probabilities of importance for various applications, like transmutation of nuclear waste, biomedical effects and electronics reliability. The experimental work is primarily undertaken at the The Svedberg Laboratory (TSL) in Uppsala, where the group has previously developed two world-unique instruments, MEDLEY and SCANDAL. Highlights from the past year: Analysis and documentation has been finalized of previously performed measurements of elastic neutron scattering from carbon and lead at 96 MeV. The precision in the results surpasses all previous data by at least an order of magnitude. These measurements represent the highest energy in neutron scattering where the ground state has been resolved. The results show that all previous theory work has underestimated the probability for neutron scattering at the present energy by 0-30 %. A new method for measurements of absolute probabilities for neutron-induced nuclear reactions with experimental techniques only has been developed. Previously, only two such methods have been known. One student has reached his PhD exam. Two PhD students have been accepted. TSL has decided to build a new neutron beam facility with significantly improved performance for these, and similar, activities. A new instrument for measurements of inelastic neutron scattering has been built, tested and found to meet the specifications. This work has been performed in collaboration with two French research groups from Caen and Nantes. The instrument is intended to be used for a series of experiments during the coming years. Previous work by the group on nuclear data for assessment of electronics reliability has lead to a new industry standard in the USA.

  20. Neutron data for accelerator-driven transmutation technologies. Annual Report 2002/2003

    The project NATT, Neutron data for Accelerator-driven Transmutation Technology, is performed within the nuclear reactions group of the Department for neutron research, Uppsala university. The activities of the group is directed towards experimental studies of nuclear reaction probabilities of importance for various applications, like transmutation of nuclear waste, biomedical effects and electronics reliability. The experimental work is primarily undertaken at the The Svedberg Laboratory (TSL) in Uppsala, where the group has previously developed two world-unique instruments, MEDLEY and SCANDAL. Highlights from the past year: Analysis and documentation has been finalized of previously performed measurements of elastic neutron scattering from carbon and lead at 96 MeV. The precision in the results surpasses all previous data by at least an order of magnitude. These measurements represent the highest energy in neutron scattering where the ground state has been resolved. The results show that all previous theory work has underestimated the probability for neutron scattering at the present energy by 0-30 %. A new method for measurements of absolute probabilities for neutron-induced nuclear reactions with experimental techniques only has been developed. Previously, only two such methods have been known. One student has reached his PhD exam. Two PhD students have been accepted. TSL has decided to build a new neutron beam facility with significantly improved performance for these, and similar, activities. A new instrument for measurements of inelastic neutron scattering has been built, tested and found to meet the specifications. This work has been performed in collaboration with two French research groups from Caen and Nantes. The instrument is intended to be used for a series of experiments during the coming years. Previous work by the group on nuclear data for assessment of electronics reliability has lead to a new industry standard in the USA

  1. A neutron booster for spallation sources—application to accelerator driven systems and isotope production

    Galy, J.; Magill, J.; Van Dam, H.; Valko, J.

    2002-06-01

    One can design a critical system with fissile material in the form of a thin layer on the inner surface of a cylindrical neutron moderator such as graphite or beryllium. Recently, we have investigated the properties of critical and near critical systems based on the use of thin actinide layers of uranium, plutonium and americium. The thickness of the required fissile layer depends on the type of fissile material, its concentration in the layer and on the geometrical arrangement, but is typically in the μm-mm range. The resulting total mass of fissile material can be as low as 100 g. Thin fissile layers have a variety of applications in nuclear technology—for example in the design neutron amplifiers for medical applications and "fast" islands in thermal reactors for waste incineration. In the present paper, we investigate the properties of a neutron booster unit for spallation sources and isotope production. In those applications a layer of fissile material surrounds the spallation source. Such a module could be developed for spallation targets foreseen in the MYRRHA (L. Van Den Durpel, H. Aı̈t Abderrahim, P. D'hondt, G. Minsart, J.L. Bellefontaine, S. Bodart, B. Ponsard, F. Vermeersch, W. Wacquier. A prototype accelerator driven system in Belgium: the Myrrha project, Technical Committee Meeting on Feasibility and Motivation for Hybrid concepts for Nuclear Energy generation and Transmutation, Madrid, Spain, September 17-19, 1997 [1]). or MEGAPIE (M. Salvatores, G.S. Bauer, G. Heusener. The MEGAPIE initiative: executive outline and status as per November 1999, MPO-1-GB-6/0_GB, 1999 [2]) projects. With a neutron multiplication factor of the booster unit in the range 10-20 (i.e. with a keff of 0.9-0.95), considerably less powerful accelerators would be required to obtain the desired neutron flux. Instead of the powerful accelerators with proton energies of 1 GeV and currents of 10 mA foreseen for accelerator driven systems, similar neutron fluxes can be obtained

  2. Neutronic Design of an Accelerator Driven Sub-Critical Research Reactor

    Conceptual design of an accelerator driven sub-critical research reactor (ADSRR), as a new project in the Vinca Institute of Nuclear Sciences, is suggested for support to the Ministry of science, technologies and development of Republic Serbia, Yugoslavia. This paper show initial results of neutronic analyses of the proposed ADSRR carried out by Monte Carlo based MCNP and SHIELD codes. According to the proposal, the ADSRR would be constructed, in a later phase, at high-energy channel H5B of the VINCY cyclotron of the TESLA Accelerator Installation, that is under completion in the Vinca Institute. The fuel elements of 80%-enriched uranium dioxide dispersed in aluminium matrix, available in the Vinca Institute, are proposed for the ADSRR core design. The HEU fuel elements are placed in aluminium tubes filled by the 'primary moderator' - light water. These 'fuel tubes' are placed in a square lattice within lead matrix in a stainless steel tank. The lead is used as a 'secondary moderator' in the core and as the axial and radial reflector. Such design of the ADSRR shows that this small low neutron flux system can be used as an experimental 'demonstration' ADS with some neutron characteristics similar to proposed well-known lead moderated and cooled power sub-critical ADS with intermediate or fast neutron spectrum. The proposed experimental ADSRR, beside usage as a valuable research machine in reactor and neutron physics, will contribute to following and developing new nuclear technologies in the country, useful for eventual nuclear power option and nuclear waste incineration in future. (author)

  3. Neutron data for accelerator-driven transmutation technologies. Annual Report 2003/2004

    The project NATT, Neutron data for Accelerator-driven Transmutation Technology, is performed within the nuclear reactions group of the Dept. of Neutron Research, Uppsala univ. The activities of the group are directed towards experimental studies of nuclear reaction probabilities of importance for various applications, like transmutation of nuclear waste, biomedical effects and electronics reliability. The experimental work is primarily undertaken at the The Svedberg Laboratory (TSL) in Uppsala, where the group has previously developed two world-unique instruments, MEDLEY and SCANDAL. Highlights from the past year: Analysis and documentation has been finalized of previously performed measurements of elastic neutron scattering from hydrogen at 96 MeV. The results corroborate the normalization of previously obtained data at TSL, which have been under debate. This is of importance since this reaction serves as reference for many other measurements. Compelling evidence of the existence of three-body forces in nuclei has been obtained. Within the project, one PhD exam and one licentiate exam has been awarded. One PhD exam and one licentiate exam has been awarded for work closely related to the project. A new neutron beam facility with significantly improved performance has been built and commissioned at TSL

  4. Neutron data for accelerator-driven transmutation technologies. Annual Report 2003/2004

    Blomgren, J.; Hildebrand, A.; Nilsson, L.; Mermod, P.; Olsson, N.; Pomp, S.; Oesterlund, M. [Uppsala Univ. (Sweden). Dept. for Neutron Research

    2004-08-01

    The project NATT, Neutron data for Accelerator-driven Transmutation Technology, is performed within the nuclear reactions group of the Dept. of Neutron Research, Uppsala univ. The activities of the group are directed towards experimental studies of nuclear reaction probabilities of importance for various applications, like transmutation of nuclear waste, biomedical effects and electronics reliability. The experimental work is primarily undertaken at the The Svedberg Laboratory (TSL) in Uppsala, where the group has previously developed two world-unique instruments, MEDLEY and SCANDAL. Highlights from the past year: Analysis and documentation has been finalized of previously performed measurements of elastic neutron scattering from hydrogen at 96 MeV. The results corroborate the normalization of previously obtained data at TSL, which have been under debate. This is of importance since this reaction serves as reference for many other measurements. Compelling evidence of the existence of three-body forces in nuclei has been obtained. Within the project, one PhD exam and one licentiate exam has been awarded. One PhD exam and one licentiate exam has been awarded for work closely related to the project. A new neutron beam facility with significantly improved performance has been built and commissioned at TSL.

  5. Preliminary neutronics design analysis on accelerator driven subcritical reactor for nuclear waste transmutation

    By taking minor actinides (MA) transmutation performance as evaluation index, preliminary neutronics design analyses were performed on ADS-NWT which is a lead-alloy cooled accelerator driven subcritical reactor for nuclear waste transmutation. In the specific design, liquid lead-bismuth eutectic (LBE) and transuranic metallic dispersion fuel were used as coolant and a fuel of ADS-NWT, respectively. The neutronics calculations and analyses were performed by using CAD-based multi-functional 4D neutronics and radiation simulation system named VisualBUS and the nuclear data library HENDL (Hybrid Evaluated Nuclear Data Library). The preliminary results showed that based on specific deign of MA/Pu volume ratio of 7 : 3, the transmutation rate of MA was approximately 650 kg/a, the high thermal reactor power output was ∼1000 MW when energy self-sustaining was satisfied and relatively deep subcriticality and negative reactivity coefficients made sure of good inherent safety of ADS-NWT. (authors)

  6. Estimation for effect of JENDL-3.3 on neutronics characteristics of accelerator-driven system

    The latest version of Japanese Evaluated Nuclear Data Library (JENDL-3.3) was released in last year. Primary purpose of this study was to estimate an effect of a revision of nuclear data library on neutronics characteristics of accelerator-driven subcritical system (ADS). The burnup calculations using both JENDL-3.3 and JENDL-3.2 were performed for JAERI proposed ADS. The detailed contribution of each nuclide and reaction on the difference of the calculation results, such as effective multiplication factor and burnup swing, were investigated. Moreover, to validate the nuclear data of actinides, the burnup analysis for the actinides samples irradiated at the Dounreay Prototype Fast Reactor were carried out. (author)

  7. Laser-driven x-ray and neutron source development for industrial applications of plasma accelerators

    Brenner, C. M.; Mirfayzi, S. R.; Rusby, D. R.; Armstrong, C.; Alejo, A.; Wilson, L. A.; Clarke, R.; Ahmed, H.; Butler, N. M. H.; Haddock, D.; Higginson, A.; McClymont, A.; Murphy, C.; Notley, M.; Oliver, P.; Allott, R.; Hernandez-Gomez, C.; Kar, S.; McKenna, P.; Neely, D.

    2016-01-01

    Pulsed beams of energetic x-rays and neutrons from intense laser interactions with solid foils are promising for applications where bright, small emission area sources, capable of multi-modal delivery are ideal. Possible end users of laser-driven multi-modal sources are those requiring advanced non-destructive inspection techniques in industry sectors of high value commerce such as aerospace, nuclear and advanced manufacturing. We report on experimental work that demonstrates multi-modal operation of high power laser-solid interactions for neutron and x-ray beam generation. Measurements and Monte Carlo radiation transport simulations show that neutron yield is increased by a factor ~2 when a 1 mm copper foil is placed behind a 2 mm lithium foil, compared to using a 2 cm block of lithium only. We explore x-ray generation with a 10 picosecond drive pulse in order to tailor the spectral content for radiography with medium density alloy metals. The impact of using  >1 ps pulse duration on laser-accelerated electron beam generation and transport is discussed alongside the optimisation of subsequent bremsstrahlung emission in thin, high atomic number target foils. X-ray spectra are deconvolved from spectrometer measurements and simulation data generated using the GEANT4 Monte Carlo code. We also demonstrate the unique capability of laser-driven x-rays in being able to deliver single pulse high spatial resolution projection imaging of thick metallic objects. Active detector radiographic imaging of industrially relevant sample objects with a 10 ps drive pulse is presented for the first time, demonstrating that features of 200 μm size are resolved when projected at high magnification.

  8. Development opportunities for small and medium scale accelerator driven neutron sources. Proceedings of a technical meeting

    Neutron applications in the life sciences will be a rapidly growing research area in the near future, as neutrons can provide unique information on the reaction dynamics of complex biomolecular systems, complementing other analytical techniques such as electron microscopy, X rays and nuclear magnetic resonance. Small and medium power spallation neutron sources will become more important, as many small neutron producing research reactors are being phased out. Recent developments in accelerator technology have made it possible to produce useful neutron fluxes at accelerator facilities suitable for universities and industrial laboratories. In addition to basic research these alternative neutron sources will be important for educational and training purposes. In a wider perspective this technology should make it possible to introduce neutron research and applications to industrial and national research centres in IAEA Member States that are unable to afford a high energy spallation neutron source and have no access to a research reactor

  9. Conceptual study of a compact accelerator-driven neutron source for radioisotope production, boron neutron capture therapy and fast neutron therapy

    Angelone, M; Rollet, S

    2002-01-01

    The feasibility of a compact accelerator-driven device for the generation of neutron spectra suitable for isotope production by neutron capture, boron neutron capture therapy and fast neutron therapy, is analyzed by Monte Carlo simulations. The device is essentially an extension of the activator proposed by Rubbia left bracket CERN/LHC/97-04(EET) right bracket , in which fast neutrons are diffused and moderated within a properly sized lead block. It is shown that by suitable design of the lead block, as well as of additional elements of moderating and shielding materials, one can generate and exploit neutron fluxes with the spectral features required for the above applications. The linear dimensions of the diffusing-moderating device can be limited to about 1 m. A full-scale device for all the above applications would require a fast neutron source of about 10**1**4 s**-**1, which could be produced by a 1 mA, 30 MeV proton beam impinging on a Be target. The concept could be tested at the Frascati Neutron Gener...

  10. JSNS of the J-Parc Project and Other Accelerator Driven Small Neutron Sources in Japan

    The spallation neutron source KENS utilizes the beam from the 500 MeV-10 μA-20 Hz (5 kW) proton booster synchrotron, which is an injector to the 12 GeV main ring for nuclear and particle physics experiments. The main ring only uses about 9 pulses out of 72 pulses, and the KENS and the muon facilities utilize the rest of the beam, which was discarded if not used by the facilities. The KENS facility is a very good example of a medium-scale accelerator-driven neutron source (ADNS). Because it is a relatively small-power source, we could fully optimize the target-moderator-reflector assembly using an ambient-temperature moderator and a solid methane cold moderator. It is noteworthy that solid methane gives us higher neutron flux than a hydrogen moderator, which cannot be used at a high-power source because of radiation damage to methane. Currently, the KENS facility has an instrument suite of 16 instruments. High-resolution powder diffractometer, Sirius, is one of such instruments, which has a Q-resolution of about 0.1%. Performance of the Sirius is almost similar to that of the HRPD at ISIS, which has more than 30 times higher proton intensity. One other example is the small and wide-angle diffractometer SWAN. It has a wide-angle detector bank as well as small-and medium detector banks, and give us unique opportunities to measure the very wide Q-range of 0.007 (0.013) ≤ Q ≤ 20 A-1 without moving the detector banks

  11. Neutronic Studies in Support of Accelerator-Driven Systems: The MUSE Experiments in the MASURCA Facility

    The MUSE program (multiplication with an external source) is in progress at the MASURCA critical facility at the Cadarache Research Center of the Commissariat a l'Energie Atomique in France. The program is dedicated to the physics studies of accelerator-driven systems in support of transmutation studies of minor actinides and long-lived fission products. It began in 1995 with the coupling of a Cf source in MASURCA and was followed by a commercial (d,T) source. In 2001, a specially constructed (d,D)/(d,T) neutron generator (GENEPI) was placed in MASURCA and the MUSE-4 program commenced.We describe the first phases of the MUSE-4 program, with data presented that were obtained up to about the summer of 2002. We present some results from the 'reference' configuration, which can operate at critical. We present traverses of measured fission reaction rates, with comparison to calculations. Also in the reference configuration, we performed activation foil measurements and present these results compared to calculations.Because a major objective of the MUSE program is to test and qualify methods of subcritical reactivity measurement, we have devoted a major portion of our studies to this area. We have used classical methods (rod drop, source multiplication) to attempt to measure the subcritical level. In these early phases we studied core configurations of around keff = 0.995. Deeper subcriticality (keff = 0.96) was achieved by inserting a safety rod.In addition to the methods mentioned above, we have devoted a lot of effort to pulse neutron source, fluctuation (Rossi-α and Feynman-α), and transfer function methods (e.g., cross-power spectral density). We present our preliminary results of all the methods, with some discussion regarding cross comparison

  12. Neutron fluctuations in accelerator driven and power reactors via backward master equations

    The transport of neutrons in a reactor is a random process, and thus the number of neutrons in a reactor is a random variable. Fluctuations in the number of neutrons in a reactor can be divided into two categories, namely zero noise and power reactor noise. As the name indicates, they dominate (i.e. are observable) at different power levels. The reasons for their occurrences and utilization are also different. In addition, they are described via different mathematical tools, namely master equations and the Langevin equation, respectively. Zero noise carries information about some nuclear properties such as reactor reactivity. Hence methods such as Feynman- and Rossi-alpha methods have been established to determine the subcritical reactivity of a subcritical system. Such methods received a renewed interest recently with the advent of the so-called accelerator driven systems (ADS). Such systems, intended to be used either for energy production or transuranium transmutation, will use a subcritical core with a strong spallation source. A spallation source has statistical properties that are different from those of the traditionally used radioactive sources which were also assumed in the derivation of the Feynman- and Rossi-alpha formulae. Therefore it is necessary to re-derive the Feynman- and Rossi-alpha formulae. Such formulae for ADS have been derived recently but in simpler neutronic models. One subject of this thesis is the extension of such formulae to a more general case in which six groups of delayed neutron precursors are taken into account, and the full joint statistics of the prompt and all delayed groups is included. The involved complexity problems are solved with a combination of effective analytical techniques and symbolic algebra codes. Power reactor noise carries information about parametric perturbation of the system. Langevin technique has been used to extract such information. In such a treatment, zero noise has been neglected. This is a pragmatic

  13. Sensitivity analysis of core neutronic parameters in accelerator driven subcritical reactors

    Highlights: • Sensitivity analysis of ADSR core neutronic parameters has been investigated. • Uniform and parabolic proton beam spatial distributions have been considered. • TRIGA reactor was considered as the case study of the problem. - Abstract: In this paper, sensitivity of the ADSRs core neutronic parameters to the accelerator related parameters such as beam profile, source multiplication coefficient (ks) and proton beam energy (Ep) has been investigated. TRIGA reactor has been considered as the case study of the problem. Monte Carlo code MCNPX has been used to calculate neutronic parameters such as: effective multiplication coefficient (keff), net neutron multiplication (M), spallation neutron yield (Yn/p), energy constant gain (G0), energy gain (G), importance of neutron source (φ*), axial and radial distributions of neutron flux and power peaking factor (Pmax/Pave) in two axial and radial directions of the reactor core for three eigen values levels (ks) including: 0.91, 0.97 and 0.99. According to the results, using a parabolic spatial distribution instead of a uniform spatial distribution increases the relative differences of spallation neutron yield, net neutron multiplication and energy gain by 4.74%, 4.05% and 10.26% respectively. In consequence the required accelerator current (Ip) will be reduced by 7.14% to preserve the reactivity. Although safety margin is decreased in highest case of ks, but energy gain increases by 93.43% and the required accelerator current and importance of neutrons source decrease by 48.3% and 2.64% respectively. In addition, increasing Ep from 115 MeV up to1 GeV, improves spallation neutron yield and energy gain by 2798.71% and 205.12% and decreases the required accelerator current and power by 96.83% and 72.44%, respectively. Therefore, our results are indicative of the fact that investigating sensitivity of the core neutronic parameters to the accelerator related parameters are necessary in order to optimally design a

  14. Conceptual design of thorium-fuelled Mitrailleuse accelerator-driven subcritical reactor using D-Be neutron source

    A distributed accelerator is a charged-particle accelerator that uses a new acceleration method based on repeated electrostatic acceleration. This method offers outstanding benefits not possible with the conventional radio-frequency acceleration method, including: (1) high acceleration efficiency, (2) large acceleration current, and (3) lower failure rate made possible by a fully solid-state acceleration field generation circuit. A 'Mitrailleuse Accelerator' is a product we have conceived to optimize this distributed accelerator technology for use with a high-strength neutron source. We have completed the conceptual design of a Mitrailleuse Accelerator and of a thorium-fuelled subcritical reactor driven by a Mitrailleuse Accelerator. This paper presents the conceptual design details and approach to implementing the subcritical reactor core. We will spend the next year or so on detailed design work, and then will start work on developing a prototype for demonstration. If there are no obstacles in setting up a development organization, we expect to finish verifying the prototype's performance by the third quarter of 2015. (authors)

  15. Monte Carlo studies of accelerator driven systems energy and spatial distribution of neutrons in multiplying and non-multiplying media

    Hashemi-Nezhad, S R; Brandt, R; Krivopustov, M I; Kulakov, B A; Odoj, R; Sosnin, A N; Wan, J S; Westmeier, W

    2002-01-01

    The LAHET code system is used to study the behaviour of the spallation neutrons resulting from the interaction of 2.5 GeV/c protons with a massive lead target within a large (approx 32 m sup 3) lead and graphite moderating environments. The spatial and energy distribution of the neutrons with presence and absence of a fissile material in Accelerator Driven Systems (ADS) are investigated. It is shown that the energy spectra of the neutrons in graphite and lead moderators are very different and such difference is expected to result in noticeable differences in the nuclear waste transmutation abilities of the ADSs that use graphite and lead for neutron moderation and storage.

  16. Monte Carlo studies of accelerator driven systems: energy and spatial distribution of neutrons in multiplying and non-multiplying media

    The LAHET code system is used to study the behaviour of the spallation neutrons resulting from the interaction of 2.5 GeV/c protons with a massive lead target within a large (∼32 m3) lead and graphite moderating environments. The spatial and energy distribution of the neutrons with presence and absence of a fissile material in Accelerator Driven Systems (ADS) are investigated. It is shown that the energy spectra of the neutrons in graphite and lead moderators are very different and such difference is expected to result in noticeable differences in the nuclear waste transmutation abilities of the ADSs that use graphite and lead for neutron moderation and storage

  17. Reactivity determination in accelerator driven nuclear reactors by statistics from neutron detectors (Feynman-Alpha Method)

    The Feynman-alpha method is used in traditional nuclear reactors to determine the subcritical reactivity of a system. The method is based on the measurement of the mean number and the variance of detector counts for different measurement times. The measurement is performed while a steady-state neutron flux is maintained in the reactor by an external neutron source, as a rule a radioactive source. From a plot of the variance-to-mean ratio as a function of measurement time ('gate length'), the reactivity can be determined by fitting the measured curve to the analytical solution. A new situation arises in the planned accelerator driven systems (ADS). An ADS will be run in a subcritical mode, and the steady flux will be maintained by an accelerator based source. Such a source has statistical properties that are different from those of a steady radioactive source. As one example, in a currently running European Community project for ADS research, the MUSE project, the source will be a periodically pulsed neutron generator. The theory of Feynman-alpha method needs to be extended to such nonstationary sources. There are two ways of performing and evaluating such pulsed source experiments. One is to synchronise the detector time gate start with the beginning of an incoming pulse. The Feynman-alpha method has been elaborated for such a case recently. The other method can be called stochastic pulsing. It means that there is no synchronisation between the detector time gate start and the source pulsing, i.e. the start of each measurement is chosen at a random time. The analytical solution to the Feynman-alpha formula from this latter method is the subject of this report. We have obtained an analytical Feynman-alpha formula for the case of stochastic pulsing by two different methods. One is completely based on the use of the symbolic algebra code Mathematica, whereas the other is based on complex function techniques. Closed form solutions could be obtained by both methods

  18. FAFNIR: Strategy and risk reduction in accelerator driven neutron sources for fusion materials irradiation data

    Surrey, E; Caballero, A; Davenne, T; Findlay, D; Letchford, A; Thomason, J; Marrow, J; Roberts, S; Seryi, A; Connolly, B; Mummery, P; Owen, H

    2014-01-01

    The need to populate the fusion materials engineering data base has long been recognized, the IFMIF facility being the present proposed neutron source for this purpose. Re-evaluation of the regulatory approach for the EU proposed DEMO device shows that the specification of the neutron source can be reduced with respect to IFMIF, allowing lower risk technology solutions to be considered. The justification for this approach is presented and a description of a proposed facility, FAFNIR, is presented with more detailed discussion of the accelerator and target designs.

  19. Monitoring method for neutron flux for a spallation target in an accelerator driven sub-critical system

    Zhao, Qiang, He, Zhi-Yong; Yang, Lei; Zhang, Xue-Ying; Cui, Wen-Juan; Chen, Zhi-Qiang; Xu, Hu-Shan

    2016-07-01

    In this paper, we study a monitoring method for neutron flux for the spallation target used in an accelerator driven sub-critical (ADS) system, where a spallation target located vertically at the centre of a sub-critical core is bombarded vertically by high-energy protons from an accelerator. First, by considering the characteristics in the spatial variation of neutron flux from the spallation target, we propose a multi-point measurement technique, i.e. the spallation neutron flux should be measured at multiple vertical locations. To explain why the flux should be measured at multiple locations, we have studied neutron production from a tungsten target bombarded by a 250 MeV-proton beam with Geant4-based Monte Carlo simulations. The simulation results indicate that the neutron flux at the central location is up to three orders of magnitude higher than the flux at lower locations. Secondly, we have developed an effective technique in order to measure the spallation neutron flux with a fission chamber (FC), by establishing the relation between the fission rate measured by FC and the spallation neutron flux. Since this relation is linear for a FC, a constant calibration factor is used to derive the neutron flux from the measured fission rate. This calibration factor can be extracted from the energy spectra of spallation neutrons. Finally, we have evaluated the proposed calibration method for a FC in the environment of an ADS system. The results indicate that the proposed method functions very well. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03010000 and XDA03030000) and the National Natural Science Foundation of China(91426301).

  20. Laser-driven x-ray and neutron source development for industrial applications of plasma accelerators

    Brenner, C.M.; Mirfayzi, S. R.; Rusby, D. R.; Armstrong, C; Alejo, A.; Wilson, L A; Clarke, R; Ahmed, H.; Butler, N. M H; Haddock, D; Higginson, A; McClymont, A.; Murphy, C; Notley, M.; Oliver, P

    2015-01-01

    Pulsed beams of energetic x-rays and neutrons from intense laser interactions with solid foils are promising for applications where bright, small emission area sources, capable of multi-modal delivery are ideal. Possible end users of laser-driven multi-modal sources are those requiring advanced non-destructive inspection techniques in industry sectors of high value commerce such as aerospace, nuclear and advanced manufacturing. We report on experimental work that demonstrates multi-modal oper...

  1. Nuclear energy generation and waste transmutation using an accelerator-driven intense thermal neutron source

    We describe a new approach for commercial nuclear energy production without a long-term high-level waste stream and for transmutation of both fission product and higher actinide commercial nuclear waste using a thermal flux of accelerator-produced neutrons in the 1016 n/cm2-s range. Continuous neutron fluxes at this intensity, which is approximately 100 times larger than is typically available in a large scale thermal reactor, appear practical owing to recent advances in proton linear accelerator technology and to the spallation target-moderator design presented here. This large flux of thermal neutrons makes possible a waste inventory in the transmutation system which is smaller by about a factor of 100 than competing concepts. The accelerator allows the system to operate well below criticality so that the possibility for a criticality accident is estimated. No control rods are required. The successful implementation of this new method for energy generation and waste transmutation would eliminate the need for nuclear waste storage on a geologic time scale. The production of nuclear energy from 232Th or 238U is used to illustrate the general principles of commercial nuclear energy production without long-term high-level waste. There is sufficient thorium to meet the world's energy needs for many millenia. 27 refs., 13 figs., 12 tabs

  2. Neutron cross-sections above 20 MeV for design and modeling of accelerator driven systems

    J Blomgren

    2007-02-01

    One of the outstanding new developments in the field of partitioning and transmutation (P&T) concerns accelerator-driven systems (ADS) which consist of a combination of a high-power, high-energy accelerator, a spallation target for neutron production and a sub-critical reactor core. The development of the commercial critical reactors of today motivated a large effort on nuclear data up to about 20 MeV, and presently several million data points can be found in various data libraries. At higher energies, data are scarce or even non-existent. With the development of nuclear techniques based on neutrons at higher energies, nowadays there is a need also for higher-energy nuclear data. To provide alternative to this lack of data, a wide program on neutron-induced data related to ADS for P&T is running at the 20–180 MeV neutron beam facility at `The Svedberg Laboratory' (TSL), Uppsala. The programme encompasses studies of elastic scattering, inelastic neutron production, i.e., (, ′) reactions, light-ion production, fission and production of heavy residues. Recent results are presented and future program of development is outlined.

  3. Neutronic studies in support of accelerator-driven systems: The MUSE experiments in the MASURCA facility

    Soule, R.; Assal, W.; Chaussonnet, P.; Destouches, C.; Domergue, C.; Jammes, C.; Laurens, J.-M.; Lebrat, J.-F.; Mellier, F.; Perret, G.; Rimpault, G.; Servière, H.; Imel, G.; M. Thomas, G.; VILLAMARIN D.

    2004-01-01

    The MUSE program (multiplication with an external source) is in progress at the MASURCA critical facility at the Cadarache Research Center of the Commissariat à l'Energie Atomique in France. The program is dedicated to the physics studies of accelerator-driven systems in support of transmutation studies of minor actinides and long-lived fission products. It began in 1995 with the coupling of a Cf source in MASURCA and was followed by a commercial (d,T) source. In 2001, a specially constructed...

  4. Neutronic Description of Accelerator Driven Systems: Coupling if MC High Energy Particles Interaction and Sn Low Energy Neutron Codes as Applied to Myrrha

    The Myrrha project (1) at SCK-CEN, the Belgian nuclear research centre, intends to design and develop a prototype accelerator driven system. Such a system will enable, next to other application fields (Technological demonstration, integral experiments validation,...), the benchmarking of the codes applied to assess the performances of the ADS. In the present situation we coupled, at SCK.CEN, the high energy Monte Carlo code HETC to the DORT/TORT S-N Neutron transport codes to perform the neutronic calculations of the Myrrha project. The HETC code is used to compute the space and energy distribution of the primary spallation neutron source, also including all other particles involved. The high energy cascade is calculated down to 20 MeV neutrons. Whereas the neutrons below this energy limit are stored as primary particles (without any interaction in the spallation medium) in a multigroup energy structure and will be treated as a fixed neutron source in the S-N transport code. The neutron interaction cross-section library used in this step is based on the ENDF/B-IV nuclear data. It is a 27 energy group with 7 groups below the thermal cut-off and allowing the up-scattering and the anisotropic scattering up to P3. The neutron transport calculations of the sub-critical assembly are performed using the DORT code either in Keff or fixed source with multiplication modes. Quadrature sets of S8 and S16 were used during these calculations. This calculational scheme was validated on basis of Monte Carlo calculational results and experimental data. In this paper we present the global calculational scheme as we applied it to Myrrh a and the corresponding results. (Author) 14 refs

  5. Experimental study on neutronics in bombardment of thick targets by high energy proton beams for accelerator-driven sub-critical system

    The experimental study on neutronics in the target region of accelerator-driven sub-critical system is carried out by using the high energy accelerator in Joint Institute for Nuclear Research, Dubna, Russia. The experiments with targets U(Pb), Pb and Hg bombarded by 0.533, 1.0, 3.7 and 7.4 GeV proton beams show that the neutron yield ratio of U(Pb) to Hg and Pb to Hg targets is (2.10 +- 0.10) and (1.76 +- 0.33), respectively. Hg target is disadvantageous to U(Pb) and Pb targets to get more neutrons. Neutron yield drops along 20 cm thick targets as the thickness penetrated by protons increases. The lower the energy of protons, the steeper the neutron yield drops. In order to get more uniform field of neutrons in the targets, the energy of protons from accelerators should not be lower than 1 GeV. The spectra of secondary neutrons produced by different energies of protons are similar, but the proportion of neutrons with higher energy gradually increases as the proton energy increases

  6. Study of deuteron-induced reactions for engineering design of accelerator-driven neutron sources

    A comprehensive research project is outlined on deuteron nuclear data consisting of measurement, theoretical model analysis, cross section evaluation, and application to radioisotope production for medical use. The goal is to develop a state-of-the-art deuteron nuclear data library up to 200 MeV which will be necessary for engineering design of future (d,xn) neutron sources. The current status and future plan are described. (author)

  7. A neutron booster for spallation sources--application to accelerator driven systems and isotope production

    Galy, J; Van Dam, H; Valko, J

    2002-01-01

    One can design a critical system with fissile material in the form of a thin layer on the inner surface of a cylindrical neutron moderator such as graphite or beryllium. Recently, we have investigated the properties of critical and near critical systems based on the use of thin actinide layers of uranium, plutonium and americium. The thickness of the required fissile layer depends on the type of fissile material, its concentration in the layer and on the geometrical arrangement, but is typically in the mu m-mm range. The resulting total mass of fissile material can be as low as 100 g. Thin fissile layers have a variety of applications in nuclear technology--for example in the design neutron amplifiers for medical applications and 'fast' islands in thermal reactors for waste incineration. In the present paper, we investigate the properties of a neutron booster unit for spallation sources and isotope production. In those applications a layer of fissile material surrounds the spallation source. Such a module cou...

  8. Accelerator driven radiation clean nuclear power system conceptual research symposium

    The R and D of ADS (Accelerators Driven Subcritical System) in China introduced. 31 theses are presented. It includes the basic principle of ADS, accelerators, sub-critical reactors, neutron physics, nuclear data, partitioning and transmutation

  9. Macroscopic cross sections of neutron radiation capture by Pb-208, U-238 and Tc-99 nuclides in the accelerator driven subcritical core cooled with molten Pb-208 - 286

    In the paper macroscopic cross sections for several isotopes: 208Pb, 238U, 99Tc and natural mix of lead isotopes, natPb, averaged over neutron spectra of the accelerator driven subcritical core cooled with natPb or 208Pb are given. It is shown that macro cross sections for a coolant from 208Pb are by 6.2 times smaller than those for the coolant consisted from natPb. The economy of neutrons in the core cooled with molten 208Pb can be used for reducing initial fuel load, increasing plutonium breeding and enhancing transmutation of such long lived fission products as 99Tc. The values of macro cross sections calculated for 238U and 99Tc, equal to 0.6 and 0.8 barns, respectively, are comparable with the values of the same nuclide macro cross sections for neutron spectrum of the fast reactor core cooled with sodium. Good neutron and physical features of molten 208Pb permit to assume it as perspective coolant for fast reactors and accelerator driven systems. (authors)

  10. Basic concept for an accelerator-driven subcritical system to be used as a long-pulse neutron source for Condensed Matter research

    A model for an accelerator-driven subcritical system to be operated as a source of cold neutrons for Condensed Matter research is developed at the conceptual level. Its baseline layout relies upon proven accelerator, spalattion target and fuel array technologies, and consists in a proton accelerator able to deliver some 67.5 mA of proton beam with kinetic energy 0.6 GeV, a pulse length of 2.86 ms, and repetition rate of 14 Hz. The particle beam hits a target of conventional design that is surrounded by a multiplicative core made of fissile/fertile material, composed by a subcritical array of fuel bars made of aluminium Cermet cooled by light water poisoned with boric acid. Relatively low enriched uranium is chosen as fissile material. An optimisation of several parameters is carried out, using as components of the objective function several characteristics pertaining the cold neutron pulse. The results show that the optimal device will deliver up to 80% of the cold neutron flux expected for some of the ongoing projects using a significantly lower proton beam power than that managed in such projects. The total power developed within the core rises up to 22.8 MW, and the criticality range shifts to a final keff value of around 0.9 after the 50 days cycle

  11. Basic concept for an accelerator-driven subcritical system to be used as a long-pulse neutron source for Condensed Matter research

    Vivanco, R., E-mail: raul.vivanco.sanchez@gmail.com [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Ghiglino, A.; Vicente, J.P. de; Sordo, F.; Terrón, S.; Magán, M. [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Perlado, J.M. [Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Bermejo, F.J. [Instituto de Estructura de la Materia, IEM-CSIC, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid (Spain)

    2014-12-11

    A model for an accelerator-driven subcritical system to be operated as a source of cold neutrons for Condensed Matter research is developed at the conceptual level. Its baseline layout relies upon proven accelerator, spalattion target and fuel array technologies, and consists in a proton accelerator able to deliver some 67.5 mA of proton beam with kinetic energy 0.6 GeV, a pulse length of 2.86 ms, and repetition rate of 14 Hz. The particle beam hits a target of conventional design that is surrounded by a multiplicative core made of fissile/fertile material, composed by a subcritical array of fuel bars made of aluminium Cermet cooled by light water poisoned with boric acid. Relatively low enriched uranium is chosen as fissile material. An optimisation of several parameters is carried out, using as components of the objective function several characteristics pertaining the cold neutron pulse. The results show that the optimal device will deliver up to 80% of the cold neutron flux expected for some of the ongoing projects using a significantly lower proton beam power than that managed in such projects. The total power developed within the core rises up to 22.8 MW, and the criticality range shifts to a final k{sub eff} value of around 0.9 after the 50 days cycle.

  12. Proliferation Potential of Accelerator-Driven Systems: Feasibility Calculations

    Accelerator-driven systems for fissile materials production have been proposed and studied since the early 1950s. Recent advances in beam power levels for small accelerators have raised the possibility that such use could be feasible for a potential proliferator. The objective of this study is to review the state of technology development for accelerator-driven spallation neutron sources and subcritical reactors. Energy and power requirements were calculated for a proton accelerator-driven neutron spallation source and subcritical reactors to produce a significant amount of fissile material--plutonium

  13. Accelerator driven assembly

    Balderas, J.; Cappiello, M.; Cummings, C.E.; Davidson, R. [and others

    1997-01-01

    This report addresses a Los Alamos National Laboratory (LANL) proposal to build a pulsed neutron source for simulating nuclear-weapons effects. A point design for the pulsed neutron facility was initiated early in FY94 after hosting a Defense Nuclear Agency (DNA) panel review and after subsequently visiting several potential clients and users. The technical and facility designs contained herein fulfill the Statement of Work (SOW) agreed upon by LANL and DNA. However, our point designs and parametric studies identify a unique, cost-effective, above-ground capability for neutron nuclear-weapons-effects studies at threat levels. This capability builds on existing capital installations and infrastructure at LANL. We believe that it is appropriate for us, together with the DNA, to return to the user community and ask for their comments and critiques. We also realize that the requirements of last year have changed significantly. Therefore, the present report is a `working document` that may be revised where feasible as we learn more about the most recent Department of Defense (DoD) and Department of Energy (DOE) needs.

  14. Accelerators for Driving Intense spallation Neutron Sources

    A worldwide trend to replace aging research reactors with accelerator driven neutron sources is currently underway. The ''SARAF'' program at Soreq NRC is a notable example. Setting the background to this trend, a review of the history of accelerator based spallation neutron sources is presented. We follow the evolution of ideas and projects for intense spallation neutron sources. The survey is mainly focused on the properties of the accelerators chosen as drivers throughout the evolution of spallation neutron sources. Since the late 1940s, high-energy proton and deuteron accelerators were developed in view of producing intense neutron sources for various applications related to the nuclear industry, i.e. breeding fissile isotopes, driving nuclear reactors using alternative fuels (like the 'Energy Amplifier') and nuclear waste incineration. However, these projects never progressed beyond the R and D stage. In recent years there is a trend to replace aging reactor-based strong cw neutron sources by pulsed intense spallation sources. Their main applications are in the fields of physics research, material sciences, biology and medicine. Prominent examples of successful projects are ISIS at RAL in Great Britain and SINQ at PSI in Switzerland. Other successful projects are noted in Japan and the US. The clear success of these spallation sources prompted the development of a new generation of more intense spallation neutron sources, notably in Europe (ESS), US (SNS) and Japan (JAERI). Generally, the pulsed spallation neutron sources are based on high-energy proton accelerators. Initially, the proton accelerators were room temperature linacs. In view of the progress relating to properties of RF superconducting resonators and the excellent accumulated experience with cryogenic accelerators, future accelerators for spallation sources will be mostly cryogenic linacs

  15. Laser driven particle acceleration

    This dissertation summarizes the last ten years of research at the Laboratory of Applied Optics on laser-plasma based electron acceleration. The main result consists of the development and study of a relativistic electron source with unique properties: high energy (100-300 MeV) in short distances (few millimeters), mono-energetic, ultra-short (few fs), stable and tunable. The manuscript describes the steps that led to understanding the physics, and then mastering it in order to produce this new electron source. Non linear propagation of the laser pulse in the plasma is first presented, with phenomena such as non linear wakefield excitation, relativistic and ponderomotive self-focusing in the short pulse regime, self-compression. Acceleration and injection of electrons are then reviewed from a theoretical perspective. Experimental demonstrations of self-injection in the bubble regime and then colliding pulse injection are then presented. These experiments were among the first to produce monoenergetic, high quality, stable and tunable electron beams from a laser-plasma accelerator. The last two chapters are dedicated to the characterization of the electron beam using transition radiation and to its applications to gamma radiography and radiotherapy. Finally, the perspectives of this research are presented in the conclusion. Scaling laws are used to determine the parameters that the electron beams will reach using peta-watt laser systems currently under construction. (author)

  16. Fission fragment driven neutron source

    Miller, Lowell G.; Young, Robert C.; Brugger, Robert M.

    1976-01-01

    Fissionable uranium formed into a foil is bombarded with thermal neutrons in the presence of deuterium-tritium gas. The resulting fission fragments impart energy to accelerate deuterium and tritium particles which in turn provide approximately 14 MeV neutrons by the reactions t(d,n).sup.4 He and d(t,n).sup.4 He.

  17. JAERI accelerator driven system project

    In Japan a national program called OMEGA was started in 1988 for research and development of new technologies for partitioning and transmutation of nuclear waste. Under this program JAERI is carrying out research and development for proton accelerator-driven transmutation, together with transmutation with fast burner reactor and advanced partitioning technology. Two types of accelerator driven transmutation systems are proposed: a solid system and a molten-salt system. An outline of the OMEGA program and the partitioning and transmutation studies at JAERI are presented in this report

  18. An overview of accelerator-driven transmutation technology

    Accelerator-Driven Transmutation Technology, or ADT2, is a collection of programs that share a common theme - they each have at their heart an intense source of neutrons generated by a high-energy proton beam striking a heavy metal target. The beam energy, typically 1000 MeV, is enough for a single proton to smash a target atom into atomic fragments. This so-called spallation process generates large numbers of neutrons (around 20 to 30 per proton) amid the atomic debris. These neutrons are of high value because they can be used to transmute neighboring atoms by neutron capture. Three distinct ADT2 program elements will be described. These are ADEP - accelerator-driven energy production, ABC - accelerator based conversion (of plutonium) and ATW - accelerator transmutation of waste

  19. Subcritical reactivity monitoring in accelerator driven systems

    In this paper, an absolute measurements technique for the subcriticality determination is presented. The development of accelerator driven systems (ADS) requires the development of methods to monitor and control the subcriticality of this kind of system, without interfering with its normal operation mode. This method is based on the stochastic neutron and photon transport theory that can be implemented by presently available neutron transport codes. As a by-product of the methodology a monitoring measurement technique has been developed and verified using two coupled Monte Carlo programs. The first one, LAHET, simulates the spallation collisions and the high energy transport and the other, MCNPDSP, is used to estimate the counting statistics from neutron ray counter in fissile system, and the transport for neutrons with energies less than 20 Mev. Through the analysis of the counter detectors it is possible to determine the kinetics parameters and the keff value. We present two different ways to obtain these parameters using the accelerator or using a Cf-252 source. A good agreement between theory and simulations has been obtained with both sources

  20. Accelerator-induced transients in Accelerator Driven Subcritical Reactors

    Achieving higher particles energies and beam powers have long been the main focus of research in accelerator technology. Since Accelerator Driven Subcritical Reactors (ADSRs) have become the subject of increasing interest, accelerator reliability and modes of operation have become important matters that require further research and development in order to accommodate the engineering and economic needs of ADSRs. This paper focuses on neutronic and thermo-mechanical analyses of accelerator-induced transients in an ADSR. Such transients fall into three main categories: beam interruptions (trips), pulsed-beam operation, and beam overpower. The concept of a multiple-target ADSR is shown to increase system reliability and to mitigate the negative effects of beam interruptions, such as thermal cyclic fatigue in the fuel cladding and the huge financial cost of total power loss. This work also demonstrates the effectiveness of the temperature-to-reactivity feedback mechanisms in ADSRs. A comparison of shutdown mechanisms using control rods and beam cut-off highlights the intrinsic safety features of ADSRs. It is evident that the presence of control rods is crucial in an industrial-scale ADSR. This paper also proposes a method to monitor core reactivity online using the repetitive pattern of beam current fluctuations in a pulsed-beam operation mode. Results were produced using PTS-ADS, a computer code developed specifically to study the dynamic neutronic and thermal responses to beam transients in subcritical reactor systems.

  1. Neutrons from medical electron accelerators

    The significant sources of photoneutrons within a linear-accelerator treatment head are identified and absolute estimates of neutron production per treatment dose are given for typical components. Measured data obtained at a variety of accelerator installations are presented and compared with these calculations. It is found that the high-Z materials within the treatment head do not significantly alter the neutron fluence, but do substantially reduce the average energy of the transmitted spectrum. Reflected neutrons from the concrete treatment room contribute to the neutron fluence, but not substantially to the patient integral dose, because of a further reduction in average energy. Absolute depth-dose distributions for realistic neutron spectra are calculated, and a rapid falloff with depth is found

  2. A proposal on fundamental experimental device and R and D of nuclear astrophysics accelerator driven system using neutron beam line in the matter and life science; experimental facility

    Nuclear astrophysics and nuclear data section propose construction and establishment of 'nuclear a strophic accelerator drive system R and D fundamental experimental device' in 'the matter and life science experimental facility' of 'High-Intensity Proton Accelerator Project'. This report states background of proposal on the device, summary and characteristics of the device, research themes and program after completion of it. An accurate data of neutron induced reaction cross section, neutron capture cross section, neutron capture rate and fission cross section are necessary to solve the problems on nuclear a strophic and to treat and transform LLFP (long-lived fission product) and MA (minor actinides). (S.Y.)

  3. Neutron importance in source-driven systems

    A study of integral indicators of the neutron source importance in source-driven systems is carried out and their dependence on the phase-space characteristics of the neutron source is investigated in the first part of the paper. The second part is devoted to the analysis of the solution of the source-driven adjoint model, introducing different detectors as far as the spatial location and the energy is concerned. Spatial, angular and spectral effects are evidenced, solving the transport equation for a 2-dimensional x-y configuration in the multigroup SN approximation. Various definitions of the adjoint problem may be used in the interpretation of local flux measurements in source-driven subcritical systems and in the weighting procedures for the development of computational methods for transient analyses. The definition of the appropriate problem-dependent detector is still an open question and an object of discussion within the accelerator-driven system community. Some results showing the effects of different choices of the adjoint source on the effective mean neutron lifetime are illustrated. (authors)

  4. Accelerator-driven transmutation reactor analysis code system (ATRAS)

    Sasa, Toshinobu; Tsujimoto, Kazufumi; Takizuka, Takakazu; Takano, Hideki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    JAERI is proceeding a design study of the hybrid type minor actinide transmutation system which mainly consist of an intense proton accelerator and a fast subcritical core. Neutronics and burnup characteristics of the accelerator-driven system is important from a view point of the maintenance of subcriticality and energy balance during the system operation. To determine those characteristics accurately, it is necessary to involve reactions at high-energy region, which are not treated on ordinary reactor analysis codes. The authors developed a code system named ATRAS to analyze the neutronics and burnup characteristics of accelerator-driven subcritical reactor systems. ATRAS has a function of burnup analysis taking account of the effect of spallation neutron source. ATRAS consists of a spallation analysis code, a neutron transport codes and a burnup analysis code. Utility programs for fuel exchange, pre-processing and post-processing are also incorporated. (author)

  5. Accelerator-driven transmutation reactor analysis code system (ATRAS)

    JAERI is proceeding a design study of the hybrid type minor actinide transmutation system which mainly consist of an intense proton accelerator and a fast subcritical core. Neutronics and burnup characteristics of the accelerator-driven system is important from a view point of the maintenance of subcriticality and energy balance during the system operation. To determine those characteristics accurately, it is necessary to involve reactions at high-energy region, which are not treated on ordinary reactor analysis codes. The authors developed a code system named ATRAS to analyze the neutronics and burnup characteristics of accelerator-driven subcritical reactor systems. ATRAS has a function of burnup analysis taking account of the effect of spallation neutron source. ATRAS consists of a spallation analysis code, a neutron transport codes and a burnup analysis code. Utility programs for fuel exchange, pre-processing and post-processing are also incorporated. (author)

  6. Terahertz-driven linear electron acceleration

    Nanni, Emilio Alessandro; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Miller, R J Dwayne; Kärtner, Franz X

    2014-01-01

    The cost, size and availability of electron accelerators is dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency (RF) accelerating structures operate with 30-50 MeV/m gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional RF structures. However, laser-driven electron accelerators require intense sources and suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here, we demonstrate the first linear acceleration of electrons with keV energy gain using optically-generated terahertz (THz) pulses. THz-driven accelerating structures enable high-gradient electron accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. Increasing the operational frequency of accelerators into the THz band allows for greatly increased accelerating ...

  7. Linac-driven spallation-neutron source

    Strong interest has arisen in accelerator-driven spallation-neutron sources that surpass existing facilities (such as ISIS at Rutherford or LANSCE at Los Alamos) by more than an order of magnitude in beam power delivered to the spallation target. The approach chosen by Los Alamos (as well as the European Spallation Source) provides the full beam energy by acceleration in a linac as opposed to primary acceleration in a synchrotron or other circular device. Two modes of neutron production are visualized for the source. A short-pulse mode produces 1 MW of beam power (at 60 pps) in pulses, of length less than 1 ms, by compression of the linac macropulse through multi-turn injection in an accumulator ring. A long-pulse mode produces a similar beam power with 1-ms-long pulses directly applied to a target. This latter mode rivals the performance of existing reactor facilities to very low neutron energies. Combination with the short-pulse mode addresses virtually all applications

  8. High-current deuteron cyclotron complex as meson and neutron generator for accelerator driven transmutation technology (ADTT) and energy production

    The research and development results are given for the Deuteron Cyclotron Complex with the final energy about 900 MeV/nucleon and average beam intensity in the milli ampere range. The complex consists of a radiofrequency quadrupole linear accelerator (RFQ-linac) and two superconducting sector cyclotrons DC-I and DC-II. The possibility of replacing a linac by a cyclotron injector with the deuteron energy 15 MeV and with 'warm' or superconducting sector magnets is discussed. A DC-II version with 10 superconducting sector magnets and 6 main and 2 flat-top radio frequency (RF) resonators is proposed. Information on the constructing of the full-scale prototype for several DC-I systems is given

  9. Uncertainty assessment for accelerator-driven systems

    The concept of a subcritical system driven by an external source of neutrons provided by an accelerator ADS (Accelerator Driver System) has been recently revived and is becoming more popular in the world technical community with active programs in Europe, Russia, Japan, and the U.S. A general consensus has been reached in adopting for the subcritical component a fast spectrum liquid metal cooled configuration. Both a lead-bismuth eutectic, sodium and gas are being considered as a coolant; each has advantages and disadvantages. The major expected advantage is that subcriticality avoids reactivity induced transients. The potentially large subcriticality margin also should allow for the introduction of very significant quantities of waste products (minor Actinides and Fission Products) which negatively impact the safety characteristics of standard cores. In the U.S. these arguments are the basis for the development of the Accelerator Transmutation of Waste (ATW), which has significant potential in reducing nuclear waste levels. Up to now, neutronic calculations have not attached uncertainties on the values of the main nuclear integral parameters that characterize the system. Many of these parameters (e.g., degree of subcriticality) are crucial to demonstrate the validity and feasibility of this concept. In this paper we will consider uncertainties related to nuclear data only. The present knowledge of the cross sections of many isotopes that are not usually utilized in existing reactors (like Bi, Pb-207, Pb-208, and also Minor Actinides and Fission Products) suggests that uncertainties in the integral parameters will be significantly larger than for conventional reactor systems, and this raises concerns on the neutronic performance of those systems

  10. Accelerator-Driven System with Current Technology

    World needs a safer and cleaner nuclear power plant. A nuclear power plant that will not cause a disaster and that will produce radiotoxic nuclear waste as small as possible. At the moment, the closest system is the accelerator driven system (ADS) making use of the Thorium fuel. First of all, it is safer in a disaster such as an earthquake, because the deriving accelerator stops immediately by the earthquake. And, there won't be a Fukushima-like accident, because this Thorium ADS reactor uses air cooling. It also minimizes the nuclear waste problem by reducing the amount of the toxic waste and shortening their half lifetime to only a few hundred years. Finally, it solves the Uranium reserve problem. The Thorium reserve is much larger than that of Uranium. Although the idea of ADS was proposed long time ago, it has not been utilized yet first by technical difficulty of accelerator. The accelerator-based system needs 0.6-1 GeV and at least a few MW power proton beam, which is an unprecedentedly high power. The most powerful 1 GeV proton linear accelerator is the Spallation Neutron Source, USA, which operates now at the power of 1.5 MW with the length of 350 m. A conventional linear accelerator would need several hundred m length, which is highly costly particularly in Korea because of the high land cost. Another difficulty is reliability of accelerator operation. To be used as a power plant facility, accelerator should obviously operate such that the power plant may continuously generate electricity at least for months with no interruption. However, the reality is that a high power proton accelerator is hardly operated even a few hours without interruption, although very short interruptions are tolerable. Anyway, it will take a time to develop an accelerator sufficiently reliable to be used for power generation. Now the question is if it is possible to realize ADS with the current level of accelerator technology. This paper seeks the possibility

  11. Accelerator-Driven System with Current Technology

    Lee, Hee Seok; Lee, Tae Yeon [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)

    2013-10-15

    World needs a safer and cleaner nuclear power plant. A nuclear power plant that will not cause a disaster and that will produce radiotoxic nuclear waste as small as possible. At the moment, the closest system is the accelerator driven system (ADS) making use of the Thorium fuel. First of all, it is safer in a disaster such as an earthquake, because the deriving accelerator stops immediately by the earthquake. And, there won't be a Fukushima-like accident, because this Thorium ADS reactor uses air cooling. It also minimizes the nuclear waste problem by reducing the amount of the toxic waste and shortening their half lifetime to only a few hundred years. Finally, it solves the Uranium reserve problem. The Thorium reserve is much larger than that of Uranium. Although the idea of ADS was proposed long time ago, it has not been utilized yet first by technical difficulty of accelerator. The accelerator-based system needs 0.6-1 GeV and at least a few MW power proton beam, which is an unprecedentedly high power. The most powerful 1 GeV proton linear accelerator is the Spallation Neutron Source, USA, which operates now at the power of 1.5 MW with the length of 350 m. A conventional linear accelerator would need several hundred m length, which is highly costly particularly in Korea because of the high land cost. Another difficulty is reliability of accelerator operation. To be used as a power plant facility, accelerator should obviously operate such that the power plant may continuously generate electricity at least for months with no interruption. However, the reality is that a high power proton accelerator is hardly operated even a few hours without interruption, although very short interruptions are tolerable. Anyway, it will take a time to develop an accelerator sufficiently reliable to be used for power generation. Now the question is if it is possible to realize ADS with the current level of accelerator technology. This paper seeks the possibility.

  12. Developments in laser-driven plasma accelerators

    Hooker, Simon Martin

    2014-01-01

    Laser-driven plasma accelerators provide acceleration gradients three orders of magnitude greater than conventional machines, offering the potential to shrink the length of accelerators by the same factor. To date, laser-acceleration of electron beams to particle energies comparable to those offered by synchrotron light sources has been demonstrated with plasma acceleration stages only a few centimetres long. This article describes the principles of operation of laser-driven plasma accelerators, and reviews their development from their proposal in 1979 to recent demonstrations. The potential applications of plasma accelerators are described and the challenges which must be overcome before they can become a practical tool are discussed.

  13. Spectrum shaping of accelerator-based neutron beams for BNCT

    Montagnini, B; Esposito, J; Giusti, V; Mattioda, F; Varone, R

    2002-01-01

    We describe Monte Carlo simulations of three facilities for the production of epithermal neutrons for Boron Neutron Capture Therapy (BNCT) and examine general aspects and problems of designing the spectrum-shaping assemblies to be used with these neutron sources. The first facility is based on an accelerator-driven low-power subcritical reactor, operating as a neutron amplifier. The other two facilities have no amplifier and rely entirely on their primary sources, a D-T fusion reaction device and a conventional 2.5 MeV proton accelerator with a Li target, respectively.

  14. Accelerator system for neutron radiography

    The field of x-ray radiography is well established for doing non-destructive evaluation of a vast array of components, assemblies, and objects. While x-rays excel in many radiography applications, their effectiveness diminishes rapidly if the objects of interest are surrounded by thick, high-density materials that strongly attenuate photons. Due to the differences in interaction mechanisms, neutron radiography is highly effective in imaging details inside such objects. To obtain a high intensity neutron source suitable for neutron imaging a 9-MeV linear accelerator is being evaluated for putting a deuteron beam into a high-pressure deuterium gas cell. As a windowless aperture is needed to transport the beam into the gas cell, a low-emittance is needed to minimize losses along the high-energy beam transport (HEBT) and the end station. A description of the HEBT, the transport optics into the gas cell, and the requirements for the linac will be presented

  15. Alternative definitions of kinetic parameters for accelerator driven systems

    Highlights: ► New definition of kinetic parameters for accelerator driven systems. ► Difference between effective and average delayed neutron fraction. ► Difference between effective and average prompt neutron lifetime. ► Effect of the neutron source (Cf, D–D, D–T) on ksrc. ► Effect of the (n, xn) reactions and source energy-angle distribution on ksrc. - Abstract: This study introduces a new formulation of kinetic parameters for accelerator driven systems and it is structured into two parts. The first part is dedicated to the classic definition of the kinetic parameters and compares different calculation methodologies. The second part considers a new definition of the kinetic parameters for subcritical assemblies, with particular emphasis on the delayed neutron fraction and the prompt neutron lifetime. This new definition takes into account neutrons from the external neutron source and (n, xn) reactions, which increase the fraction of prompt neutrons. The developed theoretical framework has been applied by Monte Carlo and deterministic calculations to the YALINA Thermal subcritical assembly located in Belarus. This facility can be driven by californium, deuterium–deuterium (D–D), or deuterium–tritium (D–T) external neutron sources. For the D–T neutron source, (n, xn) reactions must be taken into account in order to produce accurate results because the average energy of D–T source neutrons is 14.1 MeV, a value which is much higher than the threshold energy of the (n, 2n) cross section of uranium isotopes.

  16. Proton-driven plasma acceleration at CERN

    Plasma-based acceleration methods have seen important progress over the last years. Recently, it has been proposed to experimentally study plasma acceleration driven by proton beams, in addition to the established research directions of electron and laser-driven plasmas. This talk presents the planned experiment and the research efforts carried out at CERN.

  17. Terahertz-driven linear electron acceleration

    Nanni, Emilio A.; Huang, Wenqian R.; Hong, Kyung-Han; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Dwayne Miller, R. J.; Kärtner, Franz X.

    2015-10-01

    The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30-50 MeV m-1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/proton accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. These ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams.

  18. Accelerator-driven transmutation technologies

    The basic principles of accelerator-driven transmutation technologies (ADTT) are outlined and their assets highlighted. Current designs of ADTT facilities pursue 3 basic objectives: (i) Systems designed to generate power and convert nuclear wastes produced by conventional nuclear reactors into long-lived radioisotopes by transmutation. Such isotopes will be separated from molten salts by centrifugal separation. A single subcritical assembly will 'burn' wastes produced by several conventional NPPs. (ii) Systems for power generation using thorium fuel. Such systems are not designed for transmutation of nuclear wastes. The amount of transuranium elements produced by the thorium cycle is minimal, whereby the problem of storage of very long lived isotopes is virtually eliminated. (iii) Systems for transmutation of plutonium reclaimed from nuclear weapons. As to the future of ADTT in comparison with nuclear fusion, an asset of the former is that there remain no unsolved principal physical problems that would preclude its implementation. What has to be solved is materials and technological problems and, in particular, the financial problem. Implementation of ADTT is impossible in any way other than on the basis of a wide international cooperation. There exists a group of people dealing with ADTT in the Czech Republic, joining academic and industrial experts; this group is fostering contacts with the Los Alamos National Laboratory, U.S.A. The Institute of Nuclear Physics, Academy of Sciences of the Czech Republic, has set up an ADTT Documentation Center, which is accessible to any person interested in this promising field of science and technology. (P.A.). 3 figs

  19. Laser-driven electron accelerators

    The following possibilities are discussed: inverse free electron laser (wiggler accelerator); inverse Cerenkov effect; plasma accelerator; dielectric tube; and grating linac. Of these, the grating acceleraton is considered the most attractive alternative

  20. Small type accelerator. Try for accelerator driven system

    Mori, Y

    2003-01-01

    FFAG (Fixed-field alternating gradient) accelerator for accelerator driven subcritical reactor, which aims to change from long-lived radioactive waste to short-lived radioactivity, is introduced. It is ring accelerator. The performance needed is proton as accelerator particle, 10MW (total) beam power, about 1GeV beam energy, >30% power efficiency and continuous beam. The feature of FFAG accelerator is constant magnetic field. PoP (Proof-of-principle)-FFAG accelerator, radial type, was run at first in Japan in 2000. The excursion is about some ten cm. In principle, beam can be injected and extracted at any place of ring. The 'multi-fish' acceleration can accelerate beams to 100% duty by repeating acceleration. 150MeV-FFAG accelerator has been started since 2001. It tried to practical use, for example, treatment of cancer. (S.Y.)

  1. A bright neutron source driven by relativistic transparency of solids

    Roth, M.; Jung, D.; Falk, K.; Guler, N.; Deppert, O.; Devlin, M.; Favalli, A.; Fernandez, J.; Gautier, D. C.; Geissel, M.; Haight, R.; Hamilton, C. E.; Hegelich, B. M.; Johnson, R. P.; Kleinschmidt, A.; Merrill, F.; Schaumann, G.; Schoenberg, K.; Schollmeier, M.; Shimada, T.; Taddeucci, T.; Tybo, J. L.; Wagner, F.; Wender, S. A.; Wilde, C. H.; Wurden, G. A.

    2016-03-01

    Neutrons are a unique tool to alter and diagnose material properties and excite nuclear reactions with a large field of applications. It has been stated over the last years, that there is a growing need for intense, pulsed neutron sources, either fast or moderated neutrons for the scientific community. Accelerator based spallation sources provide unprecedented neutron fluxes, but could be complemented by novel sources with higher peak brightness that are more compact. Lasers offer the prospect of generating a very compact neutron source of high peak brightness that could be linked to other facilities more easily. We present experimental results on the first short pulse laser driven neutron source powerful enough for applications in radiography. For the first time an acceleration mechanism (BOA) based on the concept of relativistic transparency has been used to generate neutrons. This mechanism not only provides much higher particle energies, but also accelerated the entire target volume, thereby circumventing the need for complicated target treatment and no longer limited to protons as an intense ion source. As a consequence we have demonstrated a new record in laser-neutron production, not only in numbers, but also in energy and directionality based on an intense deuteron beam. The beam contained, for the first time, neutrons with energies in excess of 100 MeV and showed pronounced directionality, which makes then extremely useful for a variety of applications. The results also address a larger community as it paves the way to use short pulse lasers as a neutron source. They can open up neutron research to a broad academic community including material science, biology, medicine and high energy density physics as laser systems become more easily available to universities and therefore can complement large scale facilities like reactors or particle accelerators. We believe that this has the potential to increase the user community for neutron research largely.

  2. Use of accelerator based neutron sources

    With the objective of discussing new requirements related to the use of accelerator based neutron generators an Advisory Group meeting was held in October 1998 in Vienna. This meeting was devoted to the specific field of the utilization of accelerator based neutron generators. This TECDOC reports on the technical discussions and presentations that took place at this meeting and reflects the current status of neutron generators. The 14 MeV neutron generators manufactured originally for neutron activation analysis are utilised also for nuclear structure and reaction studies, nuclear data acquisition, radiation effects and damage studies, fusion related studies, neutron radiography

  3. Progress of Laser-Driven Plasma Accelerators

    There is a great interest worldwide in plasma accelerators driven by ultra-intense lasers which make it possible to generate ultra-high gradient acceleration and high quality particle beams in a much more compact size compared with conventional accelerators. A frontier research on laser and plasma accelerators is focused on high energy electron acceleration and ultra-short X-ray and Tera Hertz radiations as their applications. These achievements will provide not only a wide range of sciences with benefits of a table-top accelerator but also a basic science with a tool of ultrahigh energy accelerators probing an unknown extremely microscopic world.Harnessing the recent advance of ultra-intense ultra-short pulse lasers, the worldwide research has made a tremendous breakthrough in demonstrating high-energy high-quality particle beams in a compact scale, so called ''dream beams on a table top'', which represents monoenergetic electron beams from laser wakefield accelerators and GeV acceleration by capillary plasma-channel laser wakefield accelerators. This lecture reviews recent progress of results on laser-driven plasma based accelerator experiments to quest for particle acceleration physics in intense laser-plasma interactions and to present new outlook for the GeV-range high-energy laser plasma accelerators

  4. Characterization of short-pulse laser driven neutron source

    Falk, Katerina; Jung, Daniel; Guler, Nevzat; Deppert, Oliver; Devlin, Matthew; Fernandez, J. C.; Gautier, D. C.; Geissel, M.; Haight, R. C.; Hegelich, B. M.; Henzlova, Daniela; Ianakiev, K. D.; Iliev, Metodi; Johnson, R. P.; Merrill, F. E.; Schaumann, G.; Schoenberg, K.; Shimada, T.; Taddeucci, T. N.; Tybo, J. L.; Wagner, F.; Wender, S. A.; Wurden, G. A.; Favalli, Andrea; Roth, Markus

    2014-10-01

    We present a full spectral characterization of a novel laser driven neutron source, which employed the Break Out Afterburner ion acceleration mechanism. Neutrons were produced by nuclear reactions of the ions deposited on Be or Cu converters. We observed neutrons at energies up to 150 MeV. The neutron spectra were measured by five neutron time-of-flight detectors at various positions and distances from the source. The nTOF detectors observed that emission of neutrons is a superposition of an isotropic component peaking at 3.5--5 MeV resulting from nuclear reactions in the converter and a directional component at 25--70 MeV, which was a product of break-up reaction of the forward moving deuterons. Energy shifts due to geometrical effects in BOA were also observed.

  5. Candidate molten salt investigation for an accelerator driven subcritical core

    SOOBY Elizabeth; Baty, Austin; BENES ONDREJ; McIntyre, Peter; Pogue, Nathaniel; Salanne, Mathieu; Sattarov, Akhdiyor

    2013-01-01

    We report a design for accelerator-driven subcritical fission in a molten salt core (ADSMS) that utilizes a fuel salt composed of NaCl and transuranic (TRU) chlorides. The ADSMS core is designed for fast neutronics (28% of neutrons >1 MeV) to optimize TRU destruction. The choice of a NaCl-based salt offers benefits for corrosion, operating temperature, and actinide solubility as compared with LiF-based fuel salts. Molecular dynamics (MD) codes have been used to estimate properties of the molt...

  6. Technology of magnetically driven accelerators

    The marriage of Induction Linac technology with Nonlinear Magnetic Modulators has produced some unique capabilities. It appears possible to produce electron beams with average currents measured in amperes, at gradients exceeding 1 MeV/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator has been constructed at the Lawrence Livermore National Laboratory (LLNL) to demonstrate these concepts and to provide a test facility for high brightness sources. The pulse drive for the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak power capability, repetition rates exceeding a kilohertz and excellent reliability. 8 figs., 1 tab

  7. Diagnostics for laser-driven plasma accelerators

    When generating relativistic plasmas with high power laser systems small-scale particle accelerators can be realized producing particle pulses which exhibit parameters complementary to conventional accelerators. To be able to resolve the physical processes underlying the acceleration mechanisms diagnostics well-suited for this plasma environment need to be designed and realized. In this presentation, several techniques are introduced, and recent results are discussed. They have lead to the first time-resolved visualization of the plasma wave necessary for laser-driven electron acceleration, its non-linear evolution and the actual breaking of the plasma wave. Furthermore, diagnostic techniques relevant for laser-driven ion acceleration based on optical and particle probing are presented.

  8. Accelerator based neutron source for neutron capture therapy

    Full text: The Budker Institute of Nuclear Physics (Novosibirsk) and the Institute of Physics and Power Engineering (Obninsk) have proposed an accelerator based neutron source for neutron capture and fast neutron therapy for hospital. Innovative approach is based upon vacuum insulation tandem accelerator (VITA) and near threshold 7Li(p,n)7Be neutron generation. Pilot accelerator based neutron source for neutron capture therapy is under construction now at the Budker Institute of Nuclear Physics, Novosibirsk, Russia. In the present report, the pilot facility design is presented and discussed. Design features of facility components are discussed. Results of experiments and simulations are presented. Complete experimental tests are planned by the end of the year 2005

  9. TRIGA Accelerator Driven Experiment (TRADE)

    This short report is derivated from the TRADE FINAL FEASIBILITY REPORT (March 2002) that is the result of the collective effort of a Working Group composed by ENEA, CEA, CERN, ANSALDO under Carlo Rubbia (ENEA) and Massimo Salvatores (CEA) supervision. The TRADE experiment, to be performed in the TRIGA reactor of the ENEA Casaccia Centre consists in the coupling of an external proton accelerator to a target to be installed in the Central thimble of the reactor scrammed to sub-criticality. This pilot experiment, aimed at a global demonstration of the ADS concept, is based on an original idea of Carlo Rubbia, presented at CEA in October 2000. (author)

  10. Introduction to Physical and Technical Analysis of Accelerator Driven System

    In the present paper the main elements of the accelerator driven system (ADS) are discussed. Describing the spallation source it is underlined that beside the well accepted theory of spallation, the spallation phenomena is not yet sufficiently investigated. Dealing with the sub-critical reactor as an energy amplifier of the primary spallation source a suggestion for the specific neutron spectrum is proposed to obtain optimal conditions for energy production, burn-up and transmutation. In the chapter devoted for the accelerators which accelerates the charged particles, the two accelerator principles are presented on the examples of working accelerators: the linear accelerator - LINAC and cyclotron. Finally, there is presented the project of accelerator driven system - MYRHA for research and development worked out by the Belgian Nuclear Research Centre - SCK-CEN and the conception of nuclear power station of RBMK-1000 type with spallation source together with analysis of the balance of energy worked out by the Joint Institute of Nuclear Research, Dubna, Russia. (author)

  11. Weapon plutonium in accelerator driven power system

    Accelerator Driven Systems are planned to be developed for the use (or destruction) of dozens of tons of weapon-grade Plutonium (W-Pu) resulted from the reducing of nuclear weapons. In the paper are compared the parameters of various types of accelerators, the physical properties of various types of targets and blankets, and the results of fuel cycle simulation. Some economical aspects are also discussed

  12. Proton-driven plasma-wakefield acceleration

    Caldwell, Allen; Pukhov, Alexander; Simon, Frank

    2013-01-01

    Plasmas excited by laser beams or bunches of relativistic electrons have been used to produce electric fields of 10–100 GV m$^{-1}$. This has opened up the possibility of building compact particle accelerators at the gigaelectronvolt scale. However, it is not obvious how to scale these approaches to the energy frontier of particle physics—the teraelectronvolt regime. Here, we introduce the possibility of proton-bunch-driven plasma-wakefield acceleration, and demonstrate through numerical simulations that this energy regime could be reached in a single accelerating stage.

  13. Physics study of D-D/D-T neutron driven experimental subcritical assembly

    An experimental program to design and study external source driven subcritical assembly has been initiated at BARC. This program is aimed at understanding neutronic characteristics of accelerator driven system at low power level. In this series, a zero-power, sub-critical assembly driven by a D-D/D-T neutron generator has been developed. This system is modular in design and it is first in the series of subcritical assemblies being designed

  14. IAEA activities on accelerator-driven systems

    A brief account is given of the following IAEA programmes and events: Special Scientific Programme on 'Use of High Energy Accelerators for Transmutation of Actinides and Power Production'; Status report on actinide and fission product transmutation studies; Accelerator-driven systems: energy generation and transmutation of nuclear waste (status report); Coordinated Research Programme on the Use of Thorium-based Fuel Cycle in Accelerator Driven Systems to Incinerate Plutonium and to Reduce Long-term Waste Toxicities; Technical Committee Meeting on 'Feasibility and Motivation for Hybrid Concepts for Nuclear Energy Generation and Transmutation'; Data-base on experimental facilities and computer codes for ADS related research and development; Co-ordinated Research Project (CRP) on Safety, Environmental and Non-Proliferation Aspects of Partitioning and Transmutation of Actinides and Long-lived Fission Products. (P.A.)

  15. Accelerator requirements for fast-neutron interrogation of luggage and cargo

    Several different fast-neutron based techniques are being studied for the detection of contraband substances in luggage and cargo containers. The present work discusses the accelerator requirements for fast-neutron transmission spectroscopy (FNTS), pulsed fast-neutron analysis (PFNA), and 14-MeV neutron interrogation. These requirements are based on the results of Monte-Carlo simulations of neutron or gamma detection rates. Accelerator requirements are driven by count-rate considerations, spatial resolution and acceptable uncertainties in elemental compositions. The authors have limited their analyses to luggage inspection with FNTS and to cargo inspection with PFNA or 14-MeV neutron interrogation

  16. Neutron Production Using Alpha-Be Reaction on the Neutron Generator Accelerator

    In order to obtain data for development of small scale Accelerator Driven System (ADS), calculations of neutron production that use alpha-Be reaction on the acceleration energy range of 100 to 500 keV have been carried out. The result of neutron yield calculation was compared with calculation result of D-T reaction and both calculations were treated for thick target. At the energy of 100 keV; alpha-Be reaction produces neutron yield about 1/10 compared to that of D-T reaction and increases to 1/5 at energy of 500 keV. At the same acceleration voltage of 250 kV, where the alpha energy is 500 keV and deuteron energy is 250 keV; the neutron yield of alpha-Be reaction is 1/3 of that in D-T reaction. On the last mentioned condition and considering that target cost of Be is cheaper than the cost of T, neutron production on a neutron generator accelerator that uses alpha-Be reaction is a competitive method as neutron source, especially for ADS. (author)

  17. Cosmic acceleration driven by mirage inhomogeneities

    A cosmological model based on an inhomogeneous D3-brane moving in an AdS5 x S5 bulk is introduced. Although there are no special points in the bulk, the brane universe has a centre and is isotropic around it. The model has an accelerating expansion and its effective cosmological constant is inversely proportional to the distance from the centre, giving a possible geometrical origin for the smallness of a present-day cosmological constant. Besides, if our model is considered as an alternative of early-time acceleration, it is shown that the early stage accelerating phase ends in a dust-dominated FRW homogeneous universe. Mirage-driven acceleration thus provides a dark matter component for the brane universe final state. We finally show that the model fulfils the current constraints on inhomogeneities

  18. An Accelerator Neutron Source for BNCT

    The overall goal of this project was to develop an accelerator-based neutron source (ABNS) for Boron Neutron Capture Therapy (BNCT). Specifically, our goals were to design, and confirm by measurement, a target assembly and a moderator assembly that would fulfill the design requirements of the ABNS. These design requirements were (1) that the neutron field quality be as good as the neutron field quality for the reactor-based neutron sources for BNCT, (2) that the patient treatment time be reasonable, (3) that the proton current required to treat patients in reasonable times be technologically achievable at reasonable cost with good reliability, and accelerator space requirements which can be met in a hospital, and finally (4) that the treatment be safe for the patients

  19. An Accelerator Neutron Source for BNCT

    Blue, Thomas, E

    2006-03-14

    The overall goal of this project was to develop an accelerator-based neutron source (ABNS) for Boron Neutron Capture Therapy (BNCT). Specifically, our goals were to design, and confirm by measurement, a target assembly and a moderator assembly that would fulfill the design requirements of the ABNS. These design requirements were 1) that the neutron field quality be as good as the neutron field quality for the reactor-based neutron sources for BNCT, 2) that the patient treatment time be reasonable, 3) that the proton current required to treat patients in reasonable times be technologially achievable at reasonable cost with good reliability, and accelerator space requirements which can be met in a hospital, and finally 4) that the treatment be safe for the patients.

  20. Crystal Driven Neutron Source: A New Paradigm for Miniature Neutron Sources

    Neutron interrogation techniques have specific advantages for detection of hidden, shielded, or buried threats over other detection modalities in that neutrons readily penetrate most materials providing backscattered gammas indicative of the elemental composition of the potential threat. Such techniques have broad application to military and homeland security needs. Present neutron sources and interrogation systems are expensive and relatively bulky, thereby making widespread use of this technique impractical. Development of a compact, high intensity crystal driven neutron source is described. The crystal driven neutron source approach has been previously demonstrated using pyroelectric crystals that generate extremely high voltages when thermal cycled. Placement of a sharpened needle on the positively polarized surface of the pyroelectric crystal results in sufficient field intensification to field ionize background deuterium molecules in a test chamber, and subsequently accelerate the ions to energies in excess of ∼100 keV, sufficient for either D-D or D-T fusion reactions with appropriate target materials. Further increase in ion beam current can be achieved through optimization of crystal thermal ramping, ion source and crystal accelerator configuration. The advantage of such a system is the compact size along with elimination of large, high voltage power supplies. A novel implementation discussed incorporates an independently controlled ion source in order to provide pulsed neutron operation having microsecond pulse width.

  1. Crystal Driven Neutron Source: A New Paradigm for Miniature Neutron Sources

    Tang, V.; Morse, J.; Meyer, G.; Falabella, S.; Guethlein, G.; Kerr, P.; Park, H. G.; Rusnak, B.; Sampayan, S.; Schmid, G.; Spadaccini, C.; Wang, L.

    2009-03-01

    Neutron interrogation techniques have specific advantages for detection of hidden, shielded, or buried threats over other detection modalities in that neutrons readily penetrate most materials providing backscattered gammas indicative of the elemental composition of the potential threat. Such techniques have broad application to military and homeland security needs. Present neutron sources and interrogation systems are expensive and relatively bulky, thereby making widespread use of this technique impractical. Development of a compact, high intensity crystal driven neutron source is described. The crystal driven neutron source approach has been previously demonstrated using pyroelectric crystals that generate extremely high voltages when thermal cycled [1-4]. Placement of a sharpened needle on the positively polarized surface of the pyroelectric crystal results in sufficient field intensification to field ionize background deuterium molecules in a test chamber, and subsequently accelerate the ions to energies in excess of ˜100 keV, sufficient for either D-D or D-T fusion reactions with appropriate target materials. Further increase in ion beam current can be achieved through optimization of crystal thermal ramping, ion source and crystal accelerator configuration. The advantage of such a system is the compact size along with elimination of large, high voltage power supplies. A novel implementation discussed incorporates an independently controlled ion source in order to provide pulsed neutron operation having microsecond pulse width.

  2. Photonic Crystal Laser-Driven Accelerator Structures

    Cowan, Benjamin M.

    2007-08-22

    Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

  3. Update on Proton Driven Plasma Wakefield Acceleration

    Xia, G; Lotov, K; Pukhov, A; Kumar, N; An, W; Lu, W; Mori, W B; Joshi, C; Huang, C; Muggli, P; Assmann, R; Zimmermann, F

    2010-01-01

    In this paper, the update of proton driven plasma wakefield acceleration (PDPWA) is given. After a brief introduction to the scheme of PDPWA, a future demonstration experiment is discussed. The particle-in-cell simulation results based on the realistic proton beams from the CERN Super Proton Synchrotron (SPS) are presented, followed by a simulation study of proton bunch compression. Presented at AAC’10, 13-19 June 2010, Annapolis, MD, USA

  4. Advanced Computational Models for Accelerator-Driven Systems

    In the nuclear engineering scientific community, Accelerator Driven Systems (ADSs) have been proposed and investigated for the transmutation of nuclear waste, especially plutonium and minor actinides. These fuels have a quite low effective delayed neutron fraction relative to uranium fuel, therefore the subcriticality of the core offers a unique safety feature with respect to critical reactors. The intrinsic safety of ADS allows the elimination of the operational control rods, hence the reactivity excess during burnup can be managed by the intensity of the proton beam, fuel shuffling, and eventually by burnable poisons. However, the intrinsic safety of a subcritical system does not guarantee that ADSs are immune from severe accidents (core melting), since the decay heat of an ADS is very similar to the one of a critical system. Normally, ADSs operate with an effective multiplication factor between 0.98 and 0.92, which means that the spallation neutron source contributes little to the neutron population. In addition, for 1 GeV incident protons and lead-bismuth target, about 50% of the spallation neutrons has energy below 1 MeV and only 15% of spallation neutrons has energies above 3 MeV. In the light of these remarks, the transmutation performances of ADS are very close to those of critical reactors.

  5. Dynamic response of an accelerator driven system to accelerator beam interruptions for criticality

    Subcritical nuclear reactors driven by intense neutron sources can be very suitable tools for nuclear waste transmutation, particularly in the case of minor actinides with very low fractions of delayed neutrons. A proper control of these systems needs to know at every time the absolute value of the reactor subcriticality (negative reactivity), which must be measured by fully reliable methods, usually conveying a short interruption of the accelerator beam in order to assess the neutron flux reduction. Those interruptions should be very short in time, for not disturbing too much the thermal magnitudes of the reactor. Otherwise, the cladding and the fuel would suffer from thermal fatigue produced by those perturbations, and the mechanical integrity of the reactor would be jeopardized. It is shown in this paper that beam interruptions of the order of 400 μs repeated every second would not disturb significantly the reactor thermal features, while enabling for an adequate measurement of the negative reactivity

  6. Radiological Impact of the TRIGA Accelerator-Driven Experiment (TRADE)

    Herrera-Martínez, A; Kadi, Y; Zanini, L; Parks, G T; Rubbia, Carlo; Burgio, N; Carta, M; Santagata, A; Cinotti, L

    2002-01-01

    The TRADE project, which is part of the European Roadmap towards the development of Accelerator Driven Systems (ADS), foresees the coupling of a 110 MeV, 2 mA proton cyclotron with the core of a 1 MW Triga research reactor. We performed radioprotection studies using two state-of-the-art computer code packages, FLUKA and EA-MC. We concentrated on the calculation of the neutron and particle flux and dose rates during normal operation as well as in the case of several possible accidents, in order to assess the radiation damage and define the design of key components of the facility, such as the beam-line shielding. Both high-energy particle interactions and low-energy neutron transport are treated with a sophisticated method based on a full Monte Carlo simulation, combined with the use of modern nuclear data libraries.

  7. Observation of Neutron Skyshine from an Accelerator Based Neutron Source

    Franklyn, C. B.

    2011-12-01

    A key feature of neutron based interrogation systems is the need for adequate provision of shielding around the facility. Accelerator facilities adapted for fast neutron generation are not necessarily suitably equipped to ensure complete containment of the vast quantity of neutrons generated, typically >1011 nṡs-1. Simulating the neutron leakage from a facility is not a simple exercise since the energy and directional distribution can only be approximated. Although adequate horizontal, planar shielding provision is made for a neutron generator facility, it is sometimes the case that vertical shielding is minimized, due to structural and economic constraints. It is further justified by assuming the atmosphere above a facility functions as an adequate radiation shield. It has become apparent that multiple neutron scattering within the atmosphere can result in a measurable dose of neutrons reaching ground level some distance from a facility, an effect commonly known as skyshine. This paper describes a neutron detection system developed to monitor neutrons detected several hundred metres from a neutron source due to the effect of skyshine.

  8. Designing of the laser driven dielectric accelerator

    A phase-modulation-masked-type laser-driven dielectric accelerator was studied. Although the preliminary analysis made a conclusion that a grating period and an electron speed must satisfy the matching condition of LG=λ=v=c, a deformation of a wavefront in a transmission grating relaxed the matching condition and enabled the slow electron to be accelerated. The simulation results by using the FDTD code, Meep, showed that the low energy electron of 20 keV felt the acceleration field strength of 20 MV/m and gradually felt higher field as the speed was increased. The ultra relativistic electron felt the field strength of 600 MV/m. The Meep code also showed that a length of the accelerator to get energy of 1 MeV was 3.8 mm, the required laser power and energy were 11 GW and 350 mJ, respectively. Restrictions on the laser was eased by adopting sequential laser pulses. If the accelerator is illuminated by sequential N pulses, the pulse power, pulse width and the pulse energy are reduced to 1=N, 1=N and 1=N2, respectively. The required laser power per pulse is estimated to be 2.2 GW when ten pairs of sequential laser pulse is irradiated. (author)

  9. The Spallation Neutron Source accelerator system design

    Henderson, S., E-mail: stuarth@fnal.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Abraham, W. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Aleksandrov, A. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Allen, C. [Techsource, Inc., 1475 Central Avenue, Suite 250, Los Alamos, NM 87544-3291 (United States); Alonso, J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Anderson, D. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Arenius, D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Arthur, T. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Assadi, S. [Techsource, Inc., 1475 Central Avenue, Suite 250, Los Alamos, NM 87544-3291 (United States); Ayers, J.; Bach, P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Badea, V. [Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-5000 (United States); Battle, R. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Beebe-Wang, J. [Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-5000 (United States); Bergmann, B.; Bernardin, J.; Bhatia, T.; Billen, J.; Birke, T.; Bjorklund, E. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); and others

    2014-11-01

    The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ∼100 high-power RF power systems, a 2 K cryogenic plant, ∼400 DC and pulsed power supply systems, ∼400 beam diagnostic devices and a distributed control system handling ∼100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

  10. Accelerator based steady state neutron source

    Using high current, cw linear accelerator technology, a spallation neutron source can achieve much higher average intensities than existing or proposed pulsed spallation sources. With about 100 mA of 300 MeV protons or deuterons, the accelerator based neutron research facility (ABNR) would initially achieve the 1016 n/cm2s thermal flux goal of the advanced steady state neutron source, and upgrading could provide higher steady state fluxes. The relatively low ion energy compared to other spallation sources has an important impact on R and D requirements as well as capital cost, for which a range of $300-450 M is estimated by comparison to other accelerator-based neutron source facilities. The source is similar to a reactor source is most respects. It has some higher energy neutrons but fewer gamma rays, and the moderator region is free of many of the design constraints of a reactor, which helps to implement sources for various neutron energy spectra, many beam tubes, etc., with the development of a multibeam concept and the basis for currents greater than 100 mA that is assumed in the R and D plan, the ABNR would serve many additional uses, such as fusion materials development, production of proton-rich isotopes, and other energy and defense program needs

  11. An accelerator based steady state neutron source

    Using high current, cw linear accelerator technology, a spallation neutron source can achieve much higher average intensities than existing or proposed pulsed spallation sources. With about 100 mA of 300 MeV protons or deuterons, the accelerator based neutron research facility (ABNR) would initially achieve the 1016 n/cm2 s themal flux goal of the advanced steady state neutron source, and upgrading could provide higher steady state fluxes. The relatively low ion energy compared to other spallation sources has an important impact on R and D requirements as well as capital cost, for which a range of Dollar 300-450 is estimated by comparison to other accelerator-based neutron source facilities. The source is similar to a reactor source in most respects. It has some higher energy neutrons but fewer gamma rays, and the moderator region is free of many of the design constraints of a reactor, which helps to implement sources for various neutron energy spectra, many beam tubes, etc. With the development of a multibeam concept and the basis for currents greater than 100 mA that is assumed in the R and D plan, the ABNR would serve many additional uses, such as fusion materials development, production of proton-rich isotopes, and other energy and defense program needs. (orig.)

  12. Towards the final BSA modeling for the accelerator-driven BNCT facility at INFN LNL

    Some remarkable advances have been made in the last years on the SPES-BNCT project of the Istituto Nazionale di Fisica Nucleare (INFN) towards the development of the accelerator-driven thermal neutron beam facility at the Legnaro National Laboratories (LNL), aimed at the BNCT experimental treatment of extended skin melanoma. The compact neutron source will be produced via the 9Be(p,xn) reactions using the 5 MeV, 30 mA beam driven by the RFQ accelerator, whose modules construction has been recently completed, into a thick beryllium target prototype already available. The Beam Shaping Assembly (BSA) final modeling, using both neutron converter and the new, detailed, Be(p,xn) neutron yield spectra at 5 MeV energy recently measured at the CN Van de Graaff accelerator at LNL, is summarized here.

  13. Towards the final BSA modeling for the accelerator-driven BNCT facility at INFN LNL

    Ceballos, C. [Centro de Aplicaciones Tecnlogicas y Desarrollo Nuclear, 5ta y30, Miramar, Playa, Ciudad Habana (Cuba); Esposito, J., E-mail: juan.esposito@lnl.infn.it [INFN, Laboratori Nazionali di Legnaro (LNL), via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Agosteo, S. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Colautti, P.; Conte, V.; Moro, D. [INFN, Laboratori Nazionali di Legnaro (LNL), via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Pola, A. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2011-12-15

    Some remarkable advances have been made in the last years on the SPES-BNCT project of the Istituto Nazionale di Fisica Nucleare (INFN) towards the development of the accelerator-driven thermal neutron beam facility at the Legnaro National Laboratories (LNL), aimed at the BNCT experimental treatment of extended skin melanoma. The compact neutron source will be produced via the {sup 9}Be(p,xn) reactions using the 5 MeV, 30 mA beam driven by the RFQ accelerator, whose modules construction has been recently completed, into a thick beryllium target prototype already available. The Beam Shaping Assembly (BSA) final modeling, using both neutron converter and the new, detailed, Be(p,xn) neutron yield spectra at 5 MeV energy recently measured at the CN Van de Graaff accelerator at LNL, is summarized here.

  14. Accelerator-driven X-ray Sources

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  15. Target spot localization at neutron producing accelerators

    In the application of neutron producing accelerators it is required to know the actual position and the homogeneity of distribution of the emitted neutrons. Solid state nuclear track detectors offer a good possibility to get precise information on these without any disturbing influence on them. LR 115 2 type cellulose nitrate Kodak-Pathe Foils were irradiated with fast neutrons. When track density is higher than about 104 tracks cm-2 the damaged area can be observed with the naked eye, too. To get quantitative information the track densities were counted with manual technique. (author)

  16. Experimental verification of neutron phenomenology in lead and of transmutation by adiabatic resonance crossing in accelerator driven systems A summary of the TARC Project at CERN

    The Transmutation by Adiabatic Resonance Crossing (TARC) experiment was carried out as PS211 at the CERN PS from 1996 to 1999. Energy and space distributions of spallation neutrons (produced by 2.5 and 3.57 GeV/c CERN proton beams) slowing down in a 3.3x3.3x3 m3 lead volume and neutron capture rates on long-lived fission fragments 99Tc and 129I demonstrate that Adiabatic Resonance Crossing (ARC) can be used to eliminate efficiently such nuclear waste and validate innovative simulation

  17. Experimental verification of neutron phenomenology in lead and of transmutation by adiabatic resonance crossing in accelerator driven systems A summary of the TARC Project at CERN

    Abanades, A.; Aleixandre, J.; Andriamonje, S.; Angelopoulos, A.; Apostolakis, A.; Arnould, H.; Belle, E.; Bompas, C.A.; Brozzi, D.; Bueno, J.; Buono, S.; Carminati, F.; Casagrande, F.; Cennini, P.; Collar, J.I.; Cerro, E.; Moral, R.D.R.Del; Diez, S.; Dumps, L.; Eleftheriadis, C.; Embid, M.; Fernandez, R.; Galvez, J.; Garcia, J.; Geles, C.; Giorni, A.; Gonzalez, E.; Gonzalez, O.; Goulas, I.; Heuer, D.; Hussonnois, M.; Kadi, Y.; Karaiskos, P.; Kitis, G.; Klapisch, R.; Kokkas, P.; Lacoste, V.; Le Naour, C.; Lopez, C.; Loiseaux, J.M.; Martinez-Val, J.M.; Meplan, O.; Nifenecker, H.; Oropesa, J.; Papadopoulos, I.; Pavlopoulos, P.; Perez-Enciso, E.; Perez-Navarro, A.; Perlado, M.; Placci, A.; Poza, M.; Revol, J.-P. E-mail: Jean-Pierre.Revol@cern.ch; Rubbia, C.; Rubio, J.A.; Sakelliou, L.; Saldana, F.; Savvidis, E.; Schussler, F.; Sirvent, C.; Tamarit, J.; Trubert, D.; Tzima, A.; Viano, J.B.; Vieira, S.; Vlachoudis, V.; Zioutas, K

    2001-05-11

    The Transmutation by Adiabatic Resonance Crossing (TARC) experiment was carried out as PS211 at the CERN PS from 1996 to 1999. Energy and space distributions of spallation neutrons (produced by 2.5 and 3.57 GeV/c CERN proton beams) slowing down in a 3.3x3.3x3 m{sup 3} lead volume and neutron capture rates on long-lived fission fragments {sup 99}Tc and {sup 129}I demonstrate that Adiabatic Resonance Crossing (ARC) can be used to eliminate efficiently such nuclear waste and validate innovative simulation.

  18. Laser driven proton acceleration and beam shaping

    Sinigardi, Stefano

    2014-01-01

    In the race to obtain protons with higher energies, using more compact systems at the same time, laser-driven plasma accelerators are becoming an interesting possibility. But for now, only beams with extremely broad energy spectra and high divergence have been produced. The driving line of this PhD thesis was the study and design of a compact system to extract a high quality beam out of the initial bunch of protons produced by the interaction of a laser pulse with a thin solid target, usi...

  19. Plasma driven neutron/gamma generator

    Leung, Ka-Ngo; Antolak, Arlyn

    2015-03-03

    An apparatus for the generation of neutron/gamma rays is described including a chamber which defines an ion source, said apparatus including an RF antenna positioned outside of or within the chamber. Positioned within the chamber is a target material. One or more sets of confining magnets are also provided to create a cross B magnetic field directly above the target. To generate neutrons/gamma rays, the appropriate source gas is first introduced into the chamber, the RF antenna energized and a plasma formed. A series of high voltage pulses are then applied to the target. A plasma sheath, which serves as an accelerating gap, is formed upon application of the high voltage pulse to the target. Depending upon the selected combination of source gas and target material, either neutrons or gamma rays are generated, which may be used for cargo inspection, and the like.

  20. Parametric study of the accelerator-driven transmutation system

    A couple of parametric studies were performed for an accelerator-driven transmutation system in KAERI (Korea Atomic Energy Research Institute). For the analysis, LAHET code system developed by LANL was employed. Molten salt fuel was adopted with its chemical composition of 64NaCl3-1Pu-35MA(Minor Actinide)Cl3. The isotope compositions of Pu and Ma were determined based on the composition in the 10-year cooled spent fuel having 3.2 W% initial enrichment and 33GWD/MTU discharge burnup. Proton beam of 20 mA, 1 GeV was assumed for the neutron production by the spallation reaction with the fuel. The fuel was designed to perform multifunction such as target, coolant. From the calculation results, one proton was believed to produce about 27 neutrons and the neutron multiplication factor was found to be 0.95 for the given system condition. For the beam of 20 mA, 1 GeV, the neutron flux reached up to 1.26x1015 n/cm2 and the corresponding total thermal power was 773 MWth. It was believed that the proposed system could transmute 502 kg of MA a year. 3 refs., 3 figs., 1 tab

  1. Neutron radiation from medical electron accelerators

    A method is described using simple gold foils and relatively inexpensive moderators to measure neutron fluences, both fast nd thermal, which then can be converted to dose equivalent using a few simple formulas. The method is sensitive, easy to calibrate, and should work at most accelerators regardless of energy or room geometry

  2. PRODUCTION AND APPLICATIONS OF NEUTRONS USING PARTICLE ACCELERATORS

    David L. Chichester

    2009-11-01

    Advances in neutron science have gone hand in hand with the development and of particle accelerators from the beginning of both fields of study. Early accelerator systems were developed simply to produce neutrons, allowing scientists to study their properties and how neutrons interact in matter, but people quickly realized that more tangible uses existed too. Today the diversity of applications for industrial accelerator-based neutron sources is high and so to is the actual number of instruments in daily use is high, and they serve important roles in the fields where they're used. This chapter presents a technical introduction to the different ways particle accelerators are used to produce neutrons, an historical overview of the early development of neutron-producing particle accelerators, a description of some current industrial accelerator systems, narratives of the fields where neutron-producing particle accelerators are used today, and comments on future trends in the industrial uses of neutron producing particle accelerators.

  3. Accelerating Science Driven System Design With RAMP

    Wawrzynek, John [Univ. of California, Berkeley, CA (United States)

    2015-05-01

    Researchers from UC Berkeley, in collaboration with the Lawrence Berkeley National Lab, are engaged in developing an Infrastructure for Synthesis with Integrated Simulation (ISIS). The ISIS Project was a cooperative effort for “application-driven hardware design” that engages application scientists in the early parts of the hardware design process for future generation supercomputing systems. This project served to foster development of computing systems that are better tuned to the application requirements of demanding scientific applications and result in more cost-effective and efficient HPC system designs. In order to overcome long conventional design-cycle times, we leveraged reconfigurable devices to aid in the design of high-efficiency systems, including conventional multi- and many-core systems. The resulting system emulation/prototyping environment, in conjunction with the appropriate intermediate abstractions, provided both a convenient user programming experience and retained flexibility, and thus efficiency, of a reconfigurable platform. We initially targeted the Berkeley RAMP system (Research Accelerator for Multiple Processors) as that hardware emulation environment to facilitate and ultimately accelerate the iterative process of science-driven system design. Our goal was to develop and demonstrate a design methodology for domain-optimized computer system architectures. The tangible outcome is a methodology and tools for rapid prototyping and design-space exploration, leading to highly optimized and efficient HPC systems.

  4. A prototype Accelerator Driven System in Belgium: the Myrrha project

    The renewed interest in Accelerator Driven Systems (ADS) world-wide, has given a new increased effort in several related research domains. The communications within the ICANS, ICENES and ADTT meetings have shown that all major research institutes are somehow conducting research in this new field. Within this research forum, most of the e proposed systems deal with spallation sources in the MW-range, addressing needs for accelerators and sub-critical facilities that are out of current reliability and sometimes even out of current technology range. The necessary research in several sub-domains has to be addressed once and will need prototype systems enabling the validation and test of calculational tools and technological items. At SCK.CEN, the Belgian nuclear research center, the Myrrha project has been started end of 1995. This project intends to design, develop and possibly realize a prototype accelerator driven system as advanced neutron source and with four main objectives. . research of ADS-development as an option for transmutation . in-core irradiation experiments as extension and continuing support in the field of reactor physics and technology and safety-related experiments; . medical and industrial applications (including radioisotope production, known as the ADONIS-project) . extension of current SCK.CEn-research and extensions into new fields based on the availability of performing in-core and neutron-beam experiments This paper will describe the current status of this project and planning og ongoing research as well the description of two specific applications, i. e. radioisotope production and transmutation studies. (Author) 10 refs

  5. Accelerator-based neutron radioscopic systems

    There is interest in non-reactor source, thermal neutron inspection systems for applications in aircraft maintenance, explosive devices, investment-cast turbine blades, etc. Accelerator sources, (d-T), RFQ accelerators and cyclotrons as examples, are available for either transportable or fixed neutron inspection systems. Sources are reviewed for neutron output, portability, ease of use and cost, and for use with an electronic neutron imaging camera (image intensifier or scintillator-camera system) to provide a prompt response, neutron inspection system. Particular emphasis is given to the current aircraft inspection problem to detect and characterize corrosion. Systems are analyzed to determine usefulness in providing an on-line inspection technique to detect corrosion in aluminum honeycomb aircraft components, either on-aircraft or in a shop environment. The neutron imaging sensitivity to hydrogenous aluminum corrosion product offers early detection advantages for aircraft corrosion, to levels of aluminum metal loss as small as 25 μm. The practical capability for a continuous scan thermal neutron radioscopic system to inspect up to 500 square feet of component surface per day is used as an evaluation criterion, with the system showing contrast sensitivity of at least 5% and image detail in the order of 4 mm for parts 10 cm thick. Under these practical conditions and 3-shift operation, the source must provide an incident thermal neutron flux of 5.6x104 n cm-2 s-1 at an L/D of 30. A stop and go inspection approach, offering improved resolution, would require a source with similar characteristics

  6. Accelerator Based Neutron Beams for Neutron Capture Therapy

    Yanch, Jacquelyn C.

    2003-04-11

    The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 10(sup 7) W/m(sup 2) with heat transfer coefficients of 10(sup 6)W/m(sup 2)-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and

  7. Accelerator Based Neutron Beams for Neutron Capture Therapy

    The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 10(sup 7) W/m(sup 2) with heat transfer coefficients of 10(sup 6)W/m(sup 2)-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and

  8. Research on accelerator-driven transmutation and studies of experimental facilities

    Takizuka, Takakazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    JAERI is carrying out R and Ds on accelerator-driven transmutation systems under the national OMEGA Program that aims at development of the technology to improve efficiency and safety in the final disposal of radioactive waste. Research facilities for accelerator-driven transmutation experiments are proposed to construct within the framework of the planned JAERI Neutron Science Project. This paper describes the features of the proposed accelerator-driven transmutation systems and their technical issues to be solved. A research facility plan under examination is presented. The plan is divided in two phases. In the second phase, technical feasibility of accelerator-driven systems will be demonstrated with a 30-60 MW experimental integrated system and with a 7 MW high-power target facility. (author)

  9. Radiological Hazard of Spallation Products in Accelerator-Driven System

    The central issue underlying this paper is related to elucidating the hazard of radioactive spallation products that might be an important factor affecting the design option of accelerator-driven systems (ADSs). Hazard analysis based on the concept of Annual Limit on Intake identifies alpha-emitting isotopes of rare earths (REs) (dysprosium, gadolinium, and samarium) as the dominant contributors to the overall toxicity of traditional (W, Pb, Pb-Bi) targets. The matter is addressed from several points of view: code validation to simulate their yields, choice of material for the neutron producing targets, and challenging the beam type. The paper quantitatively determines the domain in which the toxicity of REs exceeds that of polonium activation products broadly discussed now in connection with advertising lead-bismuth technology for the needs of ADSs

  10. Accelerator driven systems from the radiological safety point of view

    P K Sarkar; Maitreyee Nandy

    2007-02-01

    In the proposed accelerator driven systems (ADS) the possible use of several milliamperes of protons of about 1 GeV incident on high mass targets like the molten lead–bismuth eutectic is anticipated to pose radiological problems that have so far not been encountered by the radiation protection community. Spallation reaction products like high energy gammas, neutrons, muons, pions and several radiotoxic nuclides including Po-210 complicate the situation. In the present paper, we discuss radiation safety measures like bulk shielding, containment of radiation leakage through ducts and penetration and induced activity in the structure to protect radiation workers as well as estimation of sky-shine, soil and ground water activation, release of toxic gases to the environment to protect public as per the stipulations of the regulatory authorities. We recommend the application of the probabilistic safety analysis technique by assessing the probability and criticality of different hazard-initiating events using HAZOP and FMECA.

  11. Accelerator-driven Transmutation of Waste

    Venneri, Francesco

    1998-04-01

    Nuclear waste from commercial power plants contains large quantities of plutonium, other fissionable actinides, and long-lived fission products that are potential proliferation concerns and create challenges for the long-term storage. Different strategies for dealing with nuclear waste are being followed by various countries because of their geologic situations and their views on nuclear energy, reprocessing and non-proliferation. The current United States policy is to store unprocessed spent reactor fuel in a geologic repository. Other countries are opting for treatment of nuclear waste, including partial utilization of the fissile material contained in the spent fuel, prior to geologic storage. Long-term uncertainties are hampering the acceptability and eventual licensing of a geologic repository for nuclear spent fuel in the US, and driving up its cost. The greatest concerns are with the potential for radiation release and exposure from the spent fuel for tens of thousands of years and the possible diversion and use of the actinides contained in the waste for weapons construction. Taking advantage of the recent breakthroughs in accelerator technology and of the natural flexibility of subcritical systems, the Accelerator-driven Transmutation of Waste (ATW) concept offers the United States and other countries the possibility to greatly reduce plutonium, higher actinides and environmentally hazardous fission products from the waste stream destined for permanent storage. ATW does not eliminate the need for, but instead enhances the viability of permanent waste repositories. Far from being limited to waste destruction, the ATW concept also brings to the table new technologies that could be relevant for next-generation power producing reactors. In the ATW concept, spent fuel would be shipped to the ATW site where the plutonium, transuranics and selected long-lived fission products would be destroyed by fission or transmutation in their first and only pass through the

  12. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    A small scale experiment designed to demonstrate many of the aspects of accelerator-driven transmutation technology is described. The experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator to produce neutrons with a molten Lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate Plutonium burning or transmutation of commercial spent fuel or energy production from Thorium

  13. A New Type of Plasma Wakefield Accelerator Driven by Magnetowaves

    Chen, Pisin(Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, 10617, Taipei, Taiwan); Chang, Feng-Yin; Lin, Guey-Lin; Noble, Robert J.; Sydora, Richard

    2008-01-01

    We present a new concept for a plasma wakefield accelerator driven by magnetowaves (MPWA). This concept was originally proposed as a viable mechanism for the "cosmic accelerator" that would accelerate cosmic particles to ultra high energies in the astrophysical setting. Unlike the more familiar Plasma Wakefield Accelerator (PWFA) and the Laser Wakefield Accelerator (LWFA) where the drivers, the charged-particle beam and the laser, are independently existing entities, MPWA invokes the high-fre...

  14. A steady-state core analysis code for the modeling of accelerator-driven subcritical reactors

    In order to analyze and evaluate Accelerator Driven Subcritical Reactors (ADSR) efficiently, a neutronics/thermal-hydraulics coupling analysis code named LAVENDER has been developed. In the neutronics calculation, the three dimensional deterministic neutron transport method is adopted. The nuclides transmutation analysis is implemented by the micro-depletion method with the Transmutation Trajectory Analysis algorithm (TTA). In the thermal-hydraulics calculation, a heat transfer model is established to consider thermal feedback and examine thermal-hydraulics design. The validations are performed based on several benchmarks. Numerical results indicate that LAVENDER is reliable and efficient to be applied for the design and steady-state analysis of ADSR. (author)

  15. Experimental Results on the First Short Pulse Laser Driven Neutron Source Powerful Enough For Applications In Radiography

    Guler, Nevzat

    2012-10-01

    Short pulse laser driven neutron source can be a compact and relatively cheap way to produce neutrons with energies in excess of 10 MeV. It is based on short pulse laser driven ions interacting with a converter material to produce neutrons via separation or breakup mechanisms. Previous research on the short pulse laser driven ion acceleration has mainly concentrated on surface acceleration mechanisms, which typically yield isotropic emission of neutrons from the converter. Recent experiments performed with a high contrast laser at TRIDENT facility at LANL demonstrated laser driven ion acceleration mechanism based on the concept of relativistic transparency. This produced an intense beam of high energy (up to 80 MeV) deuterons directed into a Be converter to produce a forward peaked neutron flux with a record yield, on the order of 4.4x10^9 n/sr. The produced neutron beam had a pulse duration less than a nanosecond and an energy range between 2-80 MeV, peaking around 12 MeV. The neutrons in the energy range of 2.5 to 15 MeV were selected by the gated neutron imager to radiograph tungsten blocks of different thicknesses. We will present the results from the two acceleration mechanisms and the first short pulse laser generated neutron radiograph.

  16. On the use of WIMS-7 for calculations on accelerator-driven systems

    De Kruijff, W.J.M.; Freudenreich, W.J.M

    1998-02-01

    The WIMS-7 code package has successfully been applied for a simple benchmark of a lead-cooled accelerator-driven system (ADS). With WIMS-7 it is possible to model a fixed source and to calculate the multiplication in a subcritical system. The calculations have shown that WIMS-7 is capable of treating this benchmark of a homogenized lead-cooled system with a fast neutron spectrum. The results described in this report are very promising and stimulate further investigation of WIMS-7 to study ADS-applications and lead-cooled reactor cores. It is useful to have a more extensive validation of WIMS-7 for lead-cooled ADS. In this report we have only considered a simple homogenized system. In the near future the application of WIMS-7 will be twofold. First, WIMS-7 can be applied to calculate the neutron spectrum in an accelerator-driven system in order to perform transmutation studies with a burnup code. Second, WIMS-7 can be used to study in more detail the neutronics of accelerator-driven systems. This is useful in order to learn more about the physics of accelerator-driven systems. 6 refs.

  17. On the use of WIMS-7 for calculations on accelerator-driven systems

    The WIMS-7 code package has successfully been applied for a simple benchmark of a lead-cooled accelerator-driven system (ADS). With WIMS-7 it is possible to model a fixed source and to calculate the multiplication in a subcritical system. The calculations have shown that WIMS-7 is capable of treating this benchmark of a homogenized lead-cooled system with a fast neutron spectrum. The results described in this report are very promising and stimulate further investigation of WIMS-7 to study ADS-applications and lead-cooled reactor cores. It is useful to have a more extensive validation of WIMS-7 for lead-cooled ADS. In this report we have only considered a simple homogenized system. In the near future the application of WIMS-7 will be twofold. First, WIMS-7 can be applied to calculate the neutron spectrum in an accelerator-driven system in order to perform transmutation studies with a burnup code. Second, WIMS-7 can be used to study in more detail the neutronics of accelerator-driven systems. This is useful in order to learn more about the physics of accelerator-driven systems. 6 refs

  18. Advanced fuel developments for an industrial accelerator driven system prototype

    Delage, Fabienne; Ottaviani, Jean Pierre [Commissariat a l' Energie Atomique CEA (France); Fernandez-Carretero, Asuncion; Staicu, Dragos [JRC-ITU (Germany); Boccaccini, Claudia-Matzerath; Chen, Xue-Nong; Mascheck, Werner; Rineiski, Andrei [Forschungszentrum Karlsruhe - FZK (Germany); D' Agata, Elio [JRC-IE (Netherlands); Klaassen, Frodo [NRG, PO Box 25, NL-1755 ZG Petten (Netherlands); Sobolev, Vitaly [SCK-CEN (Belgium); Wallenius, Janne [KTH Royal Institute of Technology (Sweden); Abram, T. [National Nuclear Laboratory - NNL (United Kingdom)

    2009-06-15

    Fuel to be used in an Accelerator Driven System (ADS) for transmutation in a fast spectrum, can be described as a highly innovative concept in comparison with fuels used in critical cores. ADS fuel is not fertile, so as to improve the transmutation performance. It necessarily contains a high concentration ({approx}50%) of minor actinides and plutonium. This unusual fuel composition results in high gamma and neutron emissions during its fabrication, as well as degraded core performance. So, an optimal ADS fuel is based on finding the best compromise between thermal, mechanical, chemical, neutronic and technological constraints. CERCER and CERMET composite fuels consisting of particles of (Pu,MA)O{sub 2} phases dispersed in a magnesia or molybdenum matrix are under investigation within the frame of the ongoing European Integrated Project EUROTRANS (European Research programme for Transmutation) which aims at performing a conceptual design of a 400 MWth transmuter: the European Facility for Industrial Transmutation (EFIT). Performances and safety of EFIT cores loaded with CERCER and CERMET fuels have been evaluated. Out-of-pile and in-pile experiments are carried out to gain knowledge on the properties and the behaviour of these fuels. The current paper gives an overview of the work progress. (authors)

  19. Transmutation of nuclear waste in accelerator-driven systems

    Herrera-Martínez, A

    2004-01-01

    Today more than ever energy is not only a cornerstone of human development, but also a key to the environmental sustainability of economic activity. In this context, the role of nuclear power may be emphasized in the years to come. Nevertheless, the problems of nuclear waste, safety and proliferation still remain to be solved. It is believed that the use of accelerator-driven systems (ADSs) for nuclear waste transmutation and energy production would address these problems in a simple, clean and economically viable, and therefore sustainable, manner. This thesis covers the major nuclear physics aspects of ADSs, in particular the spallation process and the core neutronics specific to this type of systems. The need for accurate nuclear data is described, together with a detailed analysis of the specific isotopes and energy ranges in which this data needs to be improved and the impact of their uncertainty. Preliminary experimental results for some of these isotopes, produced by the Neutron Time-of-Flight (n_TOF) ...

  20. Estimation and analysis of neutron skyshine at particle accelerators

    This report deals with the neutron dosimetry at the accelerator environment with a special emphasis given to the neutron skyshine problem. Theoretical studies have been carried out for the estimation of neutron skyshine dose using experimentally measured neutron spectra as well as those obtained using theoretically simulated nuclear reaction model calculations. A detailed analysis has been performed with respect to several variables. (author)

  1. Laser Driven Neutron Sources: Characteristics, Applications and Prospects

    Alvarez Ruiz, Jesus; Fernández-Tobias, J.; Mima, K.; Nakai, S; S. Kar; Kato, Y.; Perlado Martin, Jose Manuel

    2012-01-01

    The basics of laser driven neutron sources, properties and possible applications are discussed. We describe the laser driven nuclear processes which trigger neutron generation, namely, nuclear reactions induced by laser driven ion beam (ion n), thermonuclear fusion by implosion and photo-induced nuclear (gamma n) reactions. Based on their main properties, i.e. point source (< 100 μm) and short durations (< ns), different applications are described, such as radiography, time-resolved spe...

  2. The physics of accelerator driven sub-critical reactors

    S B Degweker; Biplab Ghosh; Anil Bajpal; S D Pranjape

    2007-02-01

    In recent years, there has been an increasing worldwide interest in accelerator driven systems (ADS) due to their perceived superior safety characteristics and their potential for burning actinides and long-lived fission products. Indian interest in ADS has an additional dimension, which is related to our planned large-scale thorium utilization for future nuclear energy generation. The physics of ADS is quite different from that of critical reactors. As such, physics studies on ADS reactors are necessary for gaining an understanding of these systems. Development of theoretical tools and experimental facilities for studying the physics of ADS reactors constitute important aspect of the ADS development program at BARC. This includes computer codes for burnup studies based on transport theory and Monte Carlo methods, codes for studying the kinetics of ADS and sub-critical facilities driven by 14 MeV neutron generators for ADS experiments and development of sub-criticality measurement methods. The paper discusses the physics issues specific to ADS reactors and presents the status of the reactor physics program and some of the ADS concepts under study.

  3. Disposition of nuclear waste using subcritical accelerator-driven systems

    Spent fuel from nuclear power plants contains large quantities of Pu, other actinides, and fission products (FP). This creates challenges for permanent disposal because of the long half-lives of some isotopes and the potential for diversion of the fissile material. Two issues of concern for the US repository concept are: (1) long-term radiological risk peaking tens-of-thousands of years in the future; and (2) short-term thermal loading (decay heat) that limits capacity. An accelerator-driven neutron source can destroy actinides through fission, and can convert long-lived fission products to shorter-lived or stable isotopes. Studies over the past decade have established that accelerator transmutation of waste (ATW) can have a major beneficial impact on the nuclear waste problem. Specifically, the ATW concept the authors are evaluating: (1) destroys over 99.9% of the actinides; (2) destroys over 99.9% of the Tc and I; (3) separates Sr-90 and Cs-137; (4) separates uranium from the spent fuel; (5) produces electric power

  4. Disposition of nuclear waste using subcritical accelerator-driven systems

    Venneri, F.; Li, N.; Williamson, M.; Houts, M.; Lawrence, G.

    1998-12-31

    Spent fuel from nuclear power plants contains large quantities of Pu, other actinides, and fission products (FP). This creates challenges for permanent disposal because of the long half-lives of some isotopes and the potential for diversion of the fissile material. Two issues of concern for the US repository concept are: (1) long-term radiological risk peaking tens-of-thousands of years in the future; and (2) short-term thermal loading (decay heat) that limits capacity. An accelerator-driven neutron source can destroy actinides through fission, and can convert long-lived fission products to shorter-lived or stable isotopes. Studies over the past decade have established that accelerator transmutation of waste (ATW) can have a major beneficial impact on the nuclear waste problem. Specifically, the ATW concept the authors are evaluating: (1) destroys over 99.9% of the actinides; (2) destroys over 99.9% of the Tc and I; (3) separates Sr-90 and Cs-137; (4) separates uranium from the spent fuel; (5) produces electric power.

  5. Startup transients in accelerator driven systems using CINESP-ADS code

    Accelerator Driven Systems (ADS) are subcritical nuclear reactor cores driven by spallation neutron source. These spallation neutrons are provided from the bombardment of a liquid metal flowing in a central region of the core, by a proton beam coming from a linear accelerator. Since neutron source dominates the neutronic of the ADS, its control usually is not related to the delayed neutron fractions as in the critical systems. In this way, ADS kinetics diverges from the former ones. This work presents some results of transients in ADS. Since ADS is to work in a pulsed regime, with time duration of pulse, a parametric result is showed to point out that different pulse durations should be studied in conjunction with pulse intensity, to maintain the ADS power stable. In addition, before generating these results, some transients were used to validate the CINESP-ADS code. It solves numerically the kinetic equations based on the multigroup diffusion theory, in one- or two-dimensional, in the Cartesian or Cylindrical geometries, and for any energy and delayed neutron groups. Three-dimensional simulation is possible using a reactor transversal buckling. The numerical solution is obtained via finite differences for the spatial discretization, using the so-called box integration, and with the use of Alternating Direction Explicit (ADE) methods, for the time discretization. The code application to some transients due to source neutron variations demonstrates its efficiency and accuracy, when compared with analytical techniques, such as one that uses expansion in series of Helmholtz eigenfunctions. (author)

  6. Investigation of Lead Target Nuclei Used on Accelerator-Driven Systems for Tritium Production

    Tel, E.; Aydin, A.

    2012-02-01

    High-current proton accelerators are being researched at Los Alamos National Laboratory and other laboratories for accelerator production of tritium, transmuting long-lived radioactive waste into shorter-lived products, converting excess plutonium, and producing energy. These technologies make use of spallation neutrons produced in ( p,xn) and ( n,xn) nuclear reactions on high-Z targets. Through ( p,xn) and ( n,xn) nuclear reactions, neutrons are produced and are moderated by heavy water. These moderated neutrons are subsequently captured on 3He to produce tritium via the ( n,p) reaction. Tritium self-sufficiency must be maintained for a commercial fusion power plant. Rubbia succeeded in a proposal of a full scale demonstration plant of the Energy Amplifier. This plant is to be known the accelerator-driven system (ADS). The ADS can be used for production of neutrons in spallation neutron source and they can act as an intense neutron source in accelerator-driven subcritical reactors, capable of incinerating nuclear waste and of producing energy. Thorium and Uranium are nuclear fuels and Lead, Bismuth, Tungsten are the target nuclei in these reactor systems. The spallation targets can be Pb, Bi, W, etc. isotopes and these target material can be liquid or solid. Naturally Lead includes the 204Pb (%1.42), 206Pb (%24.1), 207Pb (%22.1) and 208Pb (%52.3) isotopes. The design of ADS systems and also a fusion-fission hybrid reactor systems require the knowledge of a wide range of better data. In this study, by using Hartree-Fock method with an effective nucleon-nucleon Skyrme interactions rms nuclear charge radii, rms nuclear mass radii, rms nuclear proton, neutron radii and neutron skin thickness were calculated for the 204, 206, 208Pb isotopes . The calculated results have been compared with those of the compiled experimental and theoretical values of other studies.

  7. First order Fermi acceleration driven by magnetic reconnection

    Drury, Luke O'C

    2012-01-01

    A box model is used to study first order Fermi acceleration driven by magnetic reconnection. It is shown, at least in this simple model, that the spectral index of the accelerated particles is related to the total compression in the same way as in diffusive shock acceleration and is not, as has been suggested, a universal $E^{-5/2}$ spectrum. The acceleration time-scale is estimated and some comments made about the applicability of the process.

  8. Design of an accelerator-driven system for the destruction of nuclear waste

    Progress in particle accelerator technology makes it possible to use a proton accelerator to produce energy and to destroy nuclear waste efficiently. The Energy Amplifier (EA) proposed by Carlo Rubbia and his group is a sub-critical fast neutron system driven by a proton accelerator. It is particularly attractive for destroying, through fission, transuranic elements produced by present nuclear reactors. The EA could also transform efficiently and at minimal cost long-lived fission fragments using the concept of Adiabatic Resonance Crossing (ARC) recently tested at CERN with the TARC experiment. (author)

  9. Generation of nanosecond neutron pulses in vacuum accelerating tubes

    Didenko, A. N.; Shikanov, A. E.; Rashchikov, V. I.; Ryzhkov, V. I.; Shatokhin, V. L.

    2014-06-01

    The generation of neutron pulses with a duration of 1-100 ns using small vacuum accelerating tubes is considered. Two physical models of acceleration of short deuteron bunches in pulse neutron generators are described. The dependences of an instantaneous neutron flux in accelerating tubes on the parameters of pulse neutron generators are obtained using computer simulation. The results of experimental investigation of short-pulse neutron generators based on the accelerating tube with a vacuum-arc deuteron source, connected in the circuit with a discharge peaker, and an accelerating tube with a laser deuteron source, connected according to the Arkad'ev-Marx circuit, are given. In the experiments, the neutron yield per pulse reached 107 for a pulse duration of 10-100 ns. The resultant experimental data are in satisfactory agreement with the results of computer simulation.

  10. Thorium utilization in heavy water moderated Accelerator Driven Systems

    Research on Accelerator Driven Systems (ADSs) is being carried out around the world primarily with the objective of waste transmutation. Presently, the volume of waste in India is small and therefore there is little incentive to develop ADS based waste transmutation technology immediately. With limited indigenous U availability and the presence of large Th deposits in the country, there is a clear incentive to develop Th related technologies. India also has vast experience in design, construction and operation of heavy water moderated reactors. Heavy water moderated reactors employing solid Th fuels can be self sustaining, but the discharge burnups are too low to be economical. A possible way to improve the performance such reactors is to use an external neutron source as is done in ADS. This paper discusses our studies on Th utilization in heavy water moderated ADSs. The study is carried out at the lattice level. The time averaged k-infinity of the Th bundle from zero burnup up to the discharge burnup is taken to be the same as the core (ensemble) averaged k-infinity. For the purpose of the analysis we have chosen standard PHWR and AHWR assemblies. Variation of the pitch and coolant (H2O/D2O) are studied. Both, the once through cycle and the recycling option are studied. In the latter case the study is carried out for various enrichments (% 233U in Th) of the recycled Th fuel bundles. The code DTF as modified for lattice and burnup calculations (BURNTRAN) was used for carrying out the study. The once through cycle represents the most attractive ADS concept (Th burner ADS) possible for Th utilization. It avoids reprocessing of Th spent fuel and in the ideal situation the use of any fissile material either initially or for sustaining itself. The gain in this system is however rather low requiring a high power accelerator and a substantial fraction of the power generated to be fed back to the accelerator. The self sustaining Th-U cycle in a heavy moderated ADS is a

  11. Passive neutron dosemeter-spectrometer for high-energy accelerators

    A passive neutron dosemeter-spectrometer (PNDS) with fission fragments converters is described. The results obtained show that it is a convenient and reliable instrument for neutron dose equivalent measurement in the calibration performing and response investigations of personnel dosemeters in mixed radiation fields behind accelerator shielding. Because of the possibility of neutron spectrum estimation in a wide energy range PNDS using is promissing in the neutron radiation fields research and also as an accidental neutron dosemeter. 23 refs.; 10 figs.; 4 tabs

  12. Simulation of accelerator-driven systems

    The neutronic calculations presented in this paper are a result of a state-of-the-art computer code package developed by the EET group at CERN. Both high-energy particle interactions and low-energy neutron transport are treated with a sophisticated method based on a full Monte Carlo simulation, together with modem nuclear data libraries. The code is designed to run both on parallel and scalar computers. A series of experiments carried out at the CERN-PS (i) confirmed that the spallation process is correctly predicted and (ii) validated the reliability of the predictions of the integral neutronic parameters of the Energy Amplifier Demonstration Facility. (author)

  13. Status of Accelerator Driven Systems Research and Technology Development

    One of the greatest challenges for nuclear energy is how to properly manage the highly radioactive waste generated during irradiation in nuclear reactors. In order for nuclear power to exploit its full potential as a major sustainable energy source, there needs to be a safe and effective way to deal with this waste. Since 1995, several scenario studies have been conducted on different advanced nuclear fuel cycle and waste management options in various countries. Examples include the collaborative projects under “Global sustainable nuclear energy scenarios for long term development and deployment of nuclear energy” of the IAEA International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) initiative, and the scenario studies conducted under the auspices of the OECD Nuclear Energy Agency and the Euratom research project PATEROS — Partitioning and Transmutation European Roadmap for Sustainable Nuclear Energy. Some of the proposed long term nuclear fuel cycles include an innovative concept of a hybrid system for the transmutation of long lived radioisotopes. This is usually the called accelerator driven system (ADS) — or accelerator driven transmutation of waste (ATW) — and consists of a high power proton accelerator, a heavy metal spallation target that produces neutrons when bombarded by the high power beam, and a subcritical core that is neutronically coupled to the spallation target. The ADS, which has been developed in different countries for more than 40 years, is claimed to offer new prospects and advantages for the transmutation of high level radioactive waste. The ADS would convert highly radioactive material to non-radioactive material or material with a much shorter half-life. In addition, these hybrid systems can generate electricity during the conversion of transuranic waste. In 1997, under the guidance of its Technical Working Group on Fast Reactors (TWG-FR), the IAEA published IAEA-TECDOC-985, Accelerator Driven Systems: Energy

  14. High power radiation guiding systems for laser driven accelerators

    This paper reviews the main problems encountered in the design of an optical system for transmitting high fluence radiation in a laser driven accelerator. Particular attention is devoted to the analysis of mirror and waveguide systems. (orig.)

  15. High intensity laser-driven ion acceleration

    Ion acceleration by intense laser-plasma interactions is a very active field of research whose development can be traced in a large number of publications over the last few years. Past studies were mostly performed irradiating thin foils where protons are predominantly accelerated to energies up to 60 MeV in an exponentially decaying spectrum by a mechanism named target normal sheath acceleration (TNSA). We present our latest experimental advances on acceleration schemes away from TNSA, such as shock acceleration, ion beam generation from relativistically transparent targets and radiation-pressure acceleration. These results are a major step towards highly energetic, mono-chromatic ion beams generated at high conversion efficiencies as demanded by many potential applications. Those include fast ignition inertial confinement fusion (ICF) as well as oncology and radiation therapy of tumors.

  16. Study of a multi-beam accelerator driven thorium reactor

    The primary advantages that accelerator driven systems have over critical reactors are: (1) Greater flexibility regarding the composition and placement of fissile, fertile, or fission product waste within the blanket surrounding the target, and (2) Potentially enhanced safety brought about by operating at a sufficiently low value of the multiplication factor to preclude reactivity induced events. The control of the power production can be achieved by vary the accelerator beam current. Furthermore, once the beam is shut off the system shuts down. The primary difference between the operation of an accelerator driven system and a critical system is the issue of beam interruptions of the accelerator. These beam interruptions impose thermo-mechanical loads on the fuel and mechanical components not found in critical systems. Studies have been performed to estimate an acceptable number of trips, and the value is significantly less stringent than had been previously estimated. The number of acceptable beam interruptions is a function of the length of the interruption and the mission of the system. Thus, for demonstration type systems and interruption durations of 1sec 5mins 2500/yr and 50/yr are deemed acceptable. However, for industrial scale power generation without energy storage type systems and interruption durations of t 5mins, the acceptable number of interruptions are 25000, 2500, 250, and 3 respectively. However, it has also been concluded that further development is required to reduce the number of trips. It is with this in mind that the following study was undertaken. The primary focus of this study will be the merit of a multi-beam target system, which allows for multiple spallation sources within the target/blanket assembly. In this manner it is possible to ameliorate the effects of sudden accelerator beam interruption on the surrounding reactor, since the remaining beams will still be supplying source neutrons. The proton beam will be assumed to have an

  17. System and safety studies of accelerator driven transmutation systems. Annual report 1999

    In 1996, SKB commenced funding of the project 'System and safety studies of accelerator driven transmutation systems and development of a spallation target'. The aim of the project was stated as: Development of a complete code for simulation of transmutation processes in an accelerator driven system. Application of the code for analysis of neutron flux, transmutation rates, reactivity changes, toxicity and radiation damages in the transmutation core. Build up of competence regarding issues related to spallation targets, development of research activities regarding relevant material issues. Performing of basic experiments in order to investigate the adequacy of using the spallation. target as a neutron source for a transmutation system, and participation in the planning and implementation of an international demonstration experiment. In the present report, activities within and related to the framework of the project, performed at the department of Nuclear and Reactor Physics at the Royal Institute of Technology during 1999, are accounted for

  18. Power spectral analysis for a subcritical reactor system driven by a pulsed spallation neutron source

    A series of power spectral analyses for a thermal subcritical reactor system driven by a pulsed spallation neutron source was carried out at Kyoto University Critical Assembly (KUCA), to determine the prompt-neutron decay constant of the Accelerator-Driven System (ADS). High-energy protons (100 MeV) obtained from the fixed field alternating gradient accelerator were injected onto a lead-bismuth target, whereby the spallation neutrons were generated. In the cross-power spectral density between time-sequence signal data of two neutron detectors, many delta-function-like peaks at the integral multiple of pulse repetition frequency could be observed. However, no continuous reactor-noise component could be measured. This is because these detectors have too high count-rate to be placed closely to the core. From the point data of these delta-function-like peaks, the prompt-neutron decay constant could be determined. At a slightly subcritical state, the decay constant was consistent with that obtained by a previous power spectral analysis for a pulsed 14 MeV neutron source and by a pulsed neutron experiment. At another deeply subcritical state, however, the present analysis leads to an underestimate of the decay constant. (author)

  19. Choosing the optimal parameters of subcritical reactors driven by accelerators

    Physical aspects of a subcritical Nuclear Power Plants (NPP) driven by proton accelerators are considered. Estimated theoretical calculations are made for subcritical regimes of various types of reactors. It was shown that the creation of the quite effective explosion-safe NPP is real at an existing level of the accelerator technique by using available reactor units (including the serial ones). (author)

  20. Beam-driven, Plasma-based Particle Accelerators

    Muggli, P

    2016-01-01

    We briefly give some of the characteristics of the beam-driven, plasma-based particle accelerator known as the plasma wakefield accelerator (PWFA). We also mention some of the major results that have been obtained since the birth of the concept. We focus on high-energy particle beams where possible.

  1. Application of gas-cooled Accelerator Driven System (ADS) transmutation devices to sustainable nuclear energy development

    Abánades, A.; Garcia Hernandez, Carlos Rafael; GARCÍA FAJARDO, LAURA; Escrivá, A.; Pérez-Navarro Gómez, Ángel; Rosales, J.

    2011-01-01

    The conceptual design of a pebble bed gas-cooled transmutation device is shown with the aim to evaluate its potential for its deployment in the context of the sustainable nuclear energy development, which considers high temperature reactors for their operation in cogeneration mode, producing electricity, heat and Hydrogen. As differential characteristics our device operates in subcritical mode, driven by a neutron source activated by an accelerator that adds clear safety advantages and fuel f...

  2. Application of gas-cooled Accelerator Driven System (ADS) transmutation devices to sustainable nuclear energy development

    Abánades Velasco, Alberto; C. García; García, L.; Escrivá, A.; Pérez-Navarro, A.; Rosales, J.

    2011-01-01

    The conceptual design of a pebble bed gas-cooled transmutation device is shown with the aim to evaluate its potential for its deployment in the context of the sustainable nuclear energy development, which considers high temperature reactors for their operation in cogeneration mode, producing electricity, heat and Hydrogen. As differential characteristics our device operates in subcritical mode, driven by a neutron source activated by an accelerator that adds clear safety advantages and fu...

  3. Disposition of Nuclear Waste Using Subcritical Accelerator-Driven Systems

    Doolen, G.D.; Venneri, F.; Li, N.; Williamson, M.A.; Houts, M.; Lawrence, G.

    1998-06-27

    ATW destroys virtually all the plutonium and higher actinides without reprocessing the spent fuel in a way that could lead to weapons material diversion. An ATW facility consists of three major elements: (1) a high-power proton linear accelerator; (2) a pyrochemical spent fuel treatment i waste cleanup system; (3) a liquid lead-bismuth cooled burner that produces and utilizes an intense source-driven neutron flux for transmutation in a heterogeneous (solid fuel) core. The concept is the result of many years of development at LANL as well as other major international research centers. Once demonstrated and developed, ATW could be an essential part of a global non-proliferation strategy for countries that could build up large quantities of plutonium from their commercial reactor waste. ATW technology, initially proposed in the US, has received wide and rapidly increasing attention abroad, especially in Europe and the Far East with major programs now being planned, organized and tided. Substantial convergence presently exists on the technology choices among the programs, opening the possibility of a strong and effective international collaboration on the phased development of the ATW technology.

  4. Macroscopic multigroup constants for accelerator driven system core calculation

    The high-level wastes stored in facilities above ground or shallow repositories, in close connection with its nuclear power plant, can take almost 106 years before the radiotoxicity became of the order of the background. While the disposal issue is not urgent from a technical viewpoint, it is recognized that extended storage in the facilities is not acceptable since these ones cannot provide sufficient isolation in the long term and neither is it ethical to leave the waste problem to future generations. A technique to diminish this time is to transmute these long-lived elements into short-lived elements. The approach is to use an Accelerator Driven System (ADS), a sub-critical arrangement which uses a Spallation Neutron Source (SNS), after separation the minor actinides and the long-lived fission products (LLFP), to convert them to short-lived isotopes. As an advanced reactor fuel, still today, there is a few data around these type of core systems. In this paper we generate macroscopic multigroup constants for use in calculations of a typical ADS fuel, take into consideration, the ENDF/BVI data file. Four energy groups are chosen to collapse the data from ENDF/B-VI data file by PREPRO code. A typical MOX fuel cell is used to validate the methodology. The results are used to calculate one typical subcritical ADS core. (author)

  5. Design windows for accelerator driven pebble-bed transmutators

    Nuclear waste transmutation can be achieved by different strategies. In this paper, the studies are focused in the 'Once Through' scenario, consisting in the nuclear waste transmutation until a maximum burnup (BU) is achieved. After transmutation, the fuel elements can be disposed in a Deep Storage Facility (DSF.) The main advantage of this strategy is that only one reprocess step is necessary. The drawback of this strategy consists mainly in the need of a fuel element design capable of withstanding very high burn-ups. It has been demonstrated that pebbles fuel elements in a pebble bed reactor design can withstand 700 MWd/Kg BU. This reactor presents the possibility of attainment different neutron spectrum with different fuel element designs, presents good safety characteristics, and the possibility of replacing the fuel elements easily inside the reactor (necessary for recycling strategies.) The transmutation process can be achieved in two steps. The first one, as a critical reactor, and the second one, as a subcritical assembly driven by an accelerator. In this paper, the optimum spectrum for the 'Once Through' strategy is presented, and some safety characteristics of the subcritical assembly are introduced. (authors)

  6. Thorium fuel cycle concept for KAERI's accelerator driven system project

    Korea Atomic Energy Research Institute (KAERI) has been carrying out accelerator driven system related research and development called HYPER for transmutation and energy production. HYPER program is aiming to develop the elemental technologies for the subcritical system by 2001 and build a small bench scale test facility (∼5MW(th)) by the year 2006. Some major features of HYPER have been developed and employed, which are on-power fueling concepts, a hollow cylinder-type metal fuel, and Pb-Bi as a coolant and spallation target material. Another fuel cycle concept for HYPER has been also studied to utilize thorium as a molten salt form to produce electricity as well as to transmute TRU elements. At the early stage of the fuel cycle, fissile plutonium isotopes in TRU will be incinerated to produce energy and to breed 233U from thorium. Preliminary calculation showed that periodic removal of fission products and small amount of TRU addition could maintain the criticality without separation of 233Pa. At the end of the fuel cycle, the composition of fissile plutonium isotopes in TRU was significantly reduced from about 60% to 18%, which is not attractive any more for the diversion of plutonium. Thorium molten salt fuel cycle may be one of the alternative fuel cycles for the transmutation of TRU. The TRU remained at the end of fuel cycle can be incinerated in HYPER having fast neutron spectrums. (author)

  7. Current status of research and development of reactor noise analysis for accelerator-driven subcritical system

    This report presents a current status of the research and development of reactor noise analyses applicable to accelerator-driven subcritical reactor system. These research activities have been concentrated on the Feynman-α neutron correlation analysis on time domain and the power spectral analysis on frequency domain. At present, the latter power spectral analysis is of greater advantage than the former Feynman-α one, for periodic and pulsed neutron source. While Feynman-α formula for pulsed neutron source is too complicated to be fitted directly to variance-to-mean ratio data, the power spectral analysis has a simpler formula based on the first-order reactor transfer function. The Feynman-α should be improved to consider spatial effect of deeply subcritical system and instability of accelerator operation. Further subject of reactor noise analyses is an improvement for high power operation. (author)

  8. Laser-driven wakefield electron acceleration and associated radiation sources

    The first part of this research thesis introduces the basic concepts needed for the understanding of the laser-driven wakefield acceleration. It describes the properties of the used laser beams and plasmas, presents some notions about laser-plasma interactions for a better understanding of the physics of laser-driven acceleration. The second part deals with the numerical modelling and the presentation of simulation tools needed for the investigation of laser-induced wakefield acceleration. The last part deals with the optical control of the injection, a technique analogous to the impulsion collision scheme

  9. Study on variance-to-mean method as subcriticality monitor for accelerator driven system operated with pulse-mode

    Two types of the variance-to-mean methods for the subcritical system that was driven by the periodic and pulsed neutron source were developed and their experimental examination was performed with the Kyoto University Critical Assembly and a pulsed neutron generator. As a result, it was demonstrated that the prompt neutron decay constant could be measured by these methods. From this fact, it was concluded that the present variance-to-mean methods had potential for being used in the subcriticality monitor for the future accelerator driven system operated with the pulse-mode. (author)

  10. Operation and reactivity measurements of an accelerator driven subcritical TRIGA reactor

    O'Kelly, David Sean

    Experiments were performed at the Nuclear Engineering Teaching Laboratory (NETL) in 2005 and 2006 in which a 20 MeV linear electron accelerator operating as a photoneutron source was coupled to the TRIGA (Training, Research, Isotope production, General Atomics) Mark II research reactor at the University of Texas at Austin (UT) to simulate the operation and characteristics of a full-scale accelerator driven subcritical system (ADSS). The experimental program provided a relatively low-cost substitute for the higher power and complexity of internationally proposed systems utilizing proton accelerators and spallation neutron sources for an advanced ADSS that may be used for the burning of high-level radioactive waste. Various instrumentation methods that permitted ADSS neutron flux monitoring in high gamma radiation fields were successfully explored and the data was used to evaluate the Stochastic Pulsed Feynman method for reactivity monitoring.

  11. Preliminary physics design of accelerator-driven thorium cycle fast breeder reactor

    A preliminary reactor physics design of a lead cooled fast accelerator-driven system has been explored as a thorium-uranium cycle breeder reactor. The sub-critical reactor core operates at an effective neutron multiplication factor of 0.95 and when driven by 1 GeV proton beams of intensity 30 mA, produces about ∼ 900 MWth power. Variation of total thermal power, 233U inventory, Keff, radial and axial power distribution through the operating cycle as well as breeding ratio and doubling time are presented. (author)

  12. Results from Accelerator Driven TRIGA Reactor Experiments at The University of Texas at Austin

    Accelerator Driven Transmutation of High-Level Waste (ATW) is one possible solution to the fuel reprocessing back-end problem for the disposal of high level waste such as minor actinides (Am, Np or Cm) and long-lived fission products. International programs continue to support research towards the eventual construction and operation of a proton accelerator driven spallation neutron source coupled to a subcritical 'neutron amplifier' for more efficient HLW transmutation. This project was performed under DOE AFCI Reactor-Accelerator Coupling Experiments (RACE). A 20 MeV Electron Linac was installed in the BP no 5 cave placing neutron source adjacent to an offset reactor core to maximize neutron coupling with available systems. Asymmetric neutron injection 'wasted' neutrons due to high leakage but sufficient neutrons were available to raise reactor power to ∼100 watts. The Linac provided approximately 100 mA but only 50% reached target. The Linac cooling system could not prevent overheating at frequencies over 200 Hz. The Linac electron beam had harmonics of primary frequency and periodic low frequency pulse intensity changes. Neutron detection using fission chambers in current mode eliminated saturation dead time and produced better sensitivity. The Operation of 'dual shielded' fission chambers reduced electron noise from linac. Benchmark criticality calculation using start-up data showed that the MCNPX model overestimates reactivity. TRIGA core was loaded to just slightly supercritical by adding graphite elements and measuring reactivity of $0.037. MCNPX modeled TRIGA core with and without graphite to arrive at 'true' measured subcritical multiplication of 0.998733± 0.00069. Thus, Alpha for the UT-RACE TRIGA core was approximately 155.99 s-1. The Stochastic Feynman-Alpha Method (SFM) accuracy was evaluated during transients and reactivity changes. SFM was shown to be a potential real-time method of reactivity determination in future ADSS but requires stable

  13. Intense laser driven collision-less shock and ion acceleration in magnetized plasmas

    Mima, K.; Jia, Q.; Cai, H. B.; Taguchi, T.; Nagatomo, H.; Sanz, J. R.; Honrubia, J.

    2016-05-01

    The generation of strong magnetic field with a laser driven coil has been demonstrated by many experiments. It is applicable to the magnetized fast ignition (MFI), the collision-less shock in the astrophysics and the ion shock acceleration. In this paper, the longitudinal magnetic field effect on the shock wave driven by the radiation pressure of an intense short pulse laser is investigated by theory and simulations. The transition of a laminar shock (electro static shock) to the turbulent shock (electromagnetic shock) occurs, when the external magnetic field is applied in near relativistic cut-off density plasmas. This transition leads to the enhancement of conversion of the laser energy into high energy ions. The enhancement of the conversion efficiency is important for the ion driven fast ignition and the laser driven neutron source. It is found that the total number of ions reflected by the shock increases by six time when the magnetic field is applied.

  14. Bright Laser-Driven Neutron Source Based on the Relativistic Transparency of Solids

    Roth, M.; Jung, D.; Falk, K.; Guler, N.; Deppert, O.; Devlin, M.; Favalli, A.; Fernandez, J.; Gautier, D.; Geissel, M.; Haight, R.; Hamilton, C. E.; Hegelich, B. M.; Johnson, R. P.; Merrill, F.; Schaumann, G.; Schoenberg, K.; Schollmeier, M.; Shimada, T.; Taddeucci, T.; Tybo, J. L.; Wagner, F.; Wender, S. A.; Wilde, C. H.; Wurden, G. A.

    2013-01-01

    Neutrons are unique particles to probe samples in many fields of research ranging from biology to material sciences to engineering and security applications. Access to bright, pulsed sources is currently limited to large accelerator facilities and there has been a growing need for compact sources over the recent years. Short pulse laser driven neutron sources could be a compact and relatively cheap way to produce neutrons with energies in excess of 10 MeV. For more than a decade experiments have tried to obtain neutron numbers sufficient for applications. Our recent experiments demonstrated an ion acceleration mechanism based on the concept of relativistic transparency. Using this new mechanism, we produced an intense beam of high energy (up to 170 MeV) deuterons directed into a Be converter to produce a forward peaked neutron flux with a record yield, on the order of 1010n/sr. We present results comparing the two acceleration mechanisms and the first short pulse laser generated neutron radiograph.

  15. Magnetically-driven crustquakes in neutron stars

    Lander, S. K.; Andersson, N; Antonopoulou, D.; Watts, A. L.

    2014-01-01

    Crustquake events may be connected with both rapid spin-up `glitches' within the regular slowdown of neutron stars, and high-energy magnetar flares. We argue that magnetic field decay builds up stresses in a neutron star's crust, as the elastic shear force resists the Lorentz force's desire to rearrange the global magnetic-field equilibrium. We derive a criterion for crust-breaking induced by a changing magnetic-field configuration, and use this to investigate strain patterns in a neutron sta...

  16. MYRRHA: a multipurpose accelerator driven system for research and development

    SCK-CEN, the Belgian Nuclear Research Centre, and IBA s.a., Ion Beam Application, a world leader in accelerator technology, want to fulfil a prominent role in the Accelerator Driven Systems field and are designing an ADS prototype, the MYRRHA Project, and conducting an associated R and D programme. The partners are foreseeing MYRRHA as a first step towards the European ADS-Demo facility. The project focuses primarily on ADS related research, i.e. structural materials and nuclear fuel research, liquid metals and associated aspects, sub-critical reactor physics and subsequently on applications such as waste transmutation, radioisotope production and safety research on sub-critical systems. In this respect, the MYRRHA system should become a new major research infrastructure for the European partners presently involved in the ADS Demo development, supporting and enabling the international R and D programs. Ion Beam Applications, the Belgium world leader in particle accelerators, had joined the MYRRHA Project to perform the accelerator development. Currently the study and preliminary conceptual design of the MYRRHA system is going on and an intensive R and D programme is conducted to assess the most risky points of the present design. This study will define the final choice of the characteristics of the facility depending on the selected fields of application to be achieved. The MYRRHA concept, as it is today, is based on the coupling of an upgraded commercial proton accelerator with a spallation target surrounded by a subcritical neutron-multiplying medium. Its design is determined by the versatility m applications that should be made possible. Further technical and/or strategic developments of the project might change the concept. A cyclotron, based on positive ion acceleration technology brings the protons up to an energy level of 350 MeV. The nominal current is 5 mA of protons. The spallation target system consists in a circuit with, at the upper part, a free

  17. Photonic crystal laser-driven accelerator structures

    Cowan, Benjamin

    2005-01-01

    We discuss simulated photonic crystal structure designs, including two- and three-dimensional planar structures and fibers. The discussion of 2D structures demonstrates guiding of a speed-of-light accelerating mode by a defect in a photonic crystal lattice and reveals design considerations and trade-offs. With a three-dimensional lattice, we introduce a candidate geometry and discuss beam dynamics, coupling, and manufacturing techniques for that structure. In addition we discuss W-band scale tests of photonic crystal structures. The computational methods are also discussed.

  18. Compact Couplers for Photonic Crystal Laser-Driven Accelerator Structures

    Photonic crystal waveguides are promising candidates for laser-driven accelerator structures because of their ability to confine a speed-of-light mode in an all-dielectric structure. Because of the difference between the group velocity of the waveguide mode and the particle bunch velocity, fields must be coupled into the accelerating waveguide at frequent intervals. Therefore efficient, compact couplers are critical to overall accelerator efficiency. We present designs and simulations of high-efficiency coupling to the accelerating mode in a three-dimensional photonic crystal waveguide from a waveguide adjoining it at 90o. We discuss details of the computation and the resulting transmission. We include some background on the accelerator structure and photonic crystal-based optical acceleration in general.

  19. LAVENDER: A steady-state core analysis code for design studies of accelerator driven subcritical reactors

    Zhou, Shengcheng; Wu, Hongchun; Cao, Liangzhi; Zheng, Youqi, E-mail: yqzheng@mail.xjtu.edu.cn; Huang, Kai; He, Mingtao; Li, Xunzhao

    2014-10-15

    Highlights: • A new code system for design studies of accelerator driven subcritical reactors (ADSRs) is developed. • S{sub N} transport solver in triangular-z meshes, fine deletion analysis and multi-channel thermal-hydraulics analysis are coupled in the code. • Numerical results indicate that the code is reliable and efficient for design studies of ADSRs. - Abstract: Accelerator driven subcritical reactors (ADSRs) have been proposed and widely investigated for the transmutation of transuranics (TRUs). ADSRs have several special characteristics, such as the subcritical core driven by spallation neutrons, anisotropic neutron flux distribution and complex geometry etc. These bring up requirements for development or extension of analysis codes to perform design studies. A code system named LAVENDER has been developed in this paper. It couples the modules for spallation target simulation and subcritical core analysis. The neutron transport-depletion calculation scheme is used based on the homogenized cross section from assembly calculations. A three-dimensional S{sub N} nodal transport code based on triangular-z meshes is employed and a multi-channel thermal-hydraulics analysis model is integrated. In the depletion calculation, the evolution of isotopic composition in the core is evaluated using the transmutation trajectory analysis algorithm (TTA) and fine depletion chains. The new code is verified by several benchmarks and code-to-code comparisons. Numerical results indicate that LAVENDER is reliable and efficient to be applied for the steady-state analysis and reactor core design of ADSRs.

  20. Simulation study of an accelerator driven as a transmutation and energy generation system

    In twenty first century world is facing two issues of future concern, generation of clean energy and the protection of the environment. Oil price is soaring to a level of jeopardizing world economy and on the other hand burning fossil fuel is reaching to a point of endangering life of all creatures. The sole solution to compete the energy shortage is exploiting nuclear energy and other clean energy sources. The main concern of nuclear energy is long term radioactive waste. In principle, any nuclear reactor is able to burn and transmute minor actinides, but reactors with fast neutron spectrum must be preferred, as they allow a positive neutron gain throughout the burning process. A core dedicated to the transmutation of the minor actinides should be designed in order to minimize its self-production of actinides. A possible solution to these problems is represented by a subcritical system driven by an accelerator, which is able to safely bum and/or transmute actinides and long lived fission products, as it does not rely on delayed neutrons for control or power change and the reactivity feedbacks have only limited importance during transient response. In this study, an accelerator driven system based on Japanese design was simulated using MCNPX code to calculate neutron spectrum flux level, core sub-criticality and peaking factor

  1. Linear accelerator driven (LADR) and regenerative reactors (LARR) for nuclear non-proliferation

    Linear accelerator breeders (LAB) could be used to produce fissile fuel in two modes, either with fuel reprocessing or without fuel reprocessing. With fuel reprocessing, the fissile material would be separated from the target and refabricated into a fuel element for use in a burner power reactor. Without reprocessing, the fissile material would be produced in-situ, either in a fresh fuel element or in a depleted or burned element after use in a power reactor. In the latter mode the fissile material would be increased in concentration for reuse in a power reactor. This system is called a Linear Accelerator Regenerative Reactor (LARR). The LAB can also be conceived of operating in a power production mode in which the spallation neutrons would be used to drive a subcritical assembly to produce power. This is called a Linear Accelerator Driven Reactor (LADR). A discussion is given of the principles and some of the technical problems of both types of accelerator breeders

  2. Accelerator-based neutron source for the neutron-capture and fast neutron therapy at hospital

    Bayanov, B. F.; Belov, V. P.; Bender, E. D.; Bokhovko, M. V.; Dimov, G. I.; Kononov, V. N.; Kononov, O. E.; Kuksanov, N. K.; Palchikov, V. E.; Pivovarov, V. A.; Salimov, R. A.; Silvestrov, G. I.; Skrinsky, A. N.; Soloviov, N. A.; Taskaev, S. Yu.

    The proton accelerator complex for neutron production in lithium target discussed, which can operate in two modes. The first provides a neutron beam kinematically collimated with good forward direction in 25° and average energy of 30 keV, directly applicable for neutron-capture therapy with high efficiency of proton beam use. The proton energy in this mode is 1.883-1.890 MeV that is near the threshold of the 7Li( p, n) 7Be reaction. In the second mode, at proton energy of 2.5 MeV, the complex-produced neutron beam with maximum energy board of 790 keV which can be used directly for fast neutron therapy and for neutron-capture therapy after moderation. The project of such a neutron source is based on the 2.5 MeV original electrostatic accelerator tandem with vacuum insulation developed at BINP which is supplied with a high-voltage rectifier. The rectifier is produced in BINP as a part of ELV-type industrial accelerator. Design features of the tandem determining its high reliability in operation with a high-current (up to 40 mA) H - ion beam are discussed. They are: the absence of ceramic accelerator columns around the beam passage region, good conditions for pumping out of charge-exchange gaseous target region, strong focusing optics and high acceleration rate minimizing the space charge effects. The possibility of stabilization of protons energy with an accuracy level of 0.1% necessary for operation in the near threshold region is considered. The design description of H - continuous ion source with a current of 40 mA is also performed. To operate with a 100 kW proton beam it is proposed to use liquid-lithium targets. A thin lithium layer on the surface of a tungsten disk cooled intensively by a liquid metal heat carrier is proposed for use in case of the vertical beam, and a flat liquid lithium jet flowing through the narrow nozzle - for the horizontal beam.

  3. BINP pilot accelerator-based neutron source for neutron capture therapy

    Neutron source based on accelerator has been proposed for neutron capture therapy at hospital. Innovative approach is based upon tandem accelerator with vacuum insulation and near threshold 7Li(p,n)7Be neutron generation. Pilot innovative accelerator based neutron source is under going to start operating now at BINP, Novosibirsk. Negative ion source with Penning geometry of electrodes has been manufactured and dc H- ion beam has been obtained. Study of beam transport was carried out using prototype of tandem accelerator. Tandem accelerator and ion optical channels have been manufactured and assembled. Neutron producing target has been manufactured, thermal regimes of target were studied, and lithium evaporation on target substrate was realized. In the report, the pilot facility design is given and design features of facility components are discussed. Current status of project realization, results of experiments and simulations are presented. (author)

  4. Weapon plutonium in accelerator driven power system

    The purpose and problems of the research - creation of a safe and reliable ADS for processing of about 25 tons of weapons plutonium in 30 years on the basis of a proton-accelerator with energies 0.8-1.2 GeV and a current of 10-30 mA; liquid Pb/Bi eutectic targets; one-directionally coupled fast/thermal blanket with plutonium fuel. The approach to weapons-Pu utilization is based on the understanding of the unconditional priority of safety features of ADS over economic considerations and, accordingly, on the priority of subcritical systems over critical. The description of a variant of ADS from the point of view of possibilities of its realization in an acceptable period of time on the base of approbated technologies is presented here. 7 refs., 4 figs., 1 tab

  5. Study of deuteron-induced reaction for nuclear design of accelerator neutron sources for medical application

    Nakayma, S.; Araki, S.; Kawagoe, T.; Kin, T.; Watanabe, Y.

    2014-07-01

    In recent years, accelerator-driven neutron sources using deuteron-induced (d,xn) reactions on light nuclei {sup 7}Li, {sup 9}be, {sup 1}2C, etc.) have attracted attention in various fields. Figure 1 shows experimental thick target neutron yields from (p,xn) and (d,nn) reactions on {sup 9}Be. This figure shows some advantages of a (d,xn) neutron source over a (p,xn) neutron source. First, the amount of generated neutrons is large. Second, the neutron spectrum has a broad energy peak around half the deuteron incident energy. This means that the most probable neutron energy can be changed by adjusting incident deuteron energy. In addition, the (d,xn) reactions has strongly forward-peaked angular distribution, which is an additional advantage from the point of view of shielding. From these favorable features, accelerator neutron sources using deuteron-induced reaction have been proposed not only for irradiation testing of fusion reactor materials but also for medical purposes. (Author)

  6. Measurement of subcriticality using delayed neutron source combined with pulsed neutron accelerator

    A new experimental method for subcriticality measurement was developed by using delayed neutron source which is produced by external pulsed neutron source to increase accuracy of measured results by overcoming the space dependency problem which means difference of measured results in different detector position and often appeared in almost all other subcriticality measurement techniques. Experiments were performed at Kyoto University Critical Assembly (KUCA) combined with a DT accelerator to produce pulsed neutron in outside of the core repeatedly. In this method, neutron detection counts in the prompt neutron time region which are appeared just after injection of pulsed neutron are omitted, whereas neutron counts in the delayed neutron time region which are appeared after disappearance of exponential decay of the prompt neutron are adopted in analysis based on neutron source multiplication method or neutron noise analysis method; the variance to mean ratio method. In the delayed neutron time region, neutron sources to initiate fission chain reactions in subcritical state are delayed neutrons from delayed neutron precursors which are mainly produced by fission chain reactions in the prompt neutron time region, and delayed neutron precursors exist only in the fuel region, which makes possible to decrease the space dependency problem. The obtained results were compared with conventional pulsed neutron method, and it was found that the space dependency problem in subcriticality measurement can be fairly decreased by using the present new method compared with conventional one. (author)

  7. Neutron Scattering Simulations at the University of Kentucky Accelerator Laboratory

    Nguyen, Thienan; Jackson, Daniel; Hicks, S. F.; Rice, Ben; Vanhoy, J. R.

    2015-10-01

    The Monte-Carlo N-Particle Transport code (MCNP) has many applications ranging from radiography to reactor design. It has particle interaction capabilities, making it useful for simulating neutron collisions on surfaces of varying compositions. The neutron flux within the accelerator complex at the University of Kentucky was simulated using MCNP. With it, the complex's capabilities to contain and thermalize 7 MeV neutrons produced via 2H(d,n)3He source reaction to an acceptable level inside the neutron hall and adjoining rooms were analyzed. This will aid in confirming the safety of researchers who are working in the adjacent control room. Additionally, the neutron transport simulation was used to analyze the impact of the collimator copper shielding on various detectors located around the neutron scattering hall. The purpose of this was to attempt to explain any background neutrons that are observed at these detectors. The simulation shows that the complex performs very well with regards to neutron containment and thermalization. Also, the tracking information for the paths taken by the neutrons show that most of the neutrons' lives are spent inside the neutron hall. Finally, the neutron counts were analyzed at the positions of the neutron monitor detectors located at 90 and 45 degrees relative to the incident beam direction. This project was supported in part by the DOE NEUP Grant NU-12-KY-UK-0201-05 and the Donald A. Cowan Physics Institute at the University of Dallas.

  8. System and safety studies of accelerator driven transmutation systems. Annual report 1998

    Wallenius, J.; Gudowski, W.; Carlsson, Johan; Eriksson, Marcus; Tucek, K. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Nuclear and Reactor Physics

    1998-12-01

    This annual report describes the accelerator-driven transmutation project conducted at the Department of Nuclear and Reactor Physics at the Royal Institute of Technology. The main results are: development of the simulation tools for accelerator-driven transmutation calculations including an integrated Monte-Carlo burnup module and improvements of neutron energy fission yield simulations, processing of the evacuated nuclear data files including preparation of the temperature dependent neutron cross-sections, development of nuclear data for a medium energy range for some isotopes, development of the models and codes for radiation damage simulations, system studies for the spent fuel transmuter, based on heavy metal coolant and advanced nuclear fuel, contribution to the spallation target design being manufactured in IPPE, Obninsk, and accelerator reliability studies. Moreover a lot of efforts were put to further develop existing international collaboration with the most active research groups in the world together with educational activities in Sweden including a number of meetings and workshops and a graduate course in transmutation. This project has been conducted in close collaboration with the EU-project `Impact of the accelerator based technologies on nuclear fission safety` - IABAT and in bilateral cooperation with different foreign research groups 31 refs, 23 figs

  9. System and safety studies of accelerator driven transmutation systems. Annual report 1998

    This annual report describes the accelerator-driven transmutation project conducted at the Department of Nuclear and Reactor Physics at the Royal Institute of Technology. The main results are: development of the simulation tools for accelerator-driven transmutation calculations including an integrated Monte-Carlo burnup module and improvements of neutron energy fission yield simulations, processing of the evacuated nuclear data files including preparation of the temperature dependent neutron cross-sections, development of nuclear data for a medium energy range for some isotopes, development of the models and codes for radiation damage simulations, system studies for the spent fuel transmuter, based on heavy metal coolant and advanced nuclear fuel, contribution to the spallation target design being manufactured in IPPE, Obninsk, and accelerator reliability studies. Moreover a lot of efforts were put to further develop existing international collaboration with the most active research groups in the world together with educational activities in Sweden including a number of meetings and workshops and a graduate course in transmutation. This project has been conducted in close collaboration with the EU-project 'Impact of the accelerator based technologies on nuclear fission safety' - IABAT and in bilateral cooperation with different foreign research groups

  10. Neutron generation by laser-driven photonuclear reaction

    It has been demonstrated that laser-driven high-energy x-ray source could be an approvable candidate for a neutron source with flat energy spectrum. A gold disk target was irradiated by a kJ pulse from the high power laser system (LFEX) at Osaka University to show the neutron generation of 8 x 108. Generation of high energy x-ray component with higher temperature necessary for neutron generation via photonuclear reaction is attributed to interaction of laser with the long scale preformed plasma. (author)

  11. Neutron dosimetry with TL albedo dosemeters at high energy accelerators

    The GSF-Personal Monitoring Service uses the TLD albedo dosemeter as standard neutron personal dosemeter. Due to its low sensitivity for fast neutrons however, it is generally not recommended for workplaces at high-energy accelerators. Test measurements with the albedo dosemeter were performed at the accelerator laboratories of GSI in Darmstadt and DESY in Hamburg to reconsider this hypothesis. It revealed that the albedo dosemeter can also be used as personal dosemeter at these workplaces, because at all measurement locations a significant part of neutrons with lower energies could be found, which were produced by scattering at walls or the ground. (authors)

  12. Real time spectrometer for thermal neutrons from radiotherapic accelerators

    Mozzanica, A. [Universita degli Studi di Brescia e INFN sezione di Pavia (Italy)], E-mail: mozzanica@bs.infn.it; Bartesaghi, G.; Bolognini, D.; Conti, V.; Mascagna, V.; Prest, M.; Scazzi, S. [Universita degli Studi dell' Insubria e INFN sezione di Milano/Milano Bicocca (Italy); Cappelletti, P.; Frigerio, M.; Gelosa, S.; Monti, A.; Ostinelli, A. [Fisica Sanitaria, Ospedale S. Anna di Como (Italy); Bevilacqua, R.; Giannini, G.; Totaro, P.; Vallazza, E. [INFN, sezione di Trieste e Universita degli Studi di Trieste (Italy)

    2007-10-15

    Radiotherapy accelerators can produce high energy photon beams for deep tumour treatments. Photons with energies greater than 8 MeV produce neutrons via photoproduction. The PHONES (PHOto NEutron Source) project is developing a neutron moderator to use the photoproduced neutrons for BNCT (Boron Neutron Capture Therapy) in hospital environments. In this framework we are developing a real time spectrometer for thermal neutrons exploiting the bunch structure of the beam. Since the beam is produced by a linear accelerator, in fact, particles are sent to the patient in bunches with a rate of 150-300 Hz depending on the beam type and energy. The neutron spectrum is usually measured with integrating detectors such as bubble dosimeters or TLDs, which integrate over a time interval and an energy one. We are developing a scintillator detector to measure the neutron spectrum in real time in the interval between bunches, that is in the thermal region. The signals from the scintillator are discriminated and sampled by a dedicated clock in a Cyclone II FPGA by Altera, thus obtaining the neutron time of flight spectrum. The exploited physical process in ordinary plastic scintillators is neutron capture by H with a subsequent {gamma} emission. The measured TOF spectrum has been compared with a BF{sub 3} counter one. A dedicated simulation with MCNP is being developed to extract the energy spectrum from the TOF one. The paper will present the results of the prototype measurements and the status of the simulation.

  13. Accelerator-driven system design concept for disposing of spent nuclear fuels

    At present, the US SNF (Spent Nuclear Fuel) inventory is growing by about 2,000 metric tonnes (MT) per year from the current operating nuclear power plants to reach about 70,000 MT by 2015. This SNF inventory contains about 1% transuranics (700 MT), which has about 115 MT of minor actinides. Accelerator-driven systems utilising proton accelerators with neutron spallation targets and subcritical blankets can be utilised for transmuting these transuranics, simultaneously generating carbon free energy, and significantly reducing the capacity of the required geological repository storage facility for the spent nuclear fuels. A fraction of the SNF plutonium can be used as a MOX fuel in the current/future thermal power reactors and as a starting fuel for future fast power reactors. The uranium of the spent nuclear fuel can be recycled for use in future nuclear power plants. This paper shows that only four to five accelerator-driven systems operating for less than 33 full power years can dispose of the US SNF inventory expected by 2015. In addition, a significant fraction of the long-lived fission products will be transmuted at the same time. Each system consists of a proton accelerator with a neutron spallation target and a subcritical assembly. The accelerator beam parameters are 1 GeV protons and 25 MW beam power, which produce 3 GWt in the subcritical assembly. A liquid metal (lead or lead-bismuth eutectic) spallation target is selected because of design advantages. This target is located at the centre of the subcritical assembly to maximise the utilisation of spallation neutrons. Because of the high power density in the target material, the target has its own coolant loop, which is independent of the subcritical assembly coolant loop. Mobile fuel forms with transuranic materials without uranium are considered in this work with liquid lead or lead-bismuth eutectic as fuel carrier

  14. Application of a removable accelerator to fast neutron imaging

    Working principle and structure and debugging process of a mobile accelerator are introduced. The mobile accelerator, compact and light-weighted, can produce beam currents with high stability and small spot, and it is used in experiment of fast neutron imaging in our academy for the first time. In application process, some parameters including the beam current stability parameter are measured. Successive neutron yield is measured using concomitance particle means. Elementary images are acquired to fit the accelerator and the digital imaging system together. (authors)

  15. Production of neutrons in particle accelerators: a PNRI safety concern

    In the safety assessment made for the first cyclotron facility in the Philippines, that is the cyclotron in the P.E.T. (Positron Emission Tomography) center of the St. Luke's Medical Center, the concern on the production of neutrons associated with the operation of particle accelerators has been identified. This takes into consideration the principles in the operation of particle accelerators and the associated production of neutrons resulting from their operation, the hazards and risks in their operation. The Bureau of Health Devices and Technology (BHDT) of the Department of Health in the Philippines regulates and controls the presently existing six (6) linear accelerators distributed in different hospitals in the country, being classified as x-ray producing devices. From the results of this study, it is evident that the production of neutrons from the operation of accelerators, produces neutrons and that activation due to neutrons can form radioactive materials. The PNRI (Philippine Nuclear Research Institute) being mandated by law to regulate and control any equipment or devices producing or utilizing radioactive materials should take the proper steps to subject all accelerator facilities and devices in the Philippines such as linear accelerators under its regulatory control in the same manner as it did with the first cyclotron in the country. (Author)

  16. Fusion-neutron-yield, activation measurements at the Z accelerator: Design, analysis, and sensitivity

    Hahn, K. D., E-mail: kdhahn@sandia.gov; Ruiz, C. L.; Fehl, D. L.; Chandler, G. A.; Knapp, P. F.; Smelser, R. M.; Torres, J. A. [Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123 (United States); Cooper, G. W.; Nelson, A. J. [Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Leeper, R. J. [Los Alamos National Laboratories, Plasma Physics Group, Los Alamos, New Mexico 87545 (United States)

    2014-04-15

    We present a general methodology to determine the diagnostic sensitivity that is directly applicable to neutron-activation diagnostics fielded on a wide variety of neutron-producing experiments, which include inertial-confinement fusion (ICF), dense plasma focus, and ion beam-driven concepts. This approach includes a combination of several effects: (1) non-isotropic neutron emission; (2) the 1/r{sup 2} decrease in neutron fluence in the activation material; (3) the spatially distributed neutron scattering, attenuation, and energy losses due to the fielding environment and activation material itself; and (4) temporally varying neutron emission. As an example, we describe the copper-activation diagnostic used to measure secondary deuterium-tritium fusion-neutron yields on ICF experiments conducted on the pulsed-power Z Accelerator at Sandia National Laboratories. Using this methodology along with results from absolute calibrations and Monte Carlo simulations, we find that for the diagnostic configuration on Z, the diagnostic sensitivity is 0.037% ± 17% counts/neutron per cm{sup 2} and is ∼ 40% less sensitive than it would be in an ideal geometry due to neutron attenuation, scattering, and energy-loss effects.

  17. Magnetically-driven crustquakes in neutron stars

    Lander, S K; Antonopoulou, D; Watts, A L

    2014-01-01

    Crustquake events may be connected with both rapid spin-up `glitches' within the regular slowdown of neutron stars, and high-energy magnetar flares. We argue that magnetic field decay builds up stresses in a neutron star's crust, as the elastic shear force resists the Lorentz force's desire to rearrange the global magnetic-field equilibrium. We derive a criterion for crust-breaking induced by a changing magnetic-field configuration, and use this to investigate strain patterns in a neutron star's crust for a variety of different magnetic-field models. Universally, we find that the crust is most liable to break if the magnetic field has a strong toroidal component, in which case the epicentre of the crustquake is around the equator. We calculate the energy released in a crustquake as a function of the fracture depth, finding that it is independent of field strength. Crust-breaking is, however, associated with a characteristic local field strength of $2.4\\times 10^{14}$ G for a breaking strain of $0.001$, or $2....

  18. Estimation of neutron backgrounds at neutron target room in JAERI 20 MV Tandem Accelerator Facility

    Two-dimensional discrete-ordinates codes have been used to calculate neutron backgrounds in the neutron target room and dose-equivalent rate outside of the JAERI 20 MV Tandem Accelerator building. The energy range of source neutrons used for the calculations was from 10 to 40 MeV. It is shown that the background neutrons at the position of the neutron detector in the target room are mainly composed of the floor-scattered neutrons, and with increase of the energy of source neutrons it becomes difficult to shield the neutron detector against the floor-scattered neutrons. It is also shown that the thickness of the concrete wall of the building is sufficient to reduce the dose-equivalent rate outside of the building. (author)

  19. Experimental subcritical facility driven by D-D/D-T neutron generator at BARC, India

    Highlights: •Experimental subcritical facility BRAHMMA coupled to D-D/D-T neutron generator. •Preliminary results of PNS experiments reported. •Feynman-alpha noise measurements explored with continuous source. -- Abstract: The paper presents design of an experimental subcritical assembly driven by D-D/D-T neutron and preliminary experimental measurements. The system has been developed for investigating the static and dynamic neutronic properties of accelerator driven sub-critical systems. This system is modular in design and it is first in the series of subcritical assemblies being designed. The subcritical core consists of natural uranium fuel with high density polyethylene as moderator and beryllium oxide as reflector. The fuel is embedded in high density polyethylene moderator matrix. Estimated keff of the system is ∼0.89. One of the unique features of subcritical core is the use of Beryllium oxide (BeO) as reflector and HDPE as moderator making the assembly a compact modular system. The subcritical core is coupled to Purnima Neutron Generator which works in D-D and D-T mode with both DC and pulsed operation. It has facility for online source strength monitoring using neutron tagging and programmable source modulation. Preliminary experiments have been carried out for spatial flux measurement and reactivity estimation using pulsed neutron source (PNS) techniques with D-D neutrons. Further experiments are being planned to measure the reactivity and other kinetic parameters using noise methods. This facility would also be used for carrying out studies on effect of source importance and measurement of source multiplication factor ks and external neutron source efficiency φ∗ in great details. Experiments with D-T neutrons are also underway

  20. Conceptual design of a commercial accelerator driven thorium reactor

    This paper describes the substantial work done in underpinning and developing the concept design for a commercial 600 MWe, accelerator driven, thorium fuelled, lead cooled, power producing, fast reactor. The Accelerator Driven Thorium Reactor (ADTR TM) has been derived from original work by Carlo Rubbia. Over the period 2007 to 2009 Aker Solutions commissioned this concept design work and, in close collaboration with Rubbia, developed the physics, engineering and business model. Much has been published about the Energy Amplifier concept and accelerator driven systems. This paper concentrates on the unique physics developed during the concept study of the ADTR TM power station and the progress made in engineering and design of the system. Particular attention is paid to where the concept design has moved significantly beyond published material. Description of challenges presented for the engineering and safety of a commercial system and how they will be addressed is included. This covers the defining system parameters, accelerator sizing, core and fuel design issues and, perhaps most importantly, reactivity control. The paper concludes that the work undertaken supports the technical viability of the ADTR TM power station. Several unique features of the reactor mean that it can be deployed in countries with aspirations to gain benefit from nuclear power and, at 600 MWe, it fits a size gap for less mature grid systems. It can provide a useful complement to Generation III, III+ and IV systems through its ability to consume actinides whilst at the same time providing useful power. (authors)

  1. Accelerator driven systems for transmutation and energy production: challenges and dangers

    Accelerator driven systems (ADS) are an old technological idea: relativistic proton accelerators deliver their beams onto massive heavy element targets, thus producing abundant neutron fluences. Placing this target into sub-critical nuclear fission assemblies is yielding substantial fission reactions, thus additional fission energy (Rubbia called such a system ''energy amplifier''). This technology has recently attracted considerable attention due to advances in the construction of powerful accelerators. It allows the safe and cheap production of nuclear energy simultaneously with the destruction (transmutation) of long lived radioactive waste, in particular plutonium and other minor actinides (neptunium and americium). The principles and the present-state-of-the-art are described, including first experiments to transmute plutonium this way. This technology needs, however, many more years of further ''research and development'' before large scale ADS's can be constructed. It may be even necessary to investigate the question, if all basic physics phenomena of this technology are already sufficiently well understood. (orig.)

  2. Compact RF-driven, pulsed ion sources for neutron tube applications

    Compact radio-frequency (RF) driven ion sources are being developed in the Lawrence Berkeley National Laboratory (LBNL) for sealed-accelerator-tube neutron generator applications. This portable generator is projected to produce a neutron flux in the range of 109 to 1010 D-T neutrons per second. A 2 MHz RF-driven ion source designed for a 5-cm-diameter neutron tube has been developed. Typical operating parameters include repetition rates up to 100 pps, with pulse widths between 10 and 80 μs and source operating pressure as low as 4 m Torr. By using a computer designed 100 keV accelerator column, peak extractable hydrogen current exceeding 1 A has been from a 3-mm-diameter aperture, together with H+ yields over 94% have been achieved. An RF impedance matching network has also been successfully miniaturized to ∼5 cm diameter and tested. For low duty factor operations, the ion source and matching circuit do not require any cooling. (author)

  3. The study of neutron burst shape of a neutron tube driven by dispenser cathode

    Grishnyaev, Evgeny; Polosatkin, Sergey

    2016-08-01

    A slim-shaped portable DD-neutron generator is developed at Budker institute of Nuclear Physics. The generator is a combination of Cockcroft-Walton voltage multiplier and a sealed gas-filled neutron tube driven by dispenser cathode. Neutron burst shape in pulsed mode of neutron tube operation is measured with stroboscopic time spectrometry, implemented on scintillation detector, and modeled with Comsol Script 1.3 and Comsol Multiphysics 3.5. Modeling appears to be in good agreement with experimental results. Measured pulse rise and fall times are 110 ns and 100 ns respectively.

  4. Acceleration and deceleration of neutrons: From the phase modulation of a neutron wave to a neutron turbine with refracting prisms

    The possibility of the acceleration and deceleration of neutrons undergoing diffraction at a moving grating is discussed. It is shown that, in contrast to phase π gratings used at the present time, which form a discrete spectrum featuring a large number of lines, a grating that has a special profile may shift, under certain conditions, the entire spectrum of diffracted neutrons. A blazing grating of this type may be used in efficiently accelerating and decelerating neutrons. As the scale of the structure becomes larger, a description based on the idea of neutron-wave refraction at its elements becomes valid, a system of moving prims forming a “neutron turbine,” which is also able to accelerate or decelerate neutrons, being a classical limit of this enlargement.

  5. IPNS accelerator system and neutron chopper synchronization

    Several of the neutron scattering instruments at the Intense Pulsed Neutron Source (IPNS) at Argonne use neutron choppers for monochromatization of the neutron beam. Since the neutron burst is produced by a proton beam extracted from the Rapid Cycling Synchrotron (RCS), precise synchronization must be maintained between the RCS and the chopper aperture to minimize the degradation of energy resolution. The first attempts at synchronization were made in 1978 on the ZING-P' facility with a single chopper. Synchronization was further complicated after IPNS began operating in 1981 when a total of three chopper experiments came on-line. The system in use during that period of time was able to maintain synchronization with typical data collection efficiencies ranging from 20 to 70%. A synchronization system improvement, installed in late 1982, increased the data collection efficiencies of all the IPNS chopper systems to 99+%. The development of the RCS and neutron chopper synchronization system is described together with a detailed description of the present system

  6. Improved modelling of the neutron spectrum for the ASP accelerator

    Highlights: • An improved estimate of the ASP neutron spectrum is calculated using unfolding methods. • Zr and Nb activation foil measurements used to calculate mean neutron energy. • Simulation of the neutron production for a range of deuteron beam conditions. • Combination of experiment and simulation used as inputs to unfolding code MAXED. • The unfolded spectrum shows a small increase in the number of 10–14 MeV neutrons. -- Abstract: As part of CCFE's nuclear data and technology programmes a series of material irradiations have been performed at the ASP accelerator to determine integral reaction cross-sections for fusion relevant materials. The integral reaction cross section can be used as part of the validation of the cross section data. The ASP machine accelerates deuterons onto a tritiated target to produce approximately 14 MeV neutrons via the D–T fusion reaction. These neutrons interact with the material creating radioactive isotopes. The gamma emissions from the activated products are then measured using a high resolution gamma spectroscopy system. An important part of evaluating the results of these and future experiments lies in an accurate determination of the neutron energy spectrum. Initially a neutron spectrum determined by MCNP modelling was used based on a source term calculated using relativistic kinematics. The work reported here improves the understanding of the neutron spectrum using a combination of enhanced modelling and experimental data as input information to be used in spectrum unfolding. Recent advances in simulation techniques allow us to use deuteron cross sections for low energy deuterons and hence model the production of neutrons by the deuterons explicitly. This means that it is possible to model the effect of changing various deuteron beam parameters such as radius, energy and position on the target to understand what influence these have on the spectrum seen at the material of interest. The spectrum unfolding

  7. Research of accelerator-based neutron source for boron neutron capture therapy

    Background: 7Li (p, n) reaction of high neutron yield and low threshold energy has become one of the most important neutron generating reactions for Accelerator-based Boron Neutron Capture Therapy (BNCT). Purpose Focuses on neutron yield and spectrum characteristics of this kind of neutron generating reaction which serves as an accelerator-based neutron source and moderates the high energy neutron beams to meet BNCT requirements. Methods: The yield and energy spectrum of neutrons generated by accelerator-based 7Li(p, n) reaction with incident proton energy from 1.9 MeV to 3.0 MeV are researched using the Monte Carlo code-MCNPX2.5.0. And the energy and angular distribution of differential neutron yield by 2.5-MeV incident proton are also given in this part. In the following part, the character of epithermal neutron beam generated by 2.5-MeV incident protons is moderated by a new-designed moderator. Results: Energy spectra of neutrons generated by accelerator-based 7Li(p, n) reaction with incident proton energy from 1.9 MeV to 3.0 MeV are got through the simulation and calculation. The best moderator thickness is got through comparison. Conclusions: Neutron beam produced by accelerator-based 7Li(p, n) reaction, with the bombarding beam of 10 mA and the energy of 2.5 MeV, can meet the requirement of BNCT well after being moderated. (authors)

  8. Ashing vs. electric generation in accelerator driven system

    Accelerator Driven Systems have been conceived as an alternative for the processing of the radioactive wastes contained in spent fuel elements from nuclear power plants. These systems are formed by the coupling of a nuclear reactor - preferably a subcritical reactor - with a particle accelerator providing particles with energy in the order of the GeV. The long-lived fission products and actinides of the spent fuels are transformed by nuclear reactions in stable isotopes or in short-lived radioisotopes. The basic parameters for the electric energy production of the different systems are analysed. (author)

  9. Nonlinear Laser Driven Donut Wakefields for Positron and Electron Acceleration

    Vieira, J.; Mendonça, J. T.

    2014-05-01

    We show analytically and through three-dimensional particle-in-cell simulations that nonlinear wakefields driven by Laguerre-Gaussian laser pulses can lead to hollow electron self-injection and positron acceleration. We find that higher order lasers can drive donut shaped blowout wakefields with strong positron accelerating gradients comparable to those of a spherical bubble. Corresponding positron focusing forces can be more than an order of magnitude stronger than electron focusing forces in a spherical bubble. Required laser intensities and energies to reach the nonlinear donut shaped blowout are within state-of-the-art experimental conditions.

  10. MYRRHA project: a Multipurpose Accelerator Driven System (ADS) for R and D

    The objective of the MYRRHA project is to develop a multipurpose neutron source for research and development applications on the basis of an Accelerator Driven System (ADS). Current activities in this area focus on (1) the continuation and the extension towards ADS of the ongoing programmes at SCK-CEN in the field of reactor materials, fuel and reactor physics research; (2) the enhancement and the triggering of new R and D activities such as nuclear waste transmutation, ADS technology, liquid metal embrittlement; (3) the initiation of medical applications, for example proton therapy and PET production, or proton Based irradiation programmes. Main achievements in these topical areas in 2000 are summarised

  11. Neutronic limits in various target mediums driven by a proton beam of 1 GeV energy

    The concept of accelerator-driven system (ADSs) combines a particle accelerator with a subcritical core. The basic process in an AD is nuclear transmutation, and in general, an ADS consists of three parts: (1) accelerator, (2) spallation-neutron target (SNT) and (3) sub-critical core which surrounds the SNT. This study presents the neutronic characteristics of integral data in an infinite target medium driven by an isotropic point source of 1 GeV incident proton. Lead bismuth eutectic, mercury, tungsten, uranium, thorium, chromium, cupper and beryllium are considered as the target material because of their favorable spallation-neutron production characteristics. In order to be able to simulate the infinite target medium by eliminating the spatial dependence, a spherical target is considered, and its radius is increased gradually up to adequate radius ensuring the infinite target medium. In this way, the radius value ensuring the maximum neutron leakage out of the target would be determined. Numerical calculations were performed with the high-energy Monte Carlo code MCNPX in coupled neutron and proton mode using the LA150 library. The results bring out that a significant ratio (92-99%) of the leaking neutrons is below 20 MeV in the lead-bismuth eutectic, mercury, tungsten and uranium target materials. The maximum neutron leakage quantities for chromium, cupper and beryllium are an extremely low for a SNT

  12. Sustained nuclear energy without weapons or reprocessing using accelerator-driven systems

    Accelerator-driven thermal-spectrum molten-salt nuclear technology can greatly simplify nuclear energy technology by eliminating reprocessing and greatly enhancing once-through burn-up. In effect the accelerator may be employed as a substitute for frequent reprocessing and recycle. The accelerator makes possible reduction in plutonium and minor actinides from current LWRs by a factor of more than ten without reprocessing while converting the plutonium remnant to a non-weapons-useful isotopic composition. The accelerator also enhances the once-through energy production from fertile material by a factor of ten without reprocessing compared to once-through LWR technology. This technology would eliminate the need to deploy plutonium production indefinitely, and reprocessing and recycle for at least several hundred years. The energy production technology proposed here operates primarily on the Th-U cycle with a minor contribution from the U-Pu cycle to eliminate the weapons-usefulness of 233U. There are two key innovations in addition to the accelerator. One is the use of liquid fuel flowing once through a pool of material undergoing fission thereby allowing high burn-up concurrently with continuous removal of fission product without reprocessing. The second is the unanticipated low capture cross section of fission product nuclides which substantially enhances the neutron economy in this type of system. The supplement of neutrons from the accelerator, the reduced fission product neutron capture, and the continuously flowing fuel are the enablers for the performance described here. This technology allows an essentially complete decoupling of nuclear energy from nuclear weapons (orig.)

  13. Thermal-hydraulics of lead bismuth for accelerator driven systems

    Full text of publication follows: Lead bismuth has been selected as one of the most suitable coolants to be used in accelerator driven systems (ADS) for transmutation of minor actinides. It serves both, as a target material of the spallation source to balance the neutron economy, and as a coolant with high thermal inertia to provide a safe and reliable heat transfer to the secondary power cycle. With the aim to develop the required technologies to enable the later design of such ADS systems, the Karlsruhe Lead bismuth LAboratory KALLA, consisting of three test loops, has been built and set into operation at the Forschungszentrum Karlsruhe since 2000, keeping more than 45 t of PbBi in operation at temperatures up to 550 deg. C. The test program includes oxygen control systems, heat flux simulation tools, electro-magnetic and mechanical pump technologies, heat transfer and flow measurements, reliability and corrosion tests. In a first test campaign, a technology loop called THESYS was built to develop measurement technologies for the acquisition of scalar quantities, like pressures, temperatures, concentrations, and flow rates, as well as velocity fields, which are required for both operational and scientific purposes. THESYS also allowed to perform generic turbulent heat transfer experiments necessary to provide liquid metal adapted turbulent heat transfer models for ADS design analyses. The second loop, the thermalhydraulic loop THEADES with an installed power of 2.5 MW, has been built to conduct prototypical component experiments for beam windows (e.g. MEGAPIE or MYHRRA) or fuel rod configurations. First test results will be reported. The experimental team is supported by a numerical team who studied the thermal hydraulics of the tested components in order to enable a later transfer of the results to industrial systems. Three different types of codes are being improved: lumped parameter codes (e.g. ATHLET) to perform system analyses for lead bismuth in loops

  14. Laser-driven particle acceleration towards radiobiology and medicine

    2016-01-01

    This book deals with the new method of laser-driven acceleration for application to radiation biophysics and medicine. It provides multidisciplinary contributions from world leading scientist in order to assess the state of the art of innovative tools for radiation biology research and medical applications of ionizing radiation. The book contains insightful contributions on highly topical aspects of spatio-temporal radiation biophysics, evolving over several orders of magnitude, typically from femtosecond and sub-micrometer scales. Particular attention is devoted to the emerging technology of laser-driven particle accelerators and their applicatio to spatio-temporal radiation biology and medical physics, customization of non-conventional and selective radiotherapy and optimized radioprotection protocols.

  15. Accelerator based neutron source for the neutron capture therapy at hospital

    Accelerator source of epithermal neutrons for the hospital-based boron neutron capture therapy is proposed and discussed. Kinematically collimated neutrons are produced via near-threshold 7Li(p, n)7Be reaction at proton energies of 1.883 - 1.9 MeV. Steady-state accelerator current of 40 mA allows to provide therapeutically useful beams with treatment times of tens of minutes. The basic components of the facility are a hydrogen negative ion source, an electrostatic tandem accelerator with vacuum insulation, a sectioned rectifier, and a thin lithium neutron generating target on the surface of tungsten disk cooled by liquid metal heat carrier. Design features of facility components are discussed. The possibility of stabilization of proton energy is considered. At proton energy of 2.5 MeV the neutron beam production for NCT usage after moderation is also considered. (author)

  16. Neutron detector development and measurements around particle accelerators

    Various neutron detectors for spectrometry, environmental dosimetry and personal dosimetry have been developed by our group. For high energy neutron spectrometry, spallation detectors of C and Bi, large plastic and NE-213 scintillators, self TOF detector were used for neutron production and shielding experiments at several high energy accelerator facilities, ISIS of Rutherford Appleton Laboratory, UK, Two-mile Linac of Stanford Linear Accelerator Center, U.S.A., HIMAC of National Institute of Radiological Sciences, Japan, and RCNP of Osaka University, Japan. The response functions of these detectors were obtained by measurements and calculations. Thick target neutron yields produced from high-energy particles from protons to Xe ions have been summarized, together with shielding benchmark experiments through concrete and iron at these facilities. Neutron measurements over wide energy range including cosmic neutron field were done with Phoswich detector and Bonner sphere spectrometer. For environmental neutron dosimetry, two types of dose equivalent dosimeters, so-called rem counters, high-sensitive type and light-weight type, have been developed and for personal dosimetry, silicon semiconductor dosimeter has been developed for use in nuclear facilities. These dosimeters have good quality to give ambient and personal dose equivalents for neutrons in the mixed radiation fields. The outline of these works will be reviewed in this invited talk. (author)

  17. Novel neutron sources at the Radiological Research Accelerator Facility

    Xu, Y.; Garty, G.; Marino, S. A.; Massey, T. N.; Randers-Pehrson, G.; Johnson, G. W.; Brenner, D. J.

    2012-03-01

    Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a proton microbeam, impinging on a thin lithium target near the threshold of the 7Li(p,n)7Be reaction. This novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components.

  18. Transmutation of neptunium, americium, technetium, and iodine in fast spectrum cores driven by accelerated protons

    A neutronic analysis is presented of three incinerator subcritical lattices, driven by accelerated protons and designed to transmute the minor actinides, the 99Tc and the 129I, of light water reactor (LWR) waste. A calculational methodology must first be established to enable a neutronic burnup analysis of fission cores driven by high-energy protons. The methodology is based on the following codes: HERMES, the Forschungszentrum Juelich adaptation of HETC, for high-energy interactions; MCNP3, for neutron interactions below 20 MeV of neutron energy; and KORIGEN, the Forschungszentrum Karlsruhe adaptation of ORIGEN, for burnup analysis. A result of applying the methodology is that the minor actinides, the 99Tc, and the 129I, of LWR waste may be transmuted in subcritical cores, driven by the spallation neutrons emanating from the bombardment of the cores with 1600-MeV protons. Three cores types are required. Core type 1 is fueled by the minor actinides and is a modification of the Brookhaven National Laboratory PHOENIX. With a proton current of 20 mA, the core incinerates the minor actinide waste of 14 LWRs. Core type 2 contains the 99Tc, 129I, and plutonium waste of 19 LWRs. With a proton beam of 130 mA, the core incinerates the technetium and 60% of the iodine. With a faction of the plutonium coming out of this core, the remaining 40% of 129I is incinerated in core type 3. All three cores run to 100,000 MWd/tonne or slightly higher; on the average, no core is a net consumer of grid electricity; all are cooled by sodium but remain subcritical with the loss of coolant

  19. Advanced Approaches to High Intensity Laser-Driven Ion Acceleration

    Henig, Andreas

    2010-01-01

    Since the pioneering work that was carried out 10 years ago, the generation of highly energetic ion beams from laser-plasma interactions has been investigated in much detail in the regime of target normal sheath acceleration (TNSA). Creation of ion beams with small longitudinal and transverse emittance and energies extending up to tens of MeV fueled visions of compact, laser-driven ion sources for applications such as ion beam therapy of tumors or fast ignition inertial confinement fusion. Ho...

  20. Reactivity Monitoring of Accelerator-Driven Nuclear Reactor Systems

    Uyttenhove, W.

    2016-01-01

    This thesis provides a methodology and set-up of a reactivity monitoring tool for Accelerator-Driven Systems (ADS). The reactivity monitoring tool should guarantee the operation of an ADS at a safe margin from criticality. Robustness is assured in different aspects of the monitoring tool: the choice of the measurement techniques, the evaluation methods to derive the reactivity from experimental data, and the detector type and positioning. In the first chapter of the work, the experience from ...

  1. A study of neutron output from a medical linear accelerator

    In recent years, medical linear accelerators of higher energies (E>10 MeV) are becoming of common use in Brazil and the National Nuclear Energy Commission (CNEN) is facing the problem of licensing these Radiative Facilities. The question of how to shield these rooms, considering the neutron output from these machines, is not trivial. Many empirical models suggest how to calculate the neutron dose equivalent due to these particles, which are mainly produced trough (g,n) reactions in the accelerator head. In this article we present some measurements of neutrons produced by a 18 MeV Varian CLINAC 2100C linear accelerator at the Albert Einstein Hospital, in Sao Paulo, Brazil. The results are compared with theoretical calculations based on empirical models as well as on the equations presented in NCRP 79. (author)

  2. Neutronic fields produced by a lineal accelerator for radiotherapy

    Measurements and Monte Carlo calculations has been utilized to determine the dosimetric features as well as the neutron spectra of photoneutrons produced around an 18 MV linear accelerator for radiotherapy. Measurements were carried out with bare and Cd covered thermoluminescent dosimeters, TLD600 and TLD700, as well as inside a paraffine moderator. TLD pairs were also utilized as thermal neutrons inside a Bonner sphere spectrometer (au)

  3. Pulsed neutron source based on accelerator-subcritical-assembly

    Inoue, Makoto; Noda, Akira; Iwashita, Yoshihisa; Okamoto, Hiromi; Shirai, Toshiyuki [Kyoto Univ., Uji (Japan). Inst. for Chemical Research

    1997-03-01

    A new pulsed neutron source which consists of a 300MeV proton linac and a nuclear fuel subcritical assembly is proposed. The proton linac produces pulsed spallation neutrons, which are multipied by the subcritical assembly. A prototype proton linac that accelerates protons up to 7MeV has been developed and a high energy section of a DAW structure is studied with a power model. Halo formations in high intensity beam are also being studied. (author)

  4. The intense neutron generator and future factory type ion accelerators

    Lewis, W.B

    1968-07-01

    A neutron factory is likely to sell its product in the form of isotopes. To ay neutron factories are nuclear reactors. Ion accelerators may also produce isotopes by direct interaction and, at high enough energies, mesons and hyperons. The challenge of the electrical production of neutrons goes far beyond the isotope market. It challenges the two popular concepts for long term large scale energy, the fast breeder reactor and controlled thermonuclear fusion. For this use about 4% of nuclear generated power would be applied in a feedback loop generating extra neutrons. Competition rests on operating and processing costs. The Intense Neutron Generator proposal now cancelled would have been full scale for such a use, but much further advance in accelerator engineering is required and anticipated. Perhaps most promising is the application of the ion drag principle in which rings of fast electrons are accelerated along their axis dragging ions with them by electrostatic attraction. Due to the much larger mass of the ions they can acquire much higher energy than the electrons and the process could be efficient. Such accelerators have not yet been made but experimental and theoretical studies are promising. (author)

  5. The intense neutron generator and future factory type ion accelerators

    A neutron factory is likely to sell its product in the form of isotopes. To ay neutron factories are nuclear reactors. Ion accelerators may also produce isotopes by direct interaction and, at high enough energies, mesons and hyperons. The challenge of the electrical production of neutrons goes far beyond the isotope market. It challenges the two popular concepts for long term large scale energy, the fast breeder reactor and controlled thermonuclear fusion. For this use about 4% of nuclear generated power would be applied in a feedback loop generating extra neutrons. Competition rests on operating and processing costs. The Intense Neutron Generator proposal now cancelled would have been full scale for such a use, but much further advance in accelerator engineering is required and anticipated. Perhaps most promising is the application of the ion drag principle in which rings of fast electrons are accelerated along their axis dragging ions with them by electrostatic attraction. Due to the much larger mass of the ions they can acquire much higher energy than the electrons and the process could be efficient. Such accelerators have not yet been made but experimental and theoretical studies are promising. (author)

  6. Intense tera-hertz laser driven proton acceleration in plasmas

    Sharma, A.; Tibai, Z.; Hebling, J.

    2016-06-01

    We investigate the acceleration of a proton beam driven by intense tera-hertz (THz) laser field from a near critical density hydrogen plasma. Two-dimension-in-space and three-dimension-in-velocity particle-in-cell simulation results show that a relatively long wavelength and an intense THz laser can be employed for proton acceleration to high energies from near critical density plasmas. We adopt here the electromagnetic field in a long wavelength (0.33 THz) regime in contrast to the optical and/or near infrared wavelength regime, which offers distinct advantages due to their long wavelength ( λ = 350 μ m ), such as the λ 2 scaling of the electron ponderomotive energy. Simulation study delineates the evolution of THz laser field in a near critical plasma reflecting the enhancement in the electric field of laser, which can be of high relevance for staged or post ion acceleration.

  7. First-Order Particle Acceleration in Magnetically-driven Flows

    Beresnyak, Andrey; Li, Hui

    2016-03-01

    We demonstrate that particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. Some examples of such flows include spontaneous turbulent reconnection and decaying magnetohydrodynamic turbulence, where a magnetic field relaxes to a lower-energy configuration and transfers part of its energy to kinetic motions of the fluid. We show that this energy transfer, which normally causes turbulent cascade and heating of the fluid, also results in a first-order acceleration of non-thermal particles. Since it is generic, this acceleration mechanism is likely to play a role in the production of non-thermal particle distribution in magnetically dominant environments such as the solar chromosphere, pulsar magnetospheres, jets from supermassive black holes, and γ-ray bursts.

  8. Separations technology development to support accelerator-driven transmutation concepts

    This is the final report of a one-year Laboratory-Directed Research and Development (LDRD) Project at the Los Alamos National Laboratory (LANL). This project investigated separations technology development needed for accelerator-driven transmutation technology (ADTT) concepts, particularly those associated with plutonium disposition (accelerator-based conversion, ABC) and high-level radioactive waste transmutation (accelerator transmutation of waste, ATW). Specific focus areas included separations needed for preparation of feeds to ABC and ATW systems, for example from spent reactor fuel sources, those required within an ABC/ATW system for material recycle and recovery of key long-lived radionuclides for further transmutation, and those required for reuse and cleanup of molten fluoride salts. The project also featured beginning experimental development in areas associated with a small molten-salt test loop and exploratory centrifugal separations systems

  9. Thermal-hydraulic analysis of LBE spallation target for accelerator-driven systems

    Aniseh Ahmed Atef Abdalla; Jiyang Yu; Yongwel Yang

    2013-01-01

    In an accelerator-driven subcritical system (ADS), a high-performance spallation neutron source is used to feed the subcritical reactor. Neutron generation depends on the proton beam intensity. If the beam intensity is increased by a given factor, the number of generated neutrons will increase. The mechanism yielding a high rate of neutron production per energy is the spallation process, and this mechanism produces very high-energy deposition in the spallation target material. Producing a high rate of neutrons is accompanied by creation of problems of decay heat cooling and radiological protection. As a first step in designing a full-scale industrial ADS, a small-scale experimental ADS, which is similar to the European experimental ADS (XADS) is analysed. The analysis presented in this paper is based on lead–bismuth eutectic (LBE) cooled XADS-type experimental reactors, designed during the European experimental (PDS-XADS) project. Computational fluid dynamics analysis has been carried out for the spallation target. Steady-state behaviour and shear stress transport turbulence model with the automatic wall treatment were applied in the present analysis.

  10. OECD/Nea benchmark calculations for accelerator driven systems

    In order to evaluate the performances of the codes and the nuclear data, the Nuclear Science Committee of the OECD/NEA organised in July 1999 a benchmark exercise on a lead-bismuth cooled sub-critical system driven by a beam of 1 GeV protons. The benchmark model is based on the ALMR reference design and is optimised to burn minor actinides using a 'double strata' fuel cycle strategy. Seven organisations (ANL, CIEMAT, KAERI, JAERI, PSI/CEA, RIT and SCK-CEN) have contributed to this exercise using different basic data libraries (ENDF/B-VI, JEF-2.2 and JENDL-3.2) and various reactor calculation methods. Significant discrepancies are observed in important neutronic parameters, such as keff, reactivity swing with burn-up and neutron flux distributions. (author)

  11. Fast Neutron Radiography at an RFQ Accelerator System

    Daniels, G. C.; Franklyn, C. B.; Dangendorf, V.; Buffler, A.; Bromberger, B.

    This work introduces the Necsa Radio Frequency Quadrupole (RFQ) accelerator facility and its work concerning fast neutron radiography (FNR). Necsa operates a 4-5 MeV, up to 50 mA deuteron RFQ. The previous deuterium gas target station has been modified to enable producing a white neutron beam employing a solid B4C target. Furthermore, the high energy beam transport (HEBT) section is under adjustment to achieve a longer flight-path and a better focus. This work presents an overview of the facility, the modifications made, and introduces past and ongoing neutron radiography investigations.

  12. Linear induction accelerators for fusion and neutron production

    Linear induction accelerators (LIA) with pulsed power drives can produce high energy, intense beams or electrons, protons, or heavy ions with megawatts of average power. The continuing development of highly reliable LIA components permits the use such accelerators as cost-effective beam sources to drive fusion pellets with heavy ions, to produce intense neutron fluxes using proton beams, and to generate with electrons microwave power to drive magnetic fusion reactors and high gradient, rf-linacs

  13. Technology and Components of Accelerator-driven Systems. Second International Workshop Proceedings, Nantes, France, 21-23 May 2013

    The accelerator-driven system (ADS) is a potential transmutation system option as part of partitioning and transmutation strategies for radioactive waste in advanced nuclear fuel cycles. Following the success of the workshop series on the utilisation and reliability of the High Power Proton Accelerators (HPPA), the scope of this new workshop series on Technology and Components of Accelerator-driven Systems has been extended to cover subcritical systems as well as the use of neutron sources. The workshop organised by the OECD Nuclear Energy Agency provided experts with a forum to present and discuss state-of-the-art developments in the field of ADS and neutron sources. A total of 40 papers were presented during the oral and poster sessions. Four technical sessions were organised addressing ADS experiments and test facilities, accelerators, simulation, safety, data, neutron sources that were opportunity to present the status of projects like the MYRRHA facility, the MEGAPIE target, FREYA and GUINEVERE experiments, the KIPT neutron source, and the FAIR linac. These proceedings include all the papers presented at the workshop

  14. Investigation of neutron production by pyroelectric ion acceleration

    Highly sensitive experiments for direct Dark Matter searches, for example the CRESST experiment, are calibrated using neutrons. For this purpose one usually uses radioactive isotopes or tabletop linear accelerators. Both methods are not desirable in a CRESST-like experiment, because a radioactive source could cause contamination and the high voltage power supplies necessary for small accelerators disturb the detectors and electronics because of which measuring is no longer possible. A solution would be the high voltage generation using a pyroelectric crystal such as Lithiumtantalate. In this work it has been shown, that Lithiumtantalate generates high voltages of above 120,000 volt. Using this high voltage for field enhancement on nanotips, a sufficiently high field strength can be generated to allow field and tunneling ionization of deuterium molecules near the tip. If the high voltage has the correct polarity, the ions can be accelerated towards a deuterated target, for example deuterated polyethylene (CD2). On the target D(D,n)3He fusion is expected to take place with an energy dependent probability, producing monoenergetic neutrons with a kinetic energy of 2.45 MeV. The theoretical limit for neutrons produced with 100 kV acceleration voltage is almost 200 per second, however a realistic calculation resulted in about 1-10 neutrons per second. During this work a prototype of a pyroelectric accelerator was built and characterized. It was shown that a pyroelectric high voltage could be generated reliably with high reproducibility. Tungsten nanotips and carbon nanotubes were investigated with respect to their ionization properties. An ion current up to 1.2 nA was measured on target. A neutron detector system has been set up allowing to detect extremely low neutron fluxes generated in the accelerator. The absolute detection efficiency for neutrons created by the fusion reaction is presently at 2.5%. With suitable analysis tools which were developed during this work

  15. Investigation of subcritical multiplication parameters in TRIGA Mark II accelerator driven system

    Highlights: • TRIGA ADS neutron external source was numerically investigated. • Source target material, radius, position, and incident beam energy were studied. • Maximum neutron yield for W, Pb, and W–Cu targets are at radii 3.25, 3.5 and 7 cm. • Maximum source efficiency for targets at the given core is achieved at the center. • Maximum source efficiency is achieved at 40 MeV incident electron beam energy. - Abstract: The accelerator driven system (ADS) is a very interesting option to improve the safety of nuclear power reactor and for transmutation of spent fuel. The Texas phase of the reactor–accelerator coupling experiment (RACE), completed in March 2006, demonstrated the feasibility of operating a training research isotopes general atomic (TRIGA) research reactor in a subcritical configuration driven to a significant power by an electron LINAC neutron source (photoneutron). In the present study, the effects of changing the source cylindrical target material, radius, position and the electron beam energy on the final neutron production, fission probability, and the subcritical system multiplication of TRIGA Mark II research reactor, have been numerically investigated. Three target materials are used: Tungsten, Lead and Tungsten–Copper alloy, while varying the target radius from 2 to 8 cm, the source position at three locations, and the beam energy from 10 to 55 MeV. The investigation is based on the numerical calculation of the subcritical multiplication factor and the external source efficiency using Monte Carlo MCNPX code. Through the comparison of the studied cases results, the favorable target material and radius, source position, and beam energy can be obtained

  16. Monte Carlo simulation for calculation of kinetic parameters in an Accelerator Driven Subcritical TRIGA reactor

    Highlights: • Among the kinetic parameters, the most important ones are βeff and Λ. • Several methods including the Rossi-α and Feynman-α techniques, slope fit and MCNPX code have been investigated. • The Monte Carlo MCNPX code was used to simulate a geometrical model of the TRIGA core. • The results of the methods have been validated. - Abstract: In this study, noise analysis techniques including Feynman-α (variance-to-mean) and Rossi-α (correlation) and dynamic method such as slope fit method have been used to calculate effective delayed neutron fraction (βeff) and neutron reproduction time (Λ) in Accelerator Driven Subcritical TRIGA reactor. The obtained results have been compared with MCNPX code results. The relative difference between MCNPX code with Feynman-α and Rossi-α techniques and slope fit method for βeff are approximately −5.4%, 1.2%, and −10.6%, −14.8%, respectively, and also for Λ is approximately 2.1%. According to results, the noise methods can been considered ideal for detection with high efficiency and zero dead time and in the slope fit method, the decay of the delayed neutrons has been neglected and only the prompt neutrons have been taken into account. In addition, quantities simulated in the current study are validated against both the reference data and the results of MCNPX code. Therefore, the purpose of this study is to simulate the commonly used experimental methods by MCNPX code and investigate the convergence as well as accuracy of the computational results for different analysis methods in calculation of the kinetic parameters in an Accelerator Driven Subcritical TRIGA reactor

  17. Accelerated Ions from a Laser Driven Z-pinch

    Helle, Michael H; Kaganovich, Dmitri; Chen, Yu-hsin; Palastro, John P; Ting, Antonio

    2015-01-01

    Intense laser acceleration of ions is inherently difficult due to the velocity mismatch between laser pulses moving at the speed of light and slowly moving massive ions. Instead of directly accelerating the ions, current approaches rely on TV/m laser fields to ionize and drive out electrons. The ions are then accelerated by the resulting electrostatic fields from charge separation. Here we report experimental and numerical acceleration of ions by means of laser driven Z-pinch exiting a sharp plasma interface. This is achieved by first driving a plasma wakefield in the self-modulated bubble regime. Cold return currents are generated to maintain quasi-neutrality of the plasma. The opposite current repel and form an axial fast current and a cylindrical-shell cold return current with a large (100 MG) azithmuthal field in between. These conditions produce a Z-pinch that compresses the fast electrons and ions on axis. If this process is terminated at a sharp plasma interface, a beam of ions are then accelerated in ...

  18. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning or transmutation of commercial spent fuel or energy production from thorium. The experiment will be operated at power levels up to 5 MWt

  19. Advanced approaches to high intensity laser-driven ion acceleration

    Since the pioneering work that was carried out 10 years ago, the generation of highly energetic ion beams from laser-plasma interactions has been investigated in much detail in the regime of target normal sheath acceleration (TNSA). Creation of ion beams with small longitudinal and transverse emittance and energies extending up to tens of MeV fueled visions of compact, laser-driven ion sources for applications such as ion beam therapy of tumors or fast ignition inertial con finement fusion. However, new pathways are of crucial importance to push the current limits of laser-generated ion beams further towards parameters necessary for those applications. The presented PhD work was intended to develop and explore advanced approaches to high intensity laser-driven ion acceleration that reach beyond TNSA. In this spirit, ion acceleration from two novel target systems was investigated, namely mass-limited microspheres and nm-thin, free-standing diamond-like carbon (DLC) foils. Using such ultrathin foils, a new regime of ion acceleration was found where the laser transfers energy to all electrons located within the focal volume. While for TNSA the accelerating electric field is stationary and ion acceleration is spatially separated from laser absorption into electrons, now a localized longitudinal field enhancement is present that co-propagates with the ions as the accompanying laser pulse pushes the electrons forward. Unprecedented maximum ion energies were obtained, reaching beyond 0.5 GeV for carbon C6+ and thus exceeding previous TNSA results by about one order of magnitude. When changing the laser polarization to circular, electron heating and expansion were shown to be efficiently suppressed, resulting for the first time in a phase-stable acceleration that is dominated by the laser radiation pressure which led to the observation of a peaked C6+ spectrum. Compared to quasi-monoenergetic ion beam generation within the TNSA regime, a more than 40 times increase in

  20. Advanced approaches to high intensity laser-driven ion acceleration

    Henig, Andreas

    2010-04-26

    Since the pioneering work that was carried out 10 years ago, the generation of highly energetic ion beams from laser-plasma interactions has been investigated in much detail in the regime of target normal sheath acceleration (TNSA). Creation of ion beams with small longitudinal and transverse emittance and energies extending up to tens of MeV fueled visions of compact, laser-driven ion sources for applications such as ion beam therapy of tumors or fast ignition inertial con finement fusion. However, new pathways are of crucial importance to push the current limits of laser-generated ion beams further towards parameters necessary for those applications. The presented PhD work was intended to develop and explore advanced approaches to high intensity laser-driven ion acceleration that reach beyond TNSA. In this spirit, ion acceleration from two novel target systems was investigated, namely mass-limited microspheres and nm-thin, free-standing diamond-like carbon (DLC) foils. Using such ultrathin foils, a new regime of ion acceleration was found where the laser transfers energy to all electrons located within the focal volume. While for TNSA the accelerating electric field is stationary and ion acceleration is spatially separated from laser absorption into electrons, now a localized longitudinal field enhancement is present that co-propagates with the ions as the accompanying laser pulse pushes the electrons forward. Unprecedented maximum ion energies were obtained, reaching beyond 0.5 GeV for carbon C{sup 6+} and thus exceeding previous TNSA results by about one order of magnitude. When changing the laser polarization to circular, electron heating and expansion were shown to be efficiently suppressed, resulting for the first time in a phase-stable acceleration that is dominated by the laser radiation pressure which led to the observation of a peaked C{sup 6+} spectrum. Compared to quasi-monoenergetic ion beam generation within the TNSA regime, a more than 40 times

  1. Development of an accelerating-piston implosion-driven launcher

    Huneault, Justin; Loiseau, Jason; Higgins, Andrew

    2013-06-01

    The ability to soft-launch projectiles at velocities exceeding 10 km/s is of interest to several scientific fields, including orbital debris impact testing and equation of state research. Current soft-launch technologies have reached a performance plateau below this operating range. The energy and power density of high explosives provides a possible avenue to reach this velocity if used to dynamically compress a light driver gas to significantly higher pressures and temperatures compared to light-gas guns. In the implosion-driven launcher (IDL), linear implosion of a pressurized tube drives a strong shock into the gas ahead of the tube pinch, thereby forming an increasingly long column of compressed gas which can be used to propel a projectile. The McGill IDL has demonstrated the ability to launch a 0.1-g projectile to 9.1 km/s. This study focuses on the implementation of a novel launch cycle wherein the explosively driven pinch is accelerated down the length of the tube in order to maintain a relatively constant projectile base pressure early in the launch cycle. The experimental development of an accelerating driver which utilizes an explosive lens to phase the detonation wave is presented. The design and experimental performance of an accelerating-piston IDL is also discussed.

  2. Occupational dose due to neutrons in medical linear accelerators

    This paper describes a semi-empirical method to calculate the occupational dose due to neutrons and capture gamma rays in medical linear accelerators. It compares theoretical dose values with measurements performed in several 15 MeV medical accelerators installed in the country. Good agreement has been found between calculations made using the model and dose measurements, except for those accelerator rooms in which the maze length was shorter than the postulated tenth value distance. For those cases the model seems to overestimate neutron dose. The results demonstrate that the semi-empirical model is a good tool for quick and conservative shielding calculations for radiation protection purposes. Nevertheless, it is necessary to continue with the measurements in order to perform a more accurate validation of the model. (author)

  3. Transformer ratio saturation in a beam-driven wakefield accelerator

    Farmer, J. P.; Martorelli, R.; Pukhov, A. [Institut für Theoretische Physik I, Heinrich Heine Universität, 40225 Düsseldorf (Germany)

    2015-12-15

    We show that for beam-driven wakefield acceleration, the linearly ramped, equally spaced train of bunches typically considered to optimise the transformer ratio only works for flat-top bunches. Through theory and simulation, we explain that this behaviour is due to the unique properties of the plasma response to a flat-top density profile. Calculations of the optimal scaling for a train of Gaussian bunches show diminishing returns with increasing bunch number, tending towards saturation. For a periodic bunch train, a transformer ratio of 23 was achieved for 50 bunches, rising to 40 for a fully optimised beam.

  4. Stochastic acceleration of ions driven by Pc1 wave packets

    The stochastic motion of protons and He+ ions driven by Pc1 wave packets is studied in the context of resonant particle heating. Resonant ion cyclotron heating typically occurs when wave powers exceed 10−4 nT2/Hz. Gyroresonance breaks the first adiabatic invariant and energizes keV ions. Cherenkov resonances with the electrostatic component of wave packets can also accelerate ions. The main effect of this interaction is to accelerate thermal protons to the local Alfven speed. The dependencies of observable quantities on the wave power and plasma parameters are determined, and estimates for the heating extent and rate of particle heating in these wave-particle interactions are shown to be in reasonable agreement with known empirical data

  5. Analysis of burn up effects on kinetic parameters in an Accelerator Driven Subcritical TRIGA reactor

    Highlights: • Among the kinetic parameters, the most important ones are βeff and Λ. • The kinetic parameters at the end of cycle for 20 days operation at 1 MW reactor power have been calculated using MCNPX code. • The system sub-criticality levels, the required accelerator current and power have been calculated for each burnup step. • Burnup effects on neutronic parameters and accelerator requirements are analysed for a life cycle of the reactor core. - Abstract: In this paper, the kinetic parameters at the end of cycle for 20 days operation at 1 MW reactor power have been calculated using MCNPX code for source multiplication factors (Ks) of critical and 0.97 levels. Accelerator Driven Subcritical TRIGA reactor has been considered as the case study of the problem. The system sub-criticality levels, the required accelerator current (Ip) and power (Pacc) have been calculated for each burn up step. According to the results, the required Ip and Pacc increased as system sub-criticality level decreased. Also, the results show that the effective delayed neutron fraction (βeff) does not depend on sub-criticality levels significantly but the neutron reproduction time (Λ) strongly depends on the number of fuel elements in the core and sub-criticality levels. In addition, it was observed that in comparison with the beginning-of-cycle values, at end-of-cycle, the Λ increases by 112.6% and 108.4% respectively but the βeff decreases by 6.1% and 1.8% respectively in critical and 0.97 levels

  6. Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams

    Schroeder, C. B.

    2011-01-01

    Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. The implications for accelerator design and the different physical mechanisms of laser-driven and beam-driven plasma acceleration are discussed. Driver propagation is examined, as well as the effects of the excited plasma wave phase velocity. The driver coupling to subsequent plasma accelerator stages for high-energy physics applications is addressed.

  7. Deuteron and neutron induced activation in the Eveda accelerator materials: implications for the accelerator maintenance

    Garcia, M.; Sanz, J.; Garcia, N.; Cabellos, O. [Madrid Univ. Politecnica, C/ Jose Gutierrez Abascal, lnstituto de Fusion Nuclear (Spain); Sauvan, R. [Universidad Nacional de Educacion a Distancia (UNED), Madrid (Spain); Moreno, C.; Sedano, L.A. [CIEMAT-Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Association Euratom-CIEMAT, Madrid (Spain)

    2007-07-01

    Full text of publication follows: The IFMIF (International Fusion Materials Irradiation Facility) is an accelerator-based DLi neutron source designed to test fusion reactor candidate materials for high fluence neutrons. Before deciding IFMIF construction, an engineering design and associated experimental data acquisition, defined as EVEDA, has been proposed. Along the EVEDA accelerator, deuteron beam losses collide with the accelerator materials, producing activation and consequent radiations responsible of dose. Calculation of the dose rates in the EVEDA accelerator room is necessary in order to analyze the feasibility for manual maintenance. Dose rates due to the activation produced by the deuteron beam losses interaction with the accelerator materials, will be calculated with the ACAB activation code, using EAF2007 library for deuteron activation cross-sections. Also, dose rates from the activation induced by the neutron source produced by the interaction of deuteron beam losses with the accelerator materials and the deuterium implanted in the structural lattice, will be calculated with the SRIM2006, TMAP7, DROSG2000/NEUYIE, MCNPX and ACAB codes. All calculations will be done for the EVEDA accelerator with the room temperature DTL structure, which is based on copper cavities for the DTL. Some calculations will be done for the superconducting DTL structure, based on niobium cavities for the DTL working at cryogenic temperature. Final analysis will show the dominant mechanisms and major radionuclides contributing to the surface dose rates. (authors)

  8. Deuteron and neutron induced activation in the Eveda accelerator materials: implications for the accelerator maintenance

    Full text of publication follows: The IFMIF (International Fusion Materials Irradiation Facility) is an accelerator-based DLi neutron source designed to test fusion reactor candidate materials for high fluence neutrons. Before deciding IFMIF construction, an engineering design and associated experimental data acquisition, defined as EVEDA, has been proposed. Along the EVEDA accelerator, deuteron beam losses collide with the accelerator materials, producing activation and consequent radiations responsible of dose. Calculation of the dose rates in the EVEDA accelerator room is necessary in order to analyze the feasibility for manual maintenance. Dose rates due to the activation produced by the deuteron beam losses interaction with the accelerator materials, will be calculated with the ACAB activation code, using EAF2007 library for deuteron activation cross-sections. Also, dose rates from the activation induced by the neutron source produced by the interaction of deuteron beam losses with the accelerator materials and the deuterium implanted in the structural lattice, will be calculated with the SRIM2006, TMAP7, DROSG2000/NEUYIE, MCNPX and ACAB codes. All calculations will be done for the EVEDA accelerator with the room temperature DTL structure, which is based on copper cavities for the DTL. Some calculations will be done for the superconducting DTL structure, based on niobium cavities for the DTL working at cryogenic temperature. Final analysis will show the dominant mechanisms and major radionuclides contributing to the surface dose rates. (authors)

  9. Monte Carlo Modeling of Fast Sub-critical Assembly with MOX Fuel for Research of Accelerator-Driven Systems

    Polanski, A.; Barashenkov, V.; Puzynin, I.; Rakhno, I.; Sissakian, A.

    It is considered a sub-critical assembly driven with existing 660 MeV JINR proton accelerator. The assembly consists of a central cylindrical lead target surrounded with a mixed-oxide (MOX) fuel (PuO2 + UO2) and with reflector made of beryllium. Dependence of the energetic gain on the proton energy, the neutron multiplication coefficient, and the neutron energetic spectra have been calculated. It is shown that for subcritical assembly with a mixed-oxide (MOX) BN-600 fuel (28%PuO 2 + 72%UO2) with effective density of fuel material equal to 9 g/cm 3 , the multiplication coefficient keff is equal to 0.945, the energetic gain is equal to 27, and the neutron flux density is 1012 cm˜2 s˜x for the protons with energy of 660 MeV and accelerator beam current of 1 uA.

  10. Design of an accelerator-based neutron source for neutron capture therapy

    The boron neutron capture therapy is mainly suited in the treatment of some tumor kinds which revealed ineffective to the traditional radiotherapy. In order to take advantage of such a therapeutic modality in hospital environments, neutron beams of suitable energy and flux levels provided by compact size facilities are needed. The advantages and drawbacks of several neutron beams are here analysed in terms of therapeutic gains. In detail the GEANT-3/MICAP simulations show that high tumor control probability, with sub-lethal dose at healthy tissues, can be achieved by using neutron beams of few keV energy having a flux of about 109 neutrons/(cm2 s). To produce such a neutron beam, the feasibility of a proton accelerator is investigated. In particular an appropriate choice of the radiofrequency parameters (modulation, efficiency of acceleration, phase shift, etc.) allows the development of relatively compact accelerators, having a proton beam current of 30 mA and an energy of 2 MeV, which could eventually lead to setting up of hospital-based neutron facilities.