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PostDoc position at LNHB in France available

Study of X-ray emitting radionuclides for dosimetry in reactors (Engineering sciences / Metrology)

The LNHB (Laboratoire National Henri Becquerel) is the French metrology laboratory in the field of ionizing radiation. One of the tasks of the laboratory is the measurement of radionuclides activity (in becquerels) and the determination of radionuclides decay data. The measurement of the activity of X-ray emitting radionuclides, in the energy range below 100 keV, presents several difficulties that limit the accuracy of the result. These include the calibration of the detector efficiency and, in general, the large uncertainties associated with X-ray emission intensities. In addition, the effects of self-attenuation of X-rays in standard sources or samples lead to important corrections that must be controlled.
Among the important applications of the measurement of X-ray emitters, the dosimetry in reactor, which allows to determine the neutron fluence received during an irradiation and to characterize the spectrum, is based on the analysis of the activity of irradiated dosimeters. These dosimeters are made of pure metals or alloys of perfectly known composition, some of which are subject to activation or fission reactions under the effect of neutrons. For example, the reactions 93Nb(n,n')93mNb and 103Rh(n,n')103mRh are of primary importance for reactor dosimetry and are particularly interesting for characterizing neutron fluxes around 1 MeV.
The task of the postdoc will consist in:

  • Exploiting the results of the efficiency calibration of a high purity germanium (HPGe) detector using a cryogenic electrical substitution radiometer and transfer photodiodes. This will be used to measure the absolute X-ray emission intensities of radionuclides used as standard for the calibration of detectors (133Ba, 152Eu, etc.);
  • Improve the knowledge of photon emission intensities following the decay of 93mNb, 103Pd and 103mRh;
  • Critically analyzing published data on these radionuclides and to contribute to the evaluation and publication of their decay schemes.

Contract duration: 1 year (possible renewal 1 time)
Desired starting date: 01/03/2023
Location: Laboratoire National Henri Becquerel - CEA Saclay- 911914 GIF-SUR-YVETTE Cedex www.lnhb.fr
Candidate profile: The candidate must have a PhD in physics with knowledge in nuclear instrumentationand/or atomic physics. He/she must have a solid knowledge of radiation-matter interactions and an interest in laboratory experiments. He/she should demonstrate good critical thinking skills and be able to analyze the results in details.

Please find further information
in French at https://www.emploi.cea.fr/job/job-etude-des-radionucleides-emetteurs-x-pour-la-dosimetrie-en-reacteur-h-f_25674.aspx
and in English at https://instn.cea.fr/en/post-doctorat/study-of-x-ray-emitting-radionuclides-for-reactor-dosimetry/

Application: Please send a curriculum vitae and a motivation letter to:
Marie-Christine LÉPY
Bât. 602
91191 Gif-sur-Yvette
Tél. : +33 1 69 08 24 48
E-mail : marie-christine.lepy(at)cea.fr

This entry was posted on Friday, March 3rd, 2023 a 09:51 am.

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