Download or read book Calculations of Radiation Damage in Target Container and Window Materials for Spallation Neutron Sources written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials Considerations for the National Spallation Neutron Source Target written by and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The National Spallation Neutron Source (NSNS), in which neutrons are generated by bombarding a liquid mercury target with 1 GeV protons, will place extraordinary demands on materials performance. The target structural material will operate in an aggressive environment, subject to intense fluxes of high energy protons, neutrons, and other particles, while exposed to liquid mercury and to water. Components that require special consideration include the Hg liquid target container and protective shroud, beam windows, support structures, moderator containers, and beam tubes. In response to these demands a materials R and D program has been developed for the NSNS that includes: selection of materials; calculations of radiation damage; irradiations, post irradiation testing, and characterization; compatibility testing and characterization; design and implementation of a plan for monitoring of materials performance in service; and materials engineering and technical support to the project. Irradiations are being carried out in actual and simulated spallation environments. Compatibility experiments in Hg are underway to ascertain whether the phenomena of liquid metal embrittlement and temperature gradient mass transfer will be significant. Results available to date are assessed in terms of the design and operational performance of the facility.
Download or read book Materials Consideration for the National Spallation Neutron Source Target written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The National Spallation Neutron Source (NSNS), in which neutrons are generated by bombarding a liquid mercury target with 1 GeV protons, will place extraordinary demands on materials performance. The target structural material will operate in an aggressive environment, subject to intense fluxes of high energy protons, neutrons, and other particles, while exposed to liquid mercury and to water. Components that require special consideration include the Hg liquid target container and protective shroud, beam windows, support structures, moderator containers, and beam tubes. In response to these demands a materials R and D program has been developed for the NSNS that includes: selection of materials; calculations of radiation damage; irradiations, post-irradiation testing, and characterization; compatibility testing and characterization; design and implementation of a plan for monitoring of materials performance in service; and materials engineering and technical support to the project. Irradiations are being carried out in actual and simulated spallation environments. Compatibility experiments in Hg are underway to ascertain whether the phenomena of liquid metal embrittlement and temperature gradient mass transfer will be significant. Results available to date are assessed in terms of the design and operational performance of the facility.
Download or read book Transactions of the American Nuclear Society written by American Nuclear Society and published by . This book was released on 1998 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamental Physics with Pulsed Neutron Beams written by Christopher R. Gould and published by World Scientific. This book was released on 2001 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low energy neutron beams are used to address many questions in nuclear physics, particle physics and astrophysics. The scientific issues include elucidating the nature of time reversal noninvariance; understanding the origin of the baryon asymmetry in the Universe; describing the weak interaction between quarks and between nucleons; understanding the origin of the elements in stellar and big bang nucleosynthesis.This book summarizes how spallation neutron sources work and discuss the advantages of pulsed beams in reducing systematic errors in precision measurements. It also describes recent breakthroughs in ultracold neutron production, together with the physics that will be addressed by the new generation of intense neutron sources.
Download or read book Spallation Radiation Damage and Dosimetry for Accelerator Transmutation of Waste Applications written by and published by . This book was released on 1993 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proposals are currently being made for systems to treat radioactive waste based on the use of accelerator-driven neutron sources. A linear proton accelerator with energies as high as 1600 MeV and currents up to 250 ma are anticipated for the driver. The neutron fluxes may reach up to 102° neutrons/m2s as generated by the spallation reactions that occur when the protons strike target materials. Calculations are described to determine radiation fluxes and flux spectra inherent in such systems and to estimate likely radiation effects on system components. The calculations use LAHET, a Monte Carlo high-energy transport code, and MCNP, a generalized-geometry, coupled neutron-photon Monte Carlo transport code. Cross sections for displacement and helium production are presented for spallation neutrons of energies from 21 MeV to 1600 MeV for Inconel 718 (Ni plus 18.5, 18.5, 5.1, and 3 wt % of Cr, Fe, Nb, and Mo, respectively), an alloy that is used for the proton beam entry window in several accelerators. In addition, results for this alloy are presented for the primary knocked-on atom (PKA) spectrum and the transmutation yield for 1600 MeV incident neutrons.
Download or read book Spallation Radiation Damage and Dosimetry for Accelerator Transmutation of Waste Applications written by MS. Wechsler and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proposals are currently being made for systems to treat radioactive waste based on the use of accelerator-driven neutron sources. A linear proton accelerator with energies as high as 1600 MeV and currents up to 250 ma are anticipated for the driver. The neutron fluxes may reach up to 1020 neutrons/m2s as generated by the spallation reactions that occur when the protons strike target materials. Calculations are described to determine radiation fluxes and flux spectra inherent in such systems and to estimate likely radiation effects on system components. The calculations use LAHET, a Monte Carlo high-energy transport code, and MCNP, a generalized-geometry, coupled neutron-photon Monte Carlo transport code. Cross sections for displacement and helium production are presented for spallation neutrons of energies from 21 MeV to 1600 MeV for Inconel 718 (Ni plus 18.5, 18.5, 5.1, and 3 wt% of Cr, Fe, Nb, and Mo, respectively), an alloy that is used for the proton beam entry window in several accelerators. In addition, calculations for this alloy are presented for the primary knocked-on atom (PKA) spectrum and the transmutation yield for 1600 MeV incident neutrons.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book STIP VI TARGET 9 RADIATION DAMAGE ASSESSMENT BASED ON A MCNPX SIMULATION written by David Aulet Prieto and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The SINQ Target Irradiation Program (STIP) has been developed at Paul Scherrer Institute (PSI) during the last twenty years. It is aimed to analyze the radiation damage induced by spallation reactions in different structural materials. It is also providing relevant data for developing future spallation sources as well as advanced spallation targets. STIP VI was conducted in SINQ Target 9 during 2011/2012 receiving a total proton charge of 13.16 Ah. The Monte Carlo N-Particle eXtended code (MCNPX) is used for implementing the model and performing the simulation to obtain the proton and neutron fluences as well as the energy deposition in the different points of interest. Afterwards, this information is used for calculating the displacement per atom (dpa) plus the Helium and Hydrogen production in atomic parts per million (appm). The results will contribute to understand the irradiation effect in different structural materials. It will also be useful for comparing it with the real radiation damage measurements of the irradiated materials after its cool down period. The target mainly consists of the AlMg3 inverted semi-sphere Beam Entrance Window (BEW) and the cylindrical Rod Container Box (RCB) which keeps inside 306 rods fitting 36 rows. There is also the Safety Hull Tube (SHT), made of AlMg3, which consists of a double cylinder walls surrounding the RCB and linked to the inverted BEW at the bottom. The source definition is implemented in the MCNPX input file from the gamma mapping performed at the irradiated Target 9. The material specification of the specimen rods is implemented by taking its average composition, assuming a uniform distribution. The maximum proton flux obtained at the inverted BEW is 1.75x1014 p/(cm2 ·s·mA). The maximum proton fluence in the target is obtained in Row 0 becoming 8.33x1025 p/m2 . The maximum neutron fluence is obtained in Row 8 with a value of 1.99x1026 n/m2 , which in flux units stands for 4.19x1014 n/(cm2 ·s·mA). Regarding the SHT, the maximum proton flux escaping from the target is obtained above Row 36 with a value of 5.99x1011 p/(cm2 ·s·mA) and the maximum neutron flux is escaping around the middle part of the target with a value of 1.39x1014 n/(cm2 ·s·mA). The maximum energy deposition in Zircaloy-2 cladding tubes is obtained in the center rod placed in Row 2 with a value of 400.32 W/(cm3 ·mA). Page 2 The irradiation parameters have been calculated by multiplying the proton and neutron fluence with its corresponding material cross section data. The results obtained at the center of the inverted BEW are 8.85 dpa, 2447 appm He and 4854 appm H. For the SHT, the maximum values of the irradiation parameters are obtained around the middle part of the target with the following values: 3.14 dpa, 17.63 appm He and 71.64 appm H. Finally, the maximum displacement per atom in the specimen rods is obtained for Zircaloy-2 in Rod 1, placed in Row 2, with a value of 72.07 dpa and the maximum Helium & Hydrogen concentration are obtained for Tantalum in Rod A, placed in Row 1, with the following values: 3629 appm He and 17418 appm H.
Download or read book Energy Deposition and Damage Calculations in Core Vessel Inserts at the Spallation Neutron Source written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat-deposition and damage calculations are described for core-vessel inserts in the target area of the Spallation Neutron Source. Two separate designs for these inserts (or neutron beam tubes) were studied; a single-unit insert and a multi-unit insert. The single unit contains a neutron guide; the multi unit does not. Both units are constructed of stainless steel. For the single unit, separate studies were carried out with the guide composed of stainless steel, glass, and aluminum. Results are also reported for an aluminum window on the front of the insert, a layer of nickel on the guide, a cadmium shield surrounding the guide, and a stainless steel plug in the beam-tube opening. The locations of both inserts were the most forward positions to be occupied by each design respectively thus ensuring that the calculations are conservative.
Download or read book Review written by Oak Ridge National Laboratory and published by . This book was released on 1996 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spallation Radiation Damage Calculations and Database written by Monroe S. Wechsler and published by . This book was released on 2006 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A radiation damage database at NCSU is described that contains, at present, cross sections for damage energy, displacements, helium, and hydrogen. For neutrons and protons at 20-3200 MeV energies, the targets include 23 target elements from Mg to U and eight practical alloys. The underlying calculations employ Bertini, ISABEL, and CEM2k intranuclear cascade models as provided within MCNPX, three level-density formulations (GCCI, HETC, and Jülich), and multistage pre-equilibrium model (MPM) on and off. The database also includes radiation damage cross sections for lower-energy neutrons and protons, as obtained from LA150, SPECTER, ENDF, and SRIM. Examples of the database contents are provided with regard to damage energy and displacement cross sections for neutrons on Al, Fe, and W. Also, neutron flux and displacement rate calculations are described for neutrons on Fe and the 316 stainless steel mercury container vessel at SNS. In addition, discrepancies between the codes are discussed.
Download or read book Radiation Protection and Shielding written by Isabel F. Gonçalves and published by . This book was released on 2005 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Specialists Meeting on Shielding Aspects of Accelerators Targets and Irradiation Facilities written by and published by . This book was released on 1998 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Irradiation Damage of Ferritic written by and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferritic/martensitic steels were chosen as candidates for future fusion power plants because of their superior swelling resistance and better thermal properties than austenitic stainless steels. For the same reasons, these steels are being considered for the target structure of a spallation neutron source, where the structural materials will experience even more extreme irradiation conditions than expected in a fusion power plant first wall (i.e., high-energy neutrons that produce large amounts of displacement damage and transmutation helium). Extensive studies on the effects of neutron irradiation on the mechanical properties of ferritic/martensitic steels indicate that the major problem involves the effect of irradiation on fracture, as determined by a Charpy impact test. There are indications that helium can affect the impact behavior. Even more helium will be produced in a spallation neutron target material than in the first wall of a fusion power plant, making helium effects a prime concern for both applications. 39 refs., 10 figs.
Download or read book INIS Atomindex written by and published by . This book was released on 1996 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt:
