Monitoring the fast neutrons in a high flux: The case for242Pu fission chambers

P. Filliatre; Christian Jammes; L. Oriol; B. Geslot; L. Vermeeren

doi:10.1109/ANIMMA.2009.5503819

Monitoring the fast neutrons in a high flux: The case for²⁴²Pu fission chambers

P. Filliatre, Christian Jammes, L. Oriol, B. Geslot, L. Vermeeren

Research output › peer-review

Abstract

Fission chambers are widely used for on-line monitoring of neutron fluxes in irradiation reactors. A selective measurement of a component of interest of the neutron flux is possible in principle thanks to a careful choice of the deposit material. However, measuring the fast component is challenging when the flux is high (up to 10¹⁵ n/cm²/s) with a significant thermal component. The main problem is that the isotopic content of a material selected for its good response to fast neutrons evolves with irradiation, so that the material is more and more sensitive to thermal neutrons. Within the framework of the FNDS (Fast Neutron Detector System) project, we design tools that simulate the evolution of the isotopic composition and fission rate for several deposits under any given flux. In the case of a high flux with a significant thermal component, ²⁴²Pu is shown after a comprehensive study of all possibilities to be the best choice for measuring the fast component, as long as its purity is sufficient. If an estimate of the thermal flux is independently available, one can correct the signal for that component. This suggests a system of two detectors, one of which being used for such a correction. It is of very high interest when the detectors must be operated up to a high neutron fluence.

Original language	English
Title of host publication	ANIMMA 2009
Subtitle of host publication	2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications
Publisher	IEEE Computer Society and the Association for Computing Machinery
ISBN (Print)	9781424452088
DOIs	https://doi.org/10.1109/ANIMMA.2009.5503819
State	Published - 2009
Event	2009 - ANIMMA : 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications - CEA, Marseille Duration: 7 Jun 2009 → 10 Jul 2009

Publication series

Name	ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications
Publisher	IEEE

Conference

Conference	2009 - ANIMMA
Abbreviated title	ANIMMA
Country/Territory	France
City	Marseille
Period	2009-06-07 → 2009-07-10

ASJC Scopus subject areas

Nuclear Energy and Engineering

Access to Document

10.1109/ANIMMA.2009.5503819License: Unspecified

Cite this

Filliatre, P., Jammes, C., Oriol, L., Geslot, B., & Vermeeren, L. (2009). Monitoring the fast neutrons in a high flux: The case for²⁴²Pu fission chambers. In ANIMMA 2009: 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications Article 5503819 (ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications). IEEE Computer Society and the Association for Computing Machinery. https://doi.org/10.1109/ANIMMA.2009.5503819

Filliatre, P. ; Jammes, Christian ; Oriol, L. et al. / Monitoring the fast neutrons in a high flux : The case for²⁴²Pu fission chambers. ANIMMA 2009: 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications. IEEE Computer Society and the Association for Computing Machinery, 2009. (ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications).

@inproceedings{d9ac766c39f54df6bf26fd9e2c1d8789,

title = "Monitoring the fast neutrons in a high flux: The case for242Pu fission chambers",

abstract = "Fission chambers are widely used for on-line monitoring of neutron fluxes in irradiation reactors. A selective measurement of a component of interest of the neutron flux is possible in principle thanks to a careful choice of the deposit material. However, measuring the fast component is challenging when the flux is high (up to 1015 n/cm2/s) with a significant thermal component. The main problem is that the isotopic content of a material selected for its good response to fast neutrons evolves with irradiation, so that the material is more and more sensitive to thermal neutrons. Within the framework of the FNDS (Fast Neutron Detector System) project, we design tools that simulate the evolution of the isotopic composition and fission rate for several deposits under any given flux. In the case of a high flux with a significant thermal component, 242Pu is shown after a comprehensive study of all possibilities to be the best choice for measuring the fast component, as long as its purity is sufficient. If an estimate of the thermal flux is independently available, one can correct the signal for that component. This suggests a system of two detectors, one of which being used for such a correction. It is of very high interest when the detectors must be operated up to a high neutron fluence.",

keywords = "Fission reactor measurements, Neutron detectors, Simulation",

author = "P. Filliatre and Christian Jammes and L. Oriol and B. Geslot and L. Vermeeren",

year = "2009",

doi = "10.1109/ANIMMA.2009.5503819",

language = "English",

isbn = "9781424452088",

series = "ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications",

publisher = " IEEE Computer Society and the Association for Computing Machinery",

booktitle = "ANIMMA 2009",

note = "2009 - ANIMMA : 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications , ANIMMA ; Conference date: 07-06-2009 Through 10-07-2009",

}

Filliatre, P, Jammes, C, Oriol, L, Geslot, B & Vermeeren, L 2009, Monitoring the fast neutrons in a high flux: The case for²⁴²Pu fission chambers. in ANIMMA 2009: 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications., 5503819, ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications, IEEE Computer Society and the Association for Computing Machinery, 2009 - ANIMMA , Marseille, France, 2009-06-07. https://doi.org/10.1109/ANIMMA.2009.5503819

Monitoring the fast neutrons in a high flux: The case for²⁴²Pu fission chambers. / Filliatre, P.; Jammes, Christian; Oriol, L. et al.
ANIMMA 2009: 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications. IEEE Computer Society and the Association for Computing Machinery, 2009. 5503819 (ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications).

Research output › peer-review

TY - GEN

T1 - Monitoring the fast neutrons in a high flux

T2 - 2009 - ANIMMA

AU - Filliatre, P.

AU - Jammes, Christian

AU - Oriol, L.

AU - Geslot, B.

AU - Vermeeren, L.

PY - 2009

Y1 - 2009

N2 - Fission chambers are widely used for on-line monitoring of neutron fluxes in irradiation reactors. A selective measurement of a component of interest of the neutron flux is possible in principle thanks to a careful choice of the deposit material. However, measuring the fast component is challenging when the flux is high (up to 1015 n/cm2/s) with a significant thermal component. The main problem is that the isotopic content of a material selected for its good response to fast neutrons evolves with irradiation, so that the material is more and more sensitive to thermal neutrons. Within the framework of the FNDS (Fast Neutron Detector System) project, we design tools that simulate the evolution of the isotopic composition and fission rate for several deposits under any given flux. In the case of a high flux with a significant thermal component, 242Pu is shown after a comprehensive study of all possibilities to be the best choice for measuring the fast component, as long as its purity is sufficient. If an estimate of the thermal flux is independently available, one can correct the signal for that component. This suggests a system of two detectors, one of which being used for such a correction. It is of very high interest when the detectors must be operated up to a high neutron fluence.

AB - Fission chambers are widely used for on-line monitoring of neutron fluxes in irradiation reactors. A selective measurement of a component of interest of the neutron flux is possible in principle thanks to a careful choice of the deposit material. However, measuring the fast component is challenging when the flux is high (up to 1015 n/cm2/s) with a significant thermal component. The main problem is that the isotopic content of a material selected for its good response to fast neutrons evolves with irradiation, so that the material is more and more sensitive to thermal neutrons. Within the framework of the FNDS (Fast Neutron Detector System) project, we design tools that simulate the evolution of the isotopic composition and fission rate for several deposits under any given flux. In the case of a high flux with a significant thermal component, 242Pu is shown after a comprehensive study of all possibilities to be the best choice for measuring the fast component, as long as its purity is sufficient. If an estimate of the thermal flux is independently available, one can correct the signal for that component. This suggests a system of two detectors, one of which being used for such a correction. It is of very high interest when the detectors must be operated up to a high neutron fluence.

KW - Fission reactor measurements

KW - Neutron detectors

KW - Simulation

UR - http://www.scopus.com/inward/record.url?scp=77954946676&partnerID=8YFLogxK

U2 - 10.1109/ANIMMA.2009.5503819

DO - 10.1109/ANIMMA.2009.5503819

M3 - In-proceedings paper

AN - SCOPUS:77954946676

SN - 9781424452088

T3 - ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications

BT - ANIMMA 2009

PB - IEEE Computer Society and the Association for Computing Machinery

Y2 - 7 June 2009 through 10 July 2009

ER -

Filliatre P, Jammes C, Oriol L, Geslot B, Vermeeren L. Monitoring the fast neutrons in a high flux: The case for²⁴²Pu fission chambers. In ANIMMA 2009: 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications. IEEE Computer Society and the Association for Computing Machinery. 2009. 5503819. (ANIMMA 2009 - 2009 1st International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications). doi: 10.1109/ANIMMA.2009.5503819