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Title: A Bayesian method to estimate the neutron response matrix of a single crystal CVD diamond detector

Abstract

Detectors made from artificial chemical vapor deposition (CVD) single crystal diamond are very promising candidates for applications where high resolution neutron spectrometry in very high neutron fluxes is required, for example in fusion research. We propose a Bayesian method to estimate the neutron response function of the detector for a continuous range of neutron energies (in our case, 10 MeV ≤ E{sub n} ≤ 16 MeV) based on a few measurements with quasi-monoenergetic neutrons. This method is needed because a complete set of measurements is not available and the alternative approach of using responses based on Monte Carlo calculations is not feasible. Our approach uses Bayesian signal-background separation techniques and radial basis function interpolation methods. We present the analysis of data measured at the PTB accelerator facility PIAF. The method is quite general and it can be applied to other particle detectors with similar characteristics.

Authors:
; ; ; ;  [1];  [2]
  1. Physikalisch-Technische Bundesanstalt, D-38116 Braunschweig (Germany)
  2. Paul Scherrer Institut, CH-5232 Villigen (Switzerland)
Publication Date:
OSTI Identifier:
22390865
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1641; Journal Issue: 1; Conference: MAXENT 2014: Conference on Bayesian Inference and Maximum Entropy Methods in Science and Engineering, Clos Luce, Amboise (France), 21-26 Sep 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ACCELERATOR FACILITIES; CHEMICAL VAPOR DEPOSITION; DATA ANALYSIS; DIAMONDS; DIELECTRIC TRACK DETECTORS; INTERPOLATION; MEV RANGE; MONOCRYSTALS; MONTE CARLO METHOD; NEUTRON DETECTION; NEUTRON DETECTORS; NEUTRON FLUX; NEUTRON SPECTROSCOPY; RESOLUTION; RESPONSE FUNCTIONS

Citation Formats

Reginatto, Marcel, Araque, Jorge Guerrero, Nolte, Ralf, Zbořil, Miroslav, Zimbal, Andreas, and Gagnon-Moisan, Francis. A Bayesian method to estimate the neutron response matrix of a single crystal CVD diamond detector. United States: N. p., 2015. Web. doi:10.1063/1.4905994.
Reginatto, Marcel, Araque, Jorge Guerrero, Nolte, Ralf, Zbořil, Miroslav, Zimbal, Andreas, & Gagnon-Moisan, Francis. A Bayesian method to estimate the neutron response matrix of a single crystal CVD diamond detector. United States. doi:10.1063/1.4905994.
Reginatto, Marcel, Araque, Jorge Guerrero, Nolte, Ralf, Zbořil, Miroslav, Zimbal, Andreas, and Gagnon-Moisan, Francis. 2015. "A Bayesian method to estimate the neutron response matrix of a single crystal CVD diamond detector". United States. doi:10.1063/1.4905994.
@article{osti_22390865,
title = {A Bayesian method to estimate the neutron response matrix of a single crystal CVD diamond detector},
author = {Reginatto, Marcel and Araque, Jorge Guerrero and Nolte, Ralf and Zbořil, Miroslav and Zimbal, Andreas and Gagnon-Moisan, Francis},
abstractNote = {Detectors made from artificial chemical vapor deposition (CVD) single crystal diamond are very promising candidates for applications where high resolution neutron spectrometry in very high neutron fluxes is required, for example in fusion research. We propose a Bayesian method to estimate the neutron response function of the detector for a continuous range of neutron energies (in our case, 10 MeV ≤ E{sub n} ≤ 16 MeV) based on a few measurements with quasi-monoenergetic neutrons. This method is needed because a complete set of measurements is not available and the alternative approach of using responses based on Monte Carlo calculations is not feasible. Our approach uses Bayesian signal-background separation techniques and radial basis function interpolation methods. We present the analysis of data measured at the PTB accelerator facility PIAF. The method is quite general and it can be applied to other particle detectors with similar characteristics.},
doi = {10.1063/1.4905994},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1641,
place = {United States},
year = 2015,
month = 1
}
  • A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes andmore » electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10{sup 7} cm/s and 1.0 ± 0.3 × 10{sup 7} cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5–1 keV and neutron yield of more than 10{sup 9} neutrons/shot.« less
  • A single crystal diamond detector was exposed to the quasi mono-energetic neutron fields in the energy range from 7 MeV to 20.5 MeV produced by the Van de Graaff neutron generator of the EC-JRC-IRMM. Pulse Height Spectra (PHS) of the neutron interaction with the diamond (carbon) were recorded in order to derive the experimental response function of this detector to neutrons in view of its use as a compact fast neutron spectrometer. Several peaks produced by outgoing charged particles produced when neutrons interact with carbon were identified using the reaction Q-values. The corresponding nuclear reactions, such as (n,{alpha}), (n,p), (n,d)more » for different excitation states were identified in the PHS. The analysis of the peaks allows the derivation of some neutron reaction cross sections in carbon. The results are presented in this paper together with the associated uncertainties.« less
  • We present a comparative characterization of the performance of a single-crystal and a polycrystalline diamond pixel-detector employing the standard CMS pixel readout chips. Measurements were carried out at the Fermilab Test Beam Facility, FTBF, using protons of momentum 120 GeV/c tracked by a high-resolution pixel telescope. Particular attention was directed to the study of the charge-collection, the charge-sharing among adjacent pixels and the achievable position resolution. The performance of the single-crystal detector was excellent and comparable to the best available silicon pixel-detectors. The measured average detection-efficiency was near unity, ε = 0.99860±0.00006, and the position-resolution for shared hits was aboutmore » 6 μm. On the other hand, the performance of the polycrystalline detector was hampered by its lower charge collection distance and the readout chip threshold. A new readout chip, capable of operating at much lower threshold (around 1 ke $-$), would be required to fully exploit the potential performance of the polycrystalline diamond pixel-detector.« less
  • The growth conditions and the detection properties of a homoepitaxial diamond film, deposited in Roma 'Tor Vergata' University Laboratories by microwave chemical vapor deposition on a high-pressure high-temperature single-crystal substrate are reported. An energy resolution as low as 1.1% was achieved when irradiating the device with 5.5 MeV {sup 241}Am {alpha}-particles. The dependence of the charge collection efficiency and the energy resolution on the applied voltage are reported as well. A clear saturation plateau was observed in both curves. Preliminary results with 14.8 MeV neutron irradiation are reported, showing a well separated {sup 12}C(n,{alpha}{sub 0}){sup 9}Be reaction peak.
  • Diamond exhibits many properties such as an outstanding radiation hardness and fast response time both important to design detectors working in extremely radioactive environments. Among the many applications these devices can be used for, there is the development of a fast and radiation hard neutron detector for the next generation of fusion reactors, such as the International Thermonuclear Experimental Reactor project, under construction at Cadarache in France. A technology to routinely produce electronic grade synthetic single crystal diamond detectors was recently developed by our group. One of such detectors, with an energy resolution of 0.9% as measured using an {supmore » 241}Am{alpha} particle source, has been heavily irradiated with 14.8 MeV neutrons produced by the Frascati Neutron Generator. The modifications of its spectroscopic properties have been studied as a function of the neutron fluence up to 2.0x10{sup 14} n/cm{sup 2}. In the early stage of the irradiation procedure an improvement in the spectroscopic performance of the detector was observed. Subsequently the detection performance remains stable for all the given neutron fluence up to the final one thus assessing a remarkable radiation hardness of the device. The neutron damage in materials has been calculated and compared with the experimental results. This comparison is discussed within the nonionizing energy loss (NIEL) hypothesis, which states that performance degradation is proportional to NIEL.« less