Engineering Papers⌕ Search

Engineering topics

Fast, James E

Publications and source records attributed to Fast, James E.

12 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

A shallow underground laboratory for low-background radiation measurements and materials development

Pacific Northwest National Laboratory recently commissioned a new shallow underground laboratory, located at a depth of approximately 30 meters-water-equivalent. This new addition to the small class of radiation measurement laboratories located at modest underground depths houses the latest generation of custom-made, high-efficiency, low-background gamma-ray spectrometers and gas proportional counters. This paper describes the unique capabilities present in the shallow underground laboratory; these include large-scale ultra-pure materials production and a suite of radiation detection systems. Reported data characterize the degree of background reduction achieved through a combination of underground location, graded shielding, and rejection of cosmic-ray events. We conclude by presenting measurement targets and future opportunities.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2011

The Majorana Experiment

The Majorana collaboration is actively pursuing research and development aimed at a tonne-scale {sup 76}Ge neutrinoless double-beta decay ({beta}{beta}(0{nu})-decay) experiment. The current, primary focus is the construction of the Majorana Demonstrator experiment, an R and D effort that will field approximately 40 kg of germanium detectors with mixed enrichment levels. This article provides a status update on the construction of the Demonstrator.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2011

CASCADES: An Ultra-Low-Background Germanium Crystal Array at Pacific Northwest National Laboratory

State-of-the-art treaty verification techniques, environmental surveillance, and physics experiments require increased sensitivity for detecting and quantifying radionuclides of interest. This can be accomplished with new detector designs that establish high detection efficiency and reduced instrument backgrounds. Current research is producing an intrinsic germanium (HPGe) array designed for high detection efficiency, ultra-low-background performance, and sensitive {gamma}--{gamma} coincidence detection. The system design is optimized to accommodate filter paper samples, e.g. samples collected by the Radionuclide Aerosol Sampler/Analyzer. The system will provide high sensitivity for weak collections on atmospheric filter samples (e.g.<10{sup 5} fissions) as well as offering the potential to gather additional information from higher activity filters using gamma cascade coincidence detection. The first of two HPGe crystal arrays in ultra-low-background vacuum cryostats has been assembled, with the second in progress. Traditional methods for constructing ultra-low-background detectors were followed, including use of materials known to be low in radioactive contaminants, use of ultra-pure reagents, and clean room assembly. The cryostat is constructed mainly from copper electroformed into near-final geometry at Pacific Northwest National Laboratory. Details of the detector assembly and initial background and spectroscopic measurement results are presented; also a description of the custom analysis package used by this project is given.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2011

Belle II Detector: status and proposed US contributions

Conference proceedings for the 2012 American Physical Society, Division of Particles and Fields (DPF2012) conference. Paper is on the US contibutions to the Belle II detector upgrade. High precision flavor physics measurements are an essential complement to the direct searches for new physics at the LHC. Such measurements will be performed using the upgraded Belle II detector and upgraded KEKB accelerator. The status of the Belle II detector and proposed role of the US Belle II collaborators are presented in this article. The B factory experiments, Belle at the KEKB collider at KEK and BaBar at the PEP II collider at SLAC, were built to measure the large mixing-induced CP violation in the B0 system predicted by the theory of Kobayashi and Maskawa. The successful confirmation of the prediction led to the Nobel Prize for both theorists. The B factories were built to answer the question Is the CKM description in the Standard Model correct? Most B factory results are in good agreement with the expectations from the Standard Model (SM) and confirm the CKM structure of quark mixing and CP violation, but some measurements show tensions with the SM prediction. The Super B factories will address the question In what way is the Standard Model wrong? Much larger datasets are needed for high-precision measurements to search for significant deviations from the SM which are expected to exist. The SuperKEKB and Belle II detector are being constructed to perform these high precision studies with a dataset 50ab{sup -1}. The SuperKEKB accelerator will operate at an instantaneous luminosity of 8 x 10{sup 35}cm{sup -2}s{sup -1}, a factor of 40 times higher than the luminosity of the KEKB accelerator at the end of the Belle physics program. The increased luminosity will derive primarily from shrinking the beam size at the interaction point (nano beams) utilizing new final focus quadrapole magnets in combination with a factor of 2 increase in beam currents. To counteract the increase in the beam-beam parameter due to the reduced beta functions, the beam emittance must also be reduced; this will be achieved with a new electron source and a new damping ring.

43 PARTICLE ACCELERATORS↗
DOE OSTI2011

Design Considerations for Large Mass Ultra-Low Background Experiments

Summary The objective of this document is to present the designers of the next generation of large-mass, ultra-low background experiments with lessons learned and design strategies from previous experimental work. Design issues divided by topic into mechanical, thermal and electrical requirements are addressed. Large mass low-background experiments have been recognized by the scientific community as appropriate tools to aid in the refinement of the standard model. The design of these experiments is very costly and a rigorous engineering review is required for their success. The extreme conditions that the components of the experiment must withstand (heavy shielding, vacuum/pressure and temperature gradients), in combination with unprecedented noise levels, necessitate engineering guidance to support quality construction and safe operating conditions. Physical properties and analytical results of typical construction materials are presented. Design considerations for achieving ultra-low-noise data acquisition systems are addressed. Five large-mass, low-background conceptual designs for the one-tonne scale germanium experiment are proposed and analyzed. The result is a series of recommendations for future experiments engineering and for the Majorana simulation task group to evaluate the different design approaches.

1TGe One-tonne 76Ge neutrinoless double beta-decay↗
DOE OSTI2011

Majorana One-Tonne Cryostat Cooling Conceptual Feasibility Study Rev 1

This report evaluates the conceptual plans for a cryostat cooling design for the MAJORANA DEMONSTRATOR (MJD) one-tonne (S4) experiment. This document is based upon previous design work and experimental results used to evaluate the current MJD thermal design. A feasibility study of a cooling system for S4 based on the MJD thermosiphon experiment is presented. The one-tonne experiment will be a scaled up version of the MJD. There will be many cryostats in the S4 experiment. In this document a cryostat with up to 19 strings of germanium crystals is analyzed. Aside from an extra outer ring of crystals, the geometry of the cryostat for S4 is very similar to that for the MJD thermosiphon experiment. The materials used in the fabrication of both of these ultra-low background experiments will be underground-electroformed copper. The current MJD uses a two-phase liquid-gas cooling system to provide constant operating temperature. This document presents a theoretical investigation of a cooling system for the S4 experiment and evaluates the heat transfer performance requirements for such a system.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2011

Majorana One-Tonne Cryostat Cooling Conceptual Feasibility Study

This report evaluates the conceptual plans for a one-tonne (S4) cryostat cooling design. This document is based upon previous design work and experimental results used to evaluate the current MAJORANA DEMONSTRATOR (MJD) thermal design. A feasibility study of a cooling system for S4 based on the MJD thermosyphon experiment is presented. The one-tonne experiment will be a scaled up version of the MJD. There will be many cryostats for the S4 experiment. In this document a cryostat with up to 19 strings of Germanium crystals is analyzed. Aside from an extra outer ring of crystals, the geometry of both systems’ cryostats is very similar. The materials used in the fabrication of both ultra-low background experiments will be underground electroformed copper. The current MJD uses a two-phase liquid-gas cooling system to ensure constant operating temperature. This document presents a theoretical investigation of a cooling system for the S4 experiment and evaluates the heat transfer performance requirements for such a system.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

Search for an Annual Modulation in a p-Type Point Contact Germanium Dark Matter Detector

Fifteen months of cumulative CoGeNT data are examined for indications of an annual modulation, a predicted signature of weakly interacting massive particle (WIMP) interactions. Presently available data support the presence of a modulated component of unknown origin, with parameters prima facie compatible with a galactic halo composed of light-mass WIMPs. Unoptimized estimators yield a statistical significance for a modulation of {approx}2.8{sigma}, limited by the short exposure.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2010

Majorana Thermosyphon Prototype Experimental Results

Objective The Majorana demonstrator will operate at liquid Nitrogen temperatures to ensure optimal spectrometric performance of its High Purity Germanium (HPGe) detector modules. In order to transfer the heat load of the detector module, the Majorana demonstrator requires a cooling system that will maintain a stable liquid nitrogen temperature. This cooling system is required to transport the heat from the detector chamber outside the shield. One approach is to use the two phase liquid-gas equilibrium to ensure constant temperature. This cooling technique is used in a thermosyphon. The thermosyphon can be designed so the vaporization/condensing process transfers heat through the shield while maintaining a stable operating temperature. A prototype of such system has been built at PNNL. This document presents the experimental results of the prototype and evaluates the heat transfer performance of the system. The cool down time, temperature gradient in the thermosyphon, and heat transfer analysis are studied in this document with different heat load applied to the prototype.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2010

Majorana DUSEL R&D Final Report

This report summarizes the work performed at PNNL under the project Majorana Neutrinoless Double Beta Decay DUSEL R&D over the period of FY07-FY09.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

MARS Flight Engineering Status

The Multi-sensor Airborne Radiation Survey Flight Engineering project (MARS FE) has designed a high purity germanium (HPGe) crystal array for conducting a wide range of field measurements. In addition to the HPGe detector system, a platform-specific shock and vibration isolation system and environmental housing have been designed to support demonstration activities in a maritime environment on an Unmanned Surface Vehicle (USV). This report describes the status of the equipment as of the end of FY09.

33 ADVANCED PROPULSION SYSTEMS↗