Analysis of the CONRAD computational problems expressing only stochastic uncertainties: neutrons and protons

Gualdrini, G.; Tanner, R.J.; Agosteo, S.; Pola, A.; Bedogni, R.; Ferrari, P.; Lacoste, V.; Bordy, Jean-Marc; Chartier, J.-L.; Carlan, L. de; Ros, J M Gomez; Großwendt, B.; Kodeli, I.; Price, R. A.; Rollet, S.; Schultz, F.; Siebert, Bernd; Terrissol, M.; Zankl, M.

doi:10.1093/rpd/ncn241

Cited by 6 publications

(4 citation statements)

References 2 publications

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“…A tin (Sn) layer was placed above the steel to filter additional X-rays that were formed during γ-filtering in the steel. The moderated ~0.1 eV neutrons [ 19 ] travelled through an air layer before finally reaching the Gd-coated Si wafer. The total source to-detector distance was 11.7 cm, close to the 10.6 cm reported previously [ 14 ].…”

Section: Resultsmentioning

confidence: 99%

Microfabrication of a gadolinium-derived solid-state sensor for thermal neutrons

Pfeifer

Achyuthan

Allen

et al. 2017

Journal of Radiation Research

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Neutron sensing is critical in civilian and military applications. Conventional neutron sensors are limited by size, weight, cost, portability and helium supply. Here the microfabrication of gadolinium (Gd) conversion material–based heterojunction diodes for detecting thermal neutrons using electrical signals produced by internal conversion electrons (ICEs) is described. Films with negligible stress were produced at the tensile-compressive crossover point, enabling Gd coatings of any desired thickness by controlling the radiofrequency sputtering power and using the zero-point near p(Ar) of 50 mTorr at 100 W. Post-deposition Gd oxidation–induced spallation was eliminated by growing a residual stress-free 50 nm neodymium-doped aluminum cap layer atop Gd. The resultant coatings were stable for at least 6 years, demonstrating excellent stability and product shelf-life. Depositing Gd directly on the diode surface eliminated the air gap, leading to a 200-fold increase in electron capture efficiency and facilitating monolithic microfabrication. The conversion electron spectrum was dominated by ICEs with energies of 72, 132 and 174 keV. Results are reported for neutron reflection and moderation by polyethylene for enhanced sensitivity, and γ- and X-ray elimination for improved specificity. The optimal Gd thickness was 10.4 μm for a 300 μm-thick partially depleted diode of 300 mm2 active surface area. Fast detection (within 10 min) at a neutron source-to-diode distance of 11.7 cm was achieved with this configuration. All ICE energies along with γ-ray and Kα,β X-rays were modeled to emphasize correlations between experiment and theory. Semi-conductor thermal neutron detectors offer advantages for field-sensing of radioactive neutron sources.

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Section: Resultsmentioning

confidence: 99%

Microfabrication of a gadolinium-derived solid-state sensor for thermal neutrons

Pfeifer

Achyuthan

Allen

et al. 2017

Journal of Radiation Research

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“…Whilst MC methods are well benchmarked, their use is still subject to significant user influence. Intercomparisons have been used to demonstrate that, even for relatively simple problems, users can get results that are in error by several orders of magnitude (Gualdrini et al., 2008). These problems can result from minor mathematical errors, but they can also be caused by erroneous specification of the problem or the use of inappropriate physics.…”

Section: Eurados Scientific Work Programmementioning

confidence: 99%

The work programme of EURADOS on internal and external dosimetry

et al. 2018

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Since the early 1980s, the European Radiation Dosimetry Group (EURADOS) has been maintaining a network of institutions interested in the dosimetry of ionising radiation. As of 2017, this network includes more than 70 institutions (research centres, dosimetry services, university institutes, etc.), and the EURADOS database lists more than 500 scientists who contribute to the EURADOS mission, which is to promote research and technical development in dosimetry and its implementation into practice, and to contribute to harmonisation of dosimetry in Europe and its conformance with international practices. The EURADOS working programme is organised into eight working groups dealing with environmental, computational, internal, and retrospective dosimetry; dosimetry in medical imaging; dosimetry in radiotherapy; dosimetry in high-energy radiation fields; and harmonisation of individual monitoring. Results are published as freely available EURADOS reports and in the peer-reviewed scientific literature. Moreover, EURADOS organises winter schools and training courses on various aspects relevant for radiation dosimetry, and formulates the strategic research needs in dosimetry important for Europe. This paper gives an overview on the most important EURADOS activities. More details can be found at www.eurados.org .

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“…Various transport codes are suited to calculate the response matrix of a BSS. A recent computational exercise (38) organised in the framework of the CONRAD project demonstrated that the MCNP family is used in the majority of the cases. FLUKA (39,40) and GEANT 4 (41) have also been used, obtaining comparable results.…”

Section: The Response Of the Bssmentioning

confidence: 99%

Neutron spectrometry with Bonner Spheres for area monitoring in particle accelerators

Bedogni

2011

Radiation Protection Dosimetry

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Selecting the instruments to determine the operational quantities in the neutron fields produced by particle accelerators involves a combination of aspects, which is peculiar to these environments: the energy distribution of the neutron field, the continuous or pulsed time structure of the beam, the presence of other radiations to which the neutron instruments could have significant response and the large variability in the dose rate, which can be observed when moving from areas near the beam line to free-access areas. The use of spectrometric techniques in support of traditional instruments is highly recommended to improve the accuracy of dosimetric evaluations. The multi-sphere or Bonner Sphere Spectrometer (BSS) is certainly the most used device, due to characteristics such as the wide energy range, large variety of active and passive detectors suited for different workplaces, good photon discrimination and the simple signal management. Disadvantages are the poor energy resolution, weight and need to sequentially irradiate the spheres, leading to usually long measurement sessions. Moreover, complex unfolding analyses are needed to obtain the neutron spectra. This work is an overview of the BSS for area monitoring in particle accelerators.

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Analysis of the CONRAD computational problems expressing only stochastic uncertainties: neutrons and protons

Cited by 6 publications

References 2 publications

Microfabrication of a gadolinium-derived solid-state sensor for thermal neutrons

Microfabrication of a gadolinium-derived solid-state sensor for thermal neutrons

The work programme of EURADOS on internal and external dosimetry

Neutron spectrometry with Bonner Spheres for area monitoring in particle accelerators

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