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Caffrey, A. J.

Publications and source records attributed to Caffrey, A. J..

8 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

OSIRIS Validation and Verification Report

The On-Site Inspection RadioIsotopic Spectroscopy (OSIRIS) system is a gamma-ray spectroscopy instrument for on-site inspections conducted under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The OSIRIS software filters spectral analysis data, revealing information to users on only 17 CTBT-relevant fission-product isotopes. In this report, we review the CTBT requirements for on-site inspection radionuclide identifiers, plus additional requirements imposed by the design team. Then a series of validation tests conducted during OSIRIS development are described. The validation tests were designed to gauge if the nascent OSIRIS system met those requirements. We conclude with a set of recommended verification tests to ensure that newly-manufactured OSIRIS systems also will meet the requirements.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

On-Site Inspection RadioIsotopic Spectroscopy (Osiris) System-Integration and Field-Testing Report

We have designed a system for the acquisition and analysis of high-resolution gamma-ray spectra during on-site inspections under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The On-Site Inspection RadioIsotopic Spectroscopy—OSIRIS —gamma-ray spectrometer is a mechanically-cooled, battery-powered ORTEC IDM-200V, chosen to avoid the need for liquid nitrogen during on-site inspections. The spectrometer is controlled and the spectral data analyzed by a Panasonic Toughbook notebook computer. Spectral data analysis is similar to that performed by traditional gamma-ray spectrometers, except the OSIRIS gamma-ray spectral data are filtered to display only radioisotopic information relevant to CTBT on-site inspections, for example, the fission-product isotope Zr-95 and its daughter isotope Nb-95. The OSIRIS software assists the user during operation with software checklists for startup and shutdown, and menu-selected display windows during energy calibration and data acquisition. OSIRIS can be operated in either sample-counting mode or the in-situ mode. In this report, the extensive system-integration tests of the OSIRIS system carried out in 2015-2017 are described, including tests at Idaho National Laboratory, at the Nevada National Security Site (formerly, the Nevada Test Site), and at Pacific Northwest National Laboratory in Richland, Washington. We also note recent software enhancements and the steps to our successful commercialization of OSIRIS.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Calorimeter development for the SuperNEMO double beta decay experiment

SuperNEMO is a double-β decay experiment, which will employ the successful tracker–calorimeter technique used in the recently completed NEMO-3 experiment. SuperNEMO will implement 100 kg of double-β decay isotope, reaching a sensitivity to the neutrinoless double-β decay (Ovββ) half-life of the order of 10 26 yr, corresponding to a Majorana neutrino mass of 50–100 meV. One of the main goals and challenges of the SuperNEMO detector development programme has been to reach a calorimeter energy resolution, ΔE/E, around 3%/ $\sqrt{E9MeV)}$σ, or 7% $\sqrt{E9MeV)}$ FWHM (full width at half maximum), using a calorimeter composed of large volume plastic scintillator blocks coupled to photomultiplier tubes. Here, we describe the R&D programme and the final design of the SuperNEMO calorimeter that has met this challenging goal.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Measurement of the 2 ν β β decay half-life and search for the 0 ν β β decay of Cd 116 with the NEMO-3 detector

The NEMO-3 experiment measured the half-life of the 2νββ decay and searched for the 0νββ decay of 116 Cd. Using 410 g of 116 Cd installed in the detector with an exposure of 5.26 y, (4968±74) events corresponding to the 2νββ decay of 116 Cd to the ground state of 116 Sn have been observed with a signal to background ratio of about 12. The half-life of the 2νββ decay has been measured to be T 2ν 1/2 = [2.74 ± 0.04(stat) ± 0.18(syst)] × 10 19 y. No events have been observed above the expected background while searching for 0νββ decay. The corresponding limit on the half-life is determined to be T 0ν 1/2 ≥ 1.0 × 10 23 y at the 90% C.L. which corresponds to an upper limit on the effective Majorana neutrino mass of < m ν > ≤ 1.4–2.5 eV depending on the nuclear matrix elements considered. As a result, limits on other mechanisms generating 0νββ decay such as the exchange of R-parity violating supersymmetric particles, right-handed currents and majoron emission are also obtained.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2014

Search for neutrinoless double-beta decay of Mo 100 with the NEMO-3 detector

We report the results of a search for the neutrinoless double-ß decay (0?ßß ) of Mo 100 , using the NEMO-3 detector to reconstruct the full topology of the final state events. With an exposure of 34.7??kg·y , no evidence for the 0?ßß signal has been found, yielding a limit for the light Majorana neutrino mass mechanism of T 1/2 (0?ßß)>1.1×10 24 years (90% C.L.) once both statistical and systematic uncertainties are taken into account. Depending on the nuclear matrix elements this corresponds to an upper limit on the Majorana effective neutrino mass of ?m ? ?<0.3–0.9??eV (90% C.L.). Constraints on other lepton number violating mechanisms of 0?ßß decays are also given. Searching for high-energy double electron events in all suitable sources of the detector, no event in the energy region [3.2–10] MeV is observed for an exposure of 47??kg·y .

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2014

Investigation of Double Beta Decay of 100Mo to Excited States of 100Ru

Double beta decay of 100Mo to the excited states of daughter nuclei has been studied using a 600 cm3 low-background HPGe detector and an external source consisting of 2588 g of 97.5% enriched metallic 100Mo, which was formerly inside the NEMO-3 detector and used for the NEMO-3 measurements of 100Mo. The half-life for the two-neutrino double beta decay of 100Mo to the excited View the MathML source state in 100Ru is measured to be T1/2=[7.5±0.6(stat)±0.6(syst)]·1020 yr. For other (0?+2?) transitions to the View the MathML source, View the MathML source, View the MathML source, View the MathML source and View the MathML source levels in 100Ru, limits are obtained at the level of ~(0.25–1.1)·1022 yr.

100Mo↗