Download or read book Design Construction and Characterization of a Fast Neutron Beam Port Facility at the University of Texas at Austin TRIGA Reactor written by Daniel Caldwell Barron and published by . This book was released on 2018 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fast neutron irradiation facility has been designed, modeled, and constructed in the beam port 4 facility at The University of Texas at Austin’s TRIGA Mark-II Reactor. This facility targets the Watt-fission neutron spectrum in a controlled environment by reducing the present thermal and epithermal flux while preserving the fast neutron flux. The present facility will open new avenues in nuclear non-proliferation for fast-fission yields in addition to measuring radionuclide migration. The filter system was designed using MCNP and Solidworks and consists of a lead plug to stop gamma-rays, filter elements of natural boron and 96% enriched B10, collimation elements of borated polyethylene and natural boron, and an exit filter of boron nitride. A beam stop was constructed to reduce the ambient dose rate using borated paraffin wax, polyethylene, cadmium, and lead. Sensitivity studies were performed to configure an economic facility by optimizing the amounts and configurations of materials used in the filter. The filter is modular to allow for rearrangement of elements and the ability to change the materials used as needed should higher efficiencies be desired or a higher total flux. Initial results indicate the facility produces a 10 cm diameter beam with an integrated flux of 6.63x105 n/cm2/s at a reactor power of 950 kW and resembles the Watt-fission spectrum well with a slightly elevated epithermal neutron flux. The fast neutron flux above 0.1 MeV constitutes 98.77% of the total flux and the thermal neutron flux only 0.0014% of the total flux. STAYSL PNNL was used to unfold the neutron spectrum from 9 measurable reactions in 5 flux foils. Results suggest that the fast neutron flux is higher than anticipated in all STAYSL runs although the total flux is lower than anticipated.

Download or read book Design Construction and Characterization of an External Neutron Beam Facility at The Ohio State University Nuclear Reactor Laboratory written by Danyal J. Turkoglu and published by . This book was released on 2012 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The objective of this research was to bring a thermal neutron beam facility to the Ohio State University Nuclear Reactor Laboratory for the purposes of neutron-based research. The neutron beam is extracted from the reactor core through a neutron collimator emplaced in Beam Port #2, the radial beam port facing the core at a 30° angle. The collimator is an aluminum tube containing components designed to filter and shape the neutron beam. The filters are poly-crystalline bismuth (10.16 cm thickness, 12.7 cm diameter) for significantly reducing gamma ray content and single-crystal sapphire (12.7 cm thickness, 10.16 cm diameter) for preferentially passing thermal neutrons while scattering more energetic neutrons out of the beam. The thermal neutron beam is defined by multiple 3.0 cm diameter apertures in borated aluminum. Apertures in polyethylene-based disks and in Pb disks provide shielding for fast neutrons and gamma rays, respectively, in the neutron collimator. Characterization of the beam was performed using foil activation analysis to find the neutron flux and a low-cost digital neutron imaging apparatus to "see" the beam profile. The neutron collimator delivers the filtered thermal neutron beam with a 3.5 cm diameter umbra and a thermal neutron equivalent flux of (8.55 +̲ 0.19) x 106 cm−2s−1 at 450 kW reactor power (90% of rated limit) to the sample location. The beam is highly thermalized with a cadmium ratio of 266 +̲ 13. The facility was designed for neutron depth profiling, a nondestructive analytical technique for finding the concentration versus depth in the near surface (tens of microns) for isotopes that undergo charged particle emitting reactions, such as 10B(n, 4He)7Li, 6Li (n, 3H)4He, and 3He (n, 1H)3H, to name a few.

Download or read book Neutron Beam Design Development and Performance for Neutron Capture Therapy written by Otto K. Harling and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: For this Workshop, the organizers have attempted to invite experts from all known centers which are engaged in neutron beam development for neutron capture therapy. The Workshop was designed around a series of nineteen invited papers which dealt with neutron source design and development and beam characterization and performance. Emphasis was placed on epithermal beams because they offer clinical advantages and are more challenging to implement than thermal beams. Fission reactor sources were the basis for the majority of the papers; however three papers dealt with accelerator neutron sources. An additional three invited papers provided a summary of clinical results of Ncr therapy in Japan between 1968 and 1989 and overviews of clinical considerations for neutron capture therapy and of the status of tumor targeting chemical agents for Ncr. Five contributed poster papers dealing with NCT beam design and performance were also presented. A rapporteurs' paper was prepared after the Workshop to attempt to summarize the major aspects, issues, and conclusions which resulted from this Workshop. Many people contributed to both the smooth functioning of the Workshop and to the preparation of these proceedings. Special thanks are reserved for Ms. Dorothy K.

Download or read book Design and Development of an External Fast Neutron Beam Facility at the Ohio State University Research Reactor written by Andrew M. Zapp and published by . This book was released on 2019 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability of the Ohio State University Research Reactor, OSURR, to conduct experiments from the generation of the neutron flux is important in conducting research by the University and external entities that require a flux of this magnitude. In particular, research involving a fast neutron flux is of interest due to the different interactions fast neutrons have as opposed to thermal neutrons. The OSURR is able to operate up to 500 kW, which creates a neutron flux in the order of 1013 n/cm2-s. Currently, Beam Port 2 provides a thermal neutron beam profile of 30 mm in diameter for experimentation such as neutron depth profiling, activation analysis, and evaluation of radiation damage to electronics. Beam Port 1 uses a sample area located adjacent and perpendicular to the fuel plates of the reactor for in-core irradiation. During experimentation, the remainder of Beam Port 1 must be plugged with removable concrete shielding to prevent radiation exposure that can be upwards of 1x104 rem/hr. The upgrade to Beam Port 1 consists of a collimator to shape the neutron flux from the reactor into a beam of fast neutrons, similar in diameter to Beam Port 2, in order to irradiate samples external to the reactor. In addition, mobile external shielding is designed to prevent exceeding the exposure limits of 5 rem/yr when the facility is in use. With this upgrade the research reactor has the ability to conduct simultaneous experiments with a fast and thermal neutron beam, external to the biological shielding, without releasing any harmful exposure.

Download or read book Design Development Characterization and Application of a New Neutron Imaging Facility at the Penn State Breazeale Reactor written by Alibek Kenges and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron imaging is a powerful tool in the field of non-destructive testing that utilizes unique attenuation properties of neutrons allowing through-images of some high-density objects. The Radiation Science and Engineering Center (RSEC) has had a neutron imaging facility for the last several decades. With the installation of a new core moderator assembly and new beam ports at the RSEC -- the Penn State Breazeale Reactor (PSBR) in 2018, a dedicated neutron beam port became available for a new neutron imaging facility at RSEC (RSEC -- NIF). The initial design of the beam port designated for the RSEC -- NIF was of divergent type that needed to be upgraded by means of collimator components and filters. After a thorough investigation of existing neutron imaging facilities around the world, it has been decided to collimate the beam port with convergent and divergent collimators and to filter the gamma and neutron content with the single crystal bismuth and sapphire filters. A set of system characterization experiments were conducted at the RSEC -- NIF that confirmed the system's correspondence to a Category I facility by ASTM standards. In addition to that, the collimation ratio of the new system was measured following the procedures given in the ASTM protocols and resulted in the effective L/D ratio value between 107 and 115. The thermal flux across the exit surface from the beam port at the biological shield was measured to be equal to 5.4E+06 n/cm^2-s at 1MWth reactor power. The application of the RSEC -- NIF's capabilities in neutron radiography (NR) and tomography (NT) techniques were demonstrated imaging different types of environmental samples for the presence and visualization of microplastic particles. Preliminary results of NT experiments conducted at the RSEC -- NIF have shown that this technique can be used as an intermediary step to visualize the content and spatial distribution of microplastics in the sand columns. Additionally, the NR capabilities of the RSEC -- NIF were utilized to visualize the microplastic particles in the sediment samples and used water filters. All obtained results and the continuation of research in this direction can potentially shed some light in the general research of microplastic transport mechanisms in different terrestrial and aquatic ecosystems.

Download or read book Characteristics of the LPTR Fast Neutron Irradiation Facility written by Garth E. Cummings and published by . This book was released on 1963 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Design and Construction of a Cold Neutron Source for Use in the Cornell University Triga Reactor written by Lydia Jane Young and published by . This book was released on 1983 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of the Epithermal Pneumatic Tube EPNT and Beam Port 1 5 at the University of Texas at Austin written by Shelby Hobohm and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, experiments were conducted to characterize the neutron flux spectra at two locations of the University of Texas at Austin’s TRIGA reactor: the cadmium-shielded epithermal pneumatic tube (EPNT) and the Beam Port 1-5 (BP 1-5) irradiation locations. Two sets of activation foils, one for each location, were carefully selected and irradiated ensuring that the full neutron energy range was included. The NJOY Nuclear Data Processing System was used to extract the relevant Evaluated Nuclear Data File (ENDF) information needed to create cross-section and covariance libraries. These libraries, a 100-group input spectrum generated using the Monte Carlo N-Particle transport code, and the activation foil data was analyzed using a generalized least-squares approach via the STAYSL PNNL code. The results of this study culminate in ensuring accurate neutron flux spectra are used in further research conducted at the EPNT and BP 1-5 reactor locations

Download or read book Neutron Beam Characterization at the Finnish BNCT Facility Measurements and Calculations written by T. Serén and published by . This book was released on 2001 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Boron Neutron Capture Therapy (BNCT) treatment facility with an epithermal neutron beam has been successfully completed at the Finnish FiR 1 TRIGA reactor at VTT, Espoo. The clinical trials on human patients were started in May 1999. The beam utilizes a specially developed moderator material FLUENTALTM. Extensive measurements and calculations have been carried out to characterize the neutron and gamma fields, both in the "free beam" and in tissue substitute phantoms. Despite the fairly low reactor power (250 kW) an epithermal fluence rate of 1.06 x 109 n cm-2 s-1 is achieved at the beam exit aperture with low fast-neutron contamination. The beam has been modeled in detail using the DORT transport code with the BUGLE-80 library. The neutron spectrum has been adjusted with the LSL-M2 code based on multiple-foil activation. Similar calculations and measurements have been performed by the Finnish BNCT team at the BMRR facility for direct comparison.

Download or read book Design and Characterization of a Facility for Fast Neutron Irradiation of Semiconductors at Penn State written by B. Petrovic and published by . This book was released on 2001 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the design and characterization of a fast neutron irradiation facility (FNI) at the Penn State Breazeale Reactor. The facility was designed to provide a hard neutron spectrum with a minimum of contamination by thermal neutrons and gamma rays, and to accommodate semiconductor wafers of up to 8 inches (~20 cm) in diameter. The design was effected through two-step Monte Carlo simulations that included (i) core criticality simulations, and (ii) FNI shielding analysis. A rectangular FNI shape was selected to improve the neutronic coupling between the FNI and the core. Analysis was performed to determine an optimum combination of materials and their dimensions. The FNI was constructed and it has been in use for about two years now. A set of activation foils was irradiated to obtain the FNI neutron spectrum andevaluate spatial flux distribution. The neutron spectrum was unfolded using the SAND-II code. Good agreement was observed between the calculated and measured data.

Download or read book Design Construction and Demonstration of a Neutron Beamline and a Neutron Imaging Facility at a Mark I TRIGA Reactor written by Aaron E. Craft and published by . This book was released on 2013 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design of an In core Fission Spectrum Neutron Irradiation Facility with Pneumatic Sample Transfer at a Research Reactor written by Brandon Alexander De Luna and published by . This book was released on 2019 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis was to provide instruction on the design, optimization and construction of a fast neutron irradiation facility with pneumatic sample transfer at the Nuclear Engineering Teaching Lab (NETL) reactor core. This facility will be used for fast neutron activation analysis and fast neutron fission in uranium and plutonium samples. Various materials and geometric designs were researched and modeled in Monte Carlo Neutral Particle (MCNP) code for the filtration of thermal neutrons from the NETL reactor core. The approach to these models were described as well as the subsequent processes in yielding the finalized design. The model geometry was recreated in SCALE to provide estimations for expected fission product activities. The design that was built was based off a layered cylindrical format that was placed inside a modified 3-element (EL) container. This container was created to fit into the 3-EL irradiation position of the core. The design balances the need to maintain high total neutron flux with the careful shaping of a neutron spectrum to be as close to the Watt fission spectrum as possible. The models indicated that the thermal+epithermal neutron flux was reduced by five orders of magnitude while leaving the fast neutron flux virtually untouched. That value was tallied after the reactor core flux is shaped by the neutron absorbing materials. The fast:(thermal+epithermal) flux ratio should exceed 100:1 with an integrated fast flux value (defined > 0.001 MeV) of at least 7.8 x 1011 n cm−2 s−1. The calculated activity from the irradiation of 10 mg Pu via SCALE was determined to be 94.97 MBq

Download or read book Clinical Characterization of Horizontal Fast Neutron Beam for Cancer Treatment at UCLA Neutron Therapy Facility written by Steve Pai-hsun Lee and published by . This book was released on 1986 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermal Neutron Beam Design for Triga Reactor at Berkeley Campus written by and published by . This book was released on 1967 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Beam Characterization at the Neutron Radiography Facility NRAD written by and published by . This book was released on 1992 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ongoing project to characterize the neutron beams at the Neutron Radiography Reactor (NRAD) is described in this paper. The effort has consisted of computer modelling with three dimensional diffusion theory to obtain a trail spectrum, foil activation measurements, and the use of SAND-II unfolding code. It was expected and found that diffusion theory will underpredict the fast flux. However, it is claimed that precise characterization of the entire spectrum is not necessary for comparisons among neutron radiography facilities; rather, the use of simple fast neutron indicators should be adequate. A specific example used at NRAD is the U-235/U-238 fission reaction rate ratio. A ratio such as this could be used in the same manner as the classic gold cadmium ratio for interfacility comparisons with regard to fast neutrons. 5 refs.

Download or read book Measurements at Beam Hole HB 2 of the Oak Ridge Research Reactor for South Facility Movable Shield Design Study written by and published by . This book was released on 1961 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Construction and Calibration of a Fast Neutron Spectrum Generator written by Kenneth Dwight Dobbin and published by . This book was released on 1974 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: A standard fast reactor spectrum can be created by the partial moderation of the U-235 fission spectrum in an air cavity. Spherical natural uranium shells are driven by thermal neutrons from a thermal column. The uranium is placed at the center of a spherical graphite hohlraum to reduce the anisotropic effect of a planar source of thermal neutrons. The Oregon State University (OSU) fast neutron spectrum facility design employs this method which is being used by Albert Fabry in Mol, Belgium and the NISUS assembly in London, United Kingdom, to create a fast neutron spectrum. The OSU facility uses the ther malizing column of a TRIGA Mark II reactor for a thermal neutron source. The mechanical design is presented showing the location of the facility, the aluminum container and internals, and the transport assembly. Two computer codes are introduced in the nuclear design. SLAB is a first approximation diffusion theory code which justifies the use of one foot of graphite backed with water in place of "infinite graphite." FASTSPEC is a diffusion theory approximation code in spherical geometry which shows that the design will produce a spectrum characteristic of a fast reactor. Phase I operation is a mechanical test, health physics evaluation, and a thermal neutron calibration of the facility with a thermal neutron absorber in place of the uranium. The data for phase I is included. Phase II operation will be the insertion of an uranium driver shell and the calibration of the fast spectrum. Only phase I is complete at this time.