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Ruz, J.

Publications and source records attributed to Ruz, J..

26 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Recent constraints on axion-photon and axion-electron coupling with the CAST experiment

The CERN Axion Solar Telescope (CAST) is a helioscope looking for axions arising from the solar core plasma and arriving to Earth. The experiment, located in Geneva (Switzerland) is able to follow the Sun during sunrise and sunset. Four x-ray detectors mounted on both ends of the magnet wait for photons from axion-to-photon conversion due to the Primakoff effect. Up to date, with the completion of Phases I and II, CAST has been looking for axions that could be produced in the Sun by both, hadronic and non-hadronic mechanisms.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

The next generation of axion helioscopes: The international axion observatory (IAXO)

The International Axion Observatory (IAXO) is a proposed 4 th -generation axion helioscope with the primary physics research goal to search for solar axions via their Primakoff conversion into photons of 1 – 10 keV energies in a strong magnetic field. IAXO will achieve a sensitivity to the axion-photon coupling g aγ down to a few ×10⁻¹² GeV⁻¹ for a wide range of axion masses up to ~ 0.25 eV. This is an improvement over the currently best (3 rd generation) axion helioscope, the CERN Axion Solar Telescope (CAST), of about 5 orders of magnitude in signal strength, corresponding to a factor ~ 20 in the axion photon coupling. IAXO’s sensitivity relies on the construction of a large superconducting 8-coil toroidal magnet of 20 m length optimized for axion research. Each of the eight 60 cm diameter magnet bores is equipped with x-ray optics focusing the signal photons into ~ 0.2 cm² spots that are imaged by very low background x-ray detectors. The magnet will be built into a structure with elevation and azimuth drives that will allow solar tracking for 12 hours each day. This contribution is a summary of our papers [1, 2, 3] and we refer to these for further details.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2014

A Time Projection Chamber for High Accuracy and Precision Fission Cross-Section Measurements

The fission Time Projection Chamber (fissionTPC) is a compact (15 cm diameter) two-chamber MICROMEGAS TPC designed to make precision cross-section measurements of neutron-induced fission. The actinide targets are placed on the central cathode and irradiated with a neutron beam that passes axially through the TPC inducing fission in the target. The 4p acceptance for fission fragments and complete charged particle track reconstruction are powerful features of the fissionTPC which will be used to measure fission cross-sections and examine the associated systematic errors. This paper provides a detailed description of the design requirements, the design solutions, and the initial performance of the fissionTPC.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2014

An Ethernet-based Data Acquisition System for the NIFFTE Time Projection Chamber

The goal of the NIFFTE Collaboration is to make neutron-induced fission cross section measurements to better than 1% total uncertainty, improving on the current ENDF values particularly for neutron energies belows 14 MeV. To that end, they are developing a time projection chamber (TPC) to directly measure the fission products from targets placed in a neutron beam at LANSCE.

Wood, L.↗
DOE OSTI2014

U and Pu Gamma-Ray Measurements of Spent Fuel Using a Gamma-Ray Mirror Band-Pass Filter

Abstract. We report on the use of grazing incidence gamma-ray mirrors to serve as a narrow band-pass filter for advanced non-destructive analysis (NDA) of spent nuclear fuel. The purpose of the mirrors is to limit the radiation reaching a HPGe detector to narrow spectral bands around characteristic emission lines from fissile isotopes in the fuel. This overcomes the normal rate issues when performing gamma-ray NDA measurements. In a proof-of-concept experiment, a set of simple flat gamma-ray mirrors were used to directly observe the atomic florescence lines from U and Pu from spent fuel pins with the detector located in a shirt-sleeve environment. The mirrors, consisting of highly polished silicon substrates deposited with WC/SiC multilayer coatings, successfully deflected the lines of interest while the intense primary radiation beam from the fuel was blocked by a lead beam stop. The gamma-ray multilayer coatings that make the mirrors work at the gamma-ray energies used here (~ 100 keV) have been experimentally tested at energies as high as 645 keV, indicating that direct observation of nuclear emission lines from 239Pu should be possible with an appropriately designed optic and shielding configuration.

Ziock, Klaus-Peter↗
DOE OSTI2013

The NIFFTE Project

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) is a double-sided Time Projection Chamber (TPC) with micromegas readout designed to measure the energy-dependent neutron-induced fission cross sections of the major and minor actinides with unprecedented accuracy. The NIFFTE project addresses the challenge of minimizing major sources of systematic uncertainties from previous fission chamber measurements such as: target and beam non-uniformities, misidentification of alpha and light charged particles as fission fragments, and uncertainties inherent to the reference standards used. In-beam tests of the NIFFTE TPC at the Los Alamos Neutron Science Center (LANSCE) started in 2010 and have continued in 2011, 2012 and 2013. An overview of the NIFFTE TPC status and performance at LANSCE will be presented.

gaseous detectors↗
DOE OSTI2013

Direct Measurement of U235 and Pu239 in Spent Fuel Rods with Gamma-Ray Mirrors

The amounts of fissile Pu and U in spent nuclear fuel are of primary concern to the safeguards community. In particular, there are issues when safeguards transitions from an item accountancy basis (such as fuel bundles) to a fissile material mass basis as occurs when spent fuel enters a reprocessing plant. Discrepancies occur because item accountancy requires estimating the content of fissile material using indirect techniques such as the fuel burn-up and item-level measurements of radiation emissions from fission by-products. Direct measurement of the fissile content by monitoring line emissions from fissile species themselves is impossible because the lines are much weaker than those emitted by shorter-lived isotopes in the fuel. The goal of this project is to develop a technique to directly measure these weaker lines despite the presence of overwhelming radiation from other isotopes. This is achieved by using gamma-ray mirrors as a narrow band-pass filter. The mirrors reflect only energies of interest toward a HPGe detector that is shielded from direct view of the spent fuel and its fierce emissions. This can significantly improve the reliability with which the mass of fissile material is tracked.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗