Cosmic rauon induced neutrons are a major source of background for low count rate experiments like neutrino oscillation or dark matter searches. Especially at shallow sites these neutrons are the limiting factor for the ultimate sensitivity of the measurement. Measurements of the neutron rate and counter measures including active veto and passive shielding ...
NASA Astrophysics Data System (ADS)
Survey / coordinate with potential dosimetry experiment collaborators. " Develop shielding / dosimetry space experiment ...
NASA Website
Shielded special nuclear material (SNM) is very difficult to detect and new technologies are needed to clear alarms and verify the presence of SNM. High-energy photons and neutrons can be used to actively interrogate for heavily shielded SNM, such as highly enriched uranium (HEU), since neutrons can penetrate gamma-ray shielding and ...
Energy Citations Database
The space radiation environment is comprised of a complex and variable mix of high energy charged particles, gamma rays and other exotic species. Elements of this radiation field may also interact with intervening matter (such as a spaceship wall) and create secondary radiation particles such as neutrons. Some of the components of the space radiation environment are highly penetrating and can ...
Shielding benchmark problems were prepared by the Working Group of Assessment of Shielding Experiments in the Research Comittee on Shielding Design of the Atomic Energy Society of Japan, and compiled by the Shielding Laboratory of Japan Atomic Energy Rese...
National Technical Information Service (NTIS)
Radiation risk management for human space missions depends on accurate modeling of high-energy heavy ion transport in matter. The process of nuclear fragmentation can play a key role in reducing both the physical dose and the biological effectiveness of the radiation encountered in deep space. Hydrogenous materials and light elements are expected to be more effective shields ...
... SPACE ENVIRONMENTS, SHIELDING, NUCLEAR RADIATION, COSMIC RAYS ... NUCLEAR RADIATION SHIELD, PROTECTION & ...
DTIC Science & Technology
the international high-energy physics community, the FLUKA particle transport ... accelerator-based elementary particle physics experiments. ...
accelerator-based experiments have been the primary source of new discoveries in particle physics. The Large Hadron Collider is the world�s more powerful accelerator,...
Science.gov Websites
The space radiation environment poses risks to astronaut health from a diverse set of sources, ranging from low-energy protons and electrons to highly-charged, high-energy atomic nuclei and their associated fragmentation products, including neutrons. The low-energy protons and electrons are the source of most of the radiation dose to Shuttle and ISS crews, while the more energetic particles that ...
DOE Information Bridge
Although accelerator based experiments for undergraduates are often considered only for junior or senior physics majors, introductory students can also benefit from them. Rutherford backscattering and a {sup 12}C(p,p){sup 12}C elastic scattering resonance can be presented in ways that are well-suited for students who have taken only an ...
The space radiation environment presents a potential hazard to the humans, electronics and materials that are exposed to it. Particle accelerator facilities such as the NASA Space Ra-diation Laboratory (NSRL) and Loma Linda University Medical Center (LLUMC) provide particle radiation of specie and energy within the range of that found in the space radiation environment. ...
Accelerator-based atomic physics experiments at Brookhaven presently use heavy-ion beams from the Dual MP Tandem Van de Graaff Accelerator Facility for atomic physics experiments of several types. Work is presently in progress to develop experiments which will use the intense photon beams which will be available in ...
Sep 19, 2005 ... Both the dosimetry issue and the spot shielding issue are critical to use of COTS microelectronics in space system design. ...
After a brief review of the current neutrino oscillation status, we present neutrino oscillation results for recent and current accelerator-based neutrino experiments including K2K, MiniBooNE and MINOS experiments. We also foreshadow to prospects and status of future various accelerator-based neutrino physics ...
The Idaho National Laboratory, along with Los Alamos National Laboratory and the Idaho State University's Idaho Accelerator Center, are developing electron accelerator-based, photonuclear inspection technologies for the detection of shielded nuclear material within air-, rail-, and especially, maritime-cargo transportation containers. This paper describes ...
Radiation assessment and protection in space is the first step in planning future missions to the Moon and Mars, where mission and number of space travelers will increase and the protection of the geomagnetic shielding against the cosmic radiation will be absent. In this framework, the shielding effectiveness of two flexible materials, Kevlar and Nextel, ...
PubMed
In this study, a series of engineering benchmark experiments have been performed on the critical issues of shielding designs for DT fusion reactors. Based on the experiments, calculational accuracy of shielding design methods used in the ITER conceptual d...
An integral experiment has been performed for verification of radiation transport methods used in the design of the exit shield for the proposed gas-cooled fast breeder reactor demonstration plant. The experiment was conducted at the ORNL Tower Shielding ...
The results of the analysis of the GCFR Grid-Plate Shield Design Confirmation Experiment are presented. The experiment, performed at the ORNL Tower Shielding Facility, was designed to test the adequacy of methods and data used in the analysis of the GCFR ...
, where no shielding was installed, the dose rates in period 3 are not consistently higher shielding p #12;`#14; #5; cm). On the proton side, where shielding was installed, the dose rates in period 3 are systematically experiment. Using data from two different exposures we measure the effect of additional ...
E-print Network
Design analyses and tradeoff studies for the bulk shield of the Tokamak Fusion Core Experiment (TFCX) were performed. Several shielding options were considered to lower the capital cost of the shielding system. Optimization analyses were carried out to re...
The importance of shielding temperature sensors from solar radiation is understood, but there is a lack of prescriptive advice for plant scientists to build inexpensive, effective shields for replicated field experiments. Using general physical principles that govern radiation shielding, a number of...
Technology Transfer Automated Retrieval System (TEKTRAN)
LIPS 3 is a member of the Living Plume Shield series of spacecraft. In each LIPS project, the plume shield, a simple sheet metal cone, was structurally stiffened, and an active satellite was then built around it. The original purpose of the plume shield w...
The tokamak radiation shielding includes the neutron and gamma shielding around the torus and penetrations required to (1) limit activation of components outside the shield to levels that permit hands-on maintenance and (2) limit the nuclear heating of th...
The authors have studied the optimal machine shield system through experiments on a 20kVa superconducting generator. The first experiment is carried out on a fully iron-less aluminum-shield machine which has only an aluminum eddy current machine shield in the stator. The second ...
A Molten-Salt Reactor Program for power applications was initiated at the Oak Ridge National Laboratory in 1956. In 1965 the Molten Salt Reactor Experiment (MSRE) went critical and was successfully operated for several years. Operation of the MSRE reveale...
Atomic Physics research with beams from accelerators has continued to expand and the number of papers and articles at meetings and in journals reflects a steadily increasing interest and an increasing support from various funding agencies. An attempt will...
Shielding is the only practical countermeasure for the exposure to cosmic radiation during space travel. It is well known that light, hydrogenated materials, such as water and polyethylene, provide the best shielding against space radiation. Kevlar and Nextel are two materials of great interest for spacecraft shielding because of their ...
The integral test of neutron cross sections for major shielding materials in JENDL-3 has been performed by analyzing various shielding benchmark experiments. For the fission-like neutron source problem, the following experiments are analyzed: (1) ORNL Bro...
The analysis of iron shield bench-mark experiments was made to study the common characteristics of the experiments. The bench-mark experiments analyzed were those made at Karlsruhe, Livermore, Rensselaer, Protens, Winfrith, Oak Ridge and Harmonie. The fir...
... Whipple bumper shields, Numerical simulation of experiment, Hypervelocity impact, Smoothed particle hydrocode, CTH Hydrocode. ...
A new type of ether drift experiment searches for anomalous torques on a permanent magnet. A torsion
NASA Technical Reports Server (NTRS)
... out scale-model shielding studies and applying the results of these studies to full-scale structures indicate that scale-model experiments can be ...
americium-beryllium spherical neutron source surrounded by a .... the shield materials tungFten and urcaium-233 (ref 23 and 24). ...
This experiment was performed in the Water Shield Testbed (WST) at the NASA Marshall Space ... The thermosyphon evaporators are placed in the water -2.5 cm ...
Jul 5, 2011 ... Detector groupings were as follows: (1) a three-element (A, B, and C) differentially shielded telescope, with tube C shielded ...
Comments and data are included on FFTF radiation sources, dose rate criteria, shield materials, design methods, and startup testing. (ERA citation 01:019306)
... It has also been tested for a special concrete that has been used in many shielding experiments at the ORNL Tower Shielding Facility, as well as for ...
Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In ...
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 ...
The tokamak radiation shielding includes the neutron and gamma shielding around the torus and penetrations required to (1) limit activation of components outside the shield to levels that permit hands-on maintenance and (2) limit the nuclear heating of the superconducting coils and cold structure. The primary design drivers are space, ...
High strength fiber is a potential material for shielding from a viewpoint of strength, lightweight and flexibility. We developed a single bumper shield based on Vectran fibers, that stopped a polycarbonate projectile with 14 mm in diameter, 1 g in weight and 6.45 km/s in velocity. The thickness of this shield was 7 mm. As compared ...
The nEDM Experiment at the SNS requires an overall magnetic shielding factor of order 10^5 to attenuate external background magnetic fields. At present, the shielding design includes an external (room-temperature) multi-layer ?-metal magnetic shield, a cryogenic (4 Kelvin) Pb superconducting ...
A method for shielding of the thymus in mice during external irradiation is described. The results of the experiments indicate that thymic shielding during roentgen irradiation promotes the regeneration of extrathymic lymphoid tissues and the recovery of the number of lymphoid cells in the peripheral blood. (auth)
TEST (Tank Evaluation SysTem) is a research project utilizing neutron interrogation techniques to analyze the content of nuclear poisons and moderators in tank shielding. TEST experiments were performed on an experimental SAT (Shielded Annular Tank) at th...
The survivability and performance of the debris shields on the National Ignition Facility (NIF) are a key factor for the successful conduct and affordable operation of the facility. The improvements required over Nova debris shields are described. Estimat...
The current-voltage characteristic of a charged probe in the wake of a shielding disk is calculated using the POLAR code. The current-voltage curves are parameterized with respect to the tilt angle of the shielding disk. Estimates of the magnitude of prob...
Military-media relations in Operation Desert Shield is analyzed by comparing how the media has been handled in recent military operations to Desert Shield. Past operations are reviewed to discern if the military is learning from these experiences so that ...
A cooperative shielding research program between the US Department of Energy and Japan's Power Reactor and Nuclear Fuel Development Corporation has been initiated. The program includes six specific shielding integral experiments to be performed at the Oak...
We conducted nine experiments to investigate the fire endurance of a borated polyethylene shielding material to be used in the Engineering Demonstration System. Several chemistry tests were also done. The shielding material was found to melt at 93.5 deg C...
Experiments on a scale model of an advanced unconventional subsonic transport concept, the Blended Wing Body (BWB), have demonstrated significant shielding of inlet-radiated noise. A computational model of the shielding mechanism has been developed using ...
In an effort to develop a theory for shielding against lightning in winter, model experiments are made for cases where transmission lines or tall structures under a uniform thundercloud are to be shielded against lightning by means of a lightning conducto...
An analytical method of attenuation calculation of shielding materials is discussed. Examples of shielding calculations with buildup factor (gamma) and three-group method (neutron) for a research reactor are given. The use of concrete materials as shieldi...
The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating ...
The literature on shielding experiment and calculation of high energy particles above 20 MeV has been surveyed. The survey covers thirteen journals, from 1965 up to 1989. For each paper, applicable information is listed on type and energy of the projectile, the accelerator used, composition and thickness of the target and shielding ...
An analysis is presented of the experiments performed at the ORNL Tower Shielding Facility during the months of September through Deeember, 1956 in which 2 pi covers were placed on the reactor shield and crew shield of a shield system. The analysis covers radiation penetrating the ...
An integral experiment has been designed for the verification of radiation transport methods and nuclear data used for the design of the radial shield for the proposed 300 MW(e) gas-cooled fast breeder reactor (GCFR). The scope of the experiment was chose...
During the past contract year important new results have been obtained in the surface shielding experiment and in the polarized He(3) experiment. In this period the temperature transition in the anomalous surface shielding effect was discovered and invest...
Verification of methods for analysis of radiation-transport (shielding) problems in Liquid-Metal Fast Breeder Reactors has required a series of experiments that can be classified as benchmark, parametric, or design-confirmation experiments. These experiments, performed at the Oak Ridge Tower ...
The Idaho National Laboratory, along with Los Alamos National Laboratory and the Idaho State University�s Idaho Accelerator Center, are developing electron accelerator-based, photonuclear inspection technologies for the detection of shielded nuclear material within air-, rail-, and especially, maritime-cargo transportation containers. This paper ...
A pseudo-line source has been realized by using an accelerator based D-T point neutron source. The pseudo-line source is obtained by time averaging of continuously moving point source or by superposition of finely distributed point sources. The line sourc...
Experimental data taken with 2 pi shields between August and December 1958 are presented in graphs. The experiments were carried out to determine conditions necessary to make meaningful and useful measurements in and around a reactor crew shield system. The shields are described and diagrams given. ...
The thickness of the lateral, bottom, and top shields of ECO for the nominal power of 1 kw is given. For reduced power, three bottom shields are proposed. The penetrations in the various shields are verified, as well as the activity of the cooling air. (auth)
Shielding and containment criteria for the Transuranium Facility obtained by calculations and experiments are given. The shield evaluation studies (for cell walls, cell windows, and fission source carriers) utilized experiments at the ORNL Lid Tank Shielding Facility and IBM-7090 ...
An integral experiment has been performed for verification of radiation transport methods and nuclear data used in the design of the radial shield for the proposed gas-cooled fast breeder reactor demonstration plant. The experiment was conducted at the ORNL Tower Shielding Facility and consisted of integral and ...
In the early 1950's, the concept of the unit shield for the nuclear powered aircraft reactor changed to one of the divided shield concept where the reactor and crew compartment shared the shielding load. Design calculations for the divided shield were being made based on data obtained in studies for the, ...
In the early 1950`s, the concept of the unit shield for the nuclear powered aircraft reactor changed to one of the divided shield concept where the reactor and crew compartment shared the shielding load. Design calculations for the divided shield were being made based on data obtained in studies for the, unit ...
Experiments are being developed at the Triangle Universities Nuclear Laboratory to offer undergraduate physics majors laboratory experiences in the atmosphere of a frontier accelerator facility. These experiments differ from projects done by Undergraduate Research Assistants in that they are designed specifically for integration into ...
An integral shielding experiment has been designed to investigate neutron penetration through benchmark and representative mockups of the radial shield designs for advanced sodium-cooled reactor concepts. The experiment will be performed in FY 1986 at the ORNL Tower Shielding Facility to study ...
Neutrino oscillations were first discovered by experiments looking at neutrinos coming from extra-terrestrial sources, namely the sun and the atmosphere, but we will be depending on earth-based sources to take many of the next steps in this field. This article describes what has been learned so far from accelerator-based neutrino oscillation ...
The SNS is an accelerator based neutron source in Oak Ridge, Tennessee. This unique facility provides the most intense pulsed neutron beams in the world, which are produced by bombarding a mercury target with energetic protons from a large accelerator complex. A high intense pulsed proton beam traveling through the RTBT (Ring to Target Beam Transport) line ...
An exploratory investigation was made to determine the feasibility of applying the partial shield concept to airplane servicing. The objective of this experiment was to determine the extent of the development effort which would be needed to implement the partial shield concept and to indicate major problem areas. In this ...
During the period between 1975 and 1980 a series of experiments was performed at the ORNL Tower Shielding Facility in support of the shield design for a 300-MW(e) Gas Cooled Fast Breeder Demonstration Plant. This report reviews the experiments and calculations, which included studies of: (1) neutron streaming in ...
The shielding was designed to comply with the ML-1 performance specifications that stipulated that the biological shield should attenuate the radiation to certain specified levels within 24 hours after the reactor was shut down from full power operation. Additional shielding was to be provided as possible within the size and ...
The MINER?A experiment at Fermilab will use a fully-active scintillator based fine grained neutrino detector and the high rate NuMI neutrino beam. MINER?A will measure low energy neutrino interaction properties and cross sections to a new level of precision. These measurements will be critical input to present and future accelerator-based neutrino ...
A pilot accelerator-based source of epithermal neutrons, which is intended for wide application in clinics for boron neutron capture therapy, has been constructed at the Budker Institute of Nuclear Physics (Novosibirsk). A stationary proton beam has been obtained and near-threshold neutron generation regime has been realized. Results of the first ...
The Naval Academy Tandem Accelerator Laboratory is dedicated to providing educational experiences for undergraduates. Students gain experience in accelerator operations, detector and data acquisition systems, nuclear structure and reaction mechanisms, and materials analysis techniques. Suggestions for managing the laboratory sessions are given. Examples ...
This report provides information concerning: the experiment facility; experiment assembly; instrumentation and controls; materials; radioactivity; shielding; thermodynamics; estimated or measured reactivity effects; procedures; hazards; and quality assurance. (JDB)
centering clamp 4. He Pressure Vessel (Inconel 625) 5. Thermal Shield (Lead/glass composite) 6. Shield to over-compression by close out welds Operationally Experiment times ~ 2 hrs Rapid recool cycle developed
In the framework of the European Technology Program for NET/ITER, ENEA (Italian Agency for New Technologies, Energy and Environment) - Frascati and CEA (Commissariat a L'Energie Atomique) - Cadarache collaborated on a Bulk Shield Benchmark Experiment usin...
A new method for analyzing data from structure shielding experiments was developed. It involves the separate treatment of the direct and skyshine components of the gamma-ray dose rate in a structure from a source field on the ground outside the structure....
A comparison is made between experiment and theory for the calculation of shielding by a structure against fallout radiation. Experimental results for exposure penetrating a roof slab, and for reduction factor, are found to agree with moments theory calcu...
Shield measurements and four cycles of operating experience have shown the design and construction of radiation shields for the Fast Flux Test Facility (FFTF) reactor and plant to be satisfactory. A number of minor shield deficiencies were found and corrected. Most of these were associated with interfaces between ...
... Title : Intratheater Ground Transportation Operations During Desert Shield and Desert Storm: A Personal Experience Monograph. ...
of iron nanoparticles in the fibers. These fibers are under consideration for use in lighweight. EMI shielding. Wedesigned experiments on electrochromic ...
These experiments and the ensuing analysis, in combinations with countless hydrocode simulations, have contributed to the development of shield ballistic limit ...
With the advent of a new generation of high-energy and high-intensity proton accelerators such as the one being built at the National Accelerator Laboratory and the one proposed by CERN, the problem of shielding external proton targets, the secondary beams produced from these targets, and even the secondary targets in the experimental areas becomes quite a massive and ...
During the period between 1975 and 1980 a series of experiments was performed at the ORNL Tower Shielding Facility in support of the shield design for a 300-MW(e) Gas Cooled Fast Breeder Demonstration Plant. This report reviews the experiments and calcula...
