Measurements of neutrons at JET by means of the activation methods

Prokopowicz, R.; Bienkowska, B.; Drozdowicz, Krzysztof; Jednoróg, S.; Kowalska-Strzęciwilk, E.; Murari, A.; Popovichev, S.; Pytel, Krzysztof; Scholz, M.; Szydlowski, A.; Syme, B.; Tracz, Grzegorz; Contributors, Jet‐Efda

doi:10.1016/j.nima.2011.01.128

Cited by 21 publications

(11 citation statements)

References 3 publications

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“…Typically, tokamaks and other bigger devices are equipped with automated, gas-driven tubes, known as pneumatic transport systems (PTS), for transport of the samples between the irradiation ends, storage and gammameasurement stations. The JET device in Culham (UK) [2], NPI's cyclotron-based white neutron source [3] and many planned facilities, like ITER [1] and its Test Blanket Modules (TBM) [4], the High-Flux Test Module (HFTM) of the Early Neutron Source (ENS) [5], etc. feature such integrated PTS for high-energy neutron spectrometry.…”

Section: Activation Foil Spectrometry In Fusionmentioning

confidence: 99%

Comparative survey of evaluated nuclear data libraries for fusion-relevant neutron activation spectrometry

et al. 2020

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The neutron flux-spectrum in a fusion device is frequently determined with activation foils and adjustment of a guess-spectrum in unfolding codes. Spectral-adjustment being a rather complex and uncertain procedure, we are carefully streamlining and evaluating it for upcoming experiments. Input nuclear cross-section data holds a vital position in this. This paper presents a survey of common dosimetry reactions and available data files relevant for fusion applications. While the IRDFF v1.05 library is the recommended source, many reactions of our interest are found missing in this. We investigated other standard sources: ENDF/B-VIII.0, EAF-2010, TENDL-2017, JENDL-4.0 etc. And, we analysed two experiments to ascertain the sensitivity of the spectral adjustment to the choice of nuclear data. One was performed with D-D (approx. 2.5 MeV peak) neutrons at the Joint European Torus (JET) machine and another with a white neutron field (approx. 33 MeV endpoint energy) at Nuclear Physics Institute (NPI) of Řež. Choice of cross-section source has affected the integral fluxes (<5%), reaction rates (<10%), total fluxes in some sensitive energy-regions (>20%) and individual group fluxes (<30%). Based on this experience, essential qualitative conclusions are made to improve the fusion activation-spectrometry.

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Section: Activation Foil Spectrometry In Fusionmentioning

confidence: 99%

Comparative survey of evaluated nuclear data libraries for fusion-relevant neutron activation spectrometry

et al. 2020

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“…Among all the materials possibly available [5,12], indium is the most proper for DD neutron measurement. The indium sample is composed of two isotopes 115 In and 113 In, and their natural abundances are 95.7% and 4.3%, respectively.…”

Section: The Measurement Principlementioning

confidence: 99%

“…Thus the neutron yield is one of the most important parameter to characterize ICF experiment performance. The activation diagnostic is a good substitute for the plastic scintillator detector at higher neutron yield ( >10 10 ) [5][6][7][8], which will improve the neutron yield measurement accuracy of implosion experiments conducted on Shenguang-III laser facility. Currently, the implosion capsules used on Shenguang-III facility are mostly filled with deuterium-deuterium (DD) fuel, and the DD neutron yield can be measured by an indium activation diagnostic [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

The Calibration of the DD Neutron Indium Activation Diagnostic

Zha

Chen

Liu

et al. 2015

Plasma Sci. Technol.

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The indium activation diagnostic was calibrated on an accelerator neutron source in order to diagnose deuterium-deuterium (DD) neutron yields of implosion experiments on Shenguang-III facility. The scattered neutron background of the accelerator room was measured by placing a polypropylene shield in front of indium sample, in order to correct the calibrated factor of this activation diagnostic. The proper size of this shield was given by Monte Carlo simulation software. The affect from some other activated nuclei on the calibration was verified by judging whether the measured curve obeys exponential decay and contrasting the half life of the activated sample. The calibration results showed that the linear range reached up to 100 cps net count rate in the full energy peak of interest, the scattered neutron background of accelerator room was about 9% of the total neutrons and the possible interferences mixed scarcely in the sample. Subtracting the portion induced by neutron background, the calibrated factor of our sample was 4.52 × 10 −7 counts/n with uncertainty of 4.3%.

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“…These techniques were used to measure e.g. neutron fluence at chosen locations around the machine, even inside the vacuum vessel close to the vessel walls [ 3 ]. Supported by neutron transport calculations the activation technique can provide information on the Y n and released fusion power.…”

Section: Plasmas Diagnostics Based Upon Chosen Nuclear Reactionmentioning

confidence: 99%

The application of selected radionuclides for monitoring of the D–D reactions produced by dense plasma-focus device

Jednoróg

Szydlowski

Bienkowska

et al. 2014

J Radioanal Nucl Chem

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The dense plasma focus (DPF) device—DPF-1000U which is operated at the Institute of Plasma Physics and Laser Microfusion is the largest that type plasma experiment in the world. The plasma that is formed in large plasma experiments is characterized by vast numbers of parameters. All of them need to be monitored. A neutron activation method occupies a high position among others plasma diagnostic methods. The above method is off-line, remote, and an integrated one. The plasma which has enough temperature to bring about nuclear fusion reactions is always a strong source of neutrons that leave the reactions area and take along energy and important information on plasma parameters and properties as well. Silver as activated material is used as an effective way of neutrons measurement, especially when they are emitted in the form of short pulses like as it happens from the plasma produced in Dense Plasma-Focus devices. Other elements such as beryllium and yttrium are newly introduced and currently tested at the Institute of Plasma Physics and Laser Microfusion to use them in suitable activation neutron detectors. Some specially designed massive indium samples have been recently adopted for angular neutrons distribution measurements (vertical and horizontal) and have been used in the recent plasma experiment conducted on the DPF-1000U device. This choice was substantiated by relatively long half-lives of the neutron induced isotopes and the threshold character of the 115In(n,n′)115mIn nuclear reaction.

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Measurements of neutrons at JET by means of the activation methods

Cited by 21 publications

References 3 publications

Comparative survey of evaluated nuclear data libraries for fusion-relevant neutron activation spectrometry

Comparative survey of evaluated nuclear data libraries for fusion-relevant neutron activation spectrometry

The Calibration of the DD Neutron Indium Activation Diagnostic

The application of selected radionuclides for monitoring of the D–D reactions produced by dense plasma-focus device

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