Johann Plagnard

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The effect of the photon energy on the radiosensitization produced by iododeoxyuridine (IUdR) was examined using Chinese hamster cells in vitro. Radiosensitization by IUdR was considerably higher for 60 keV photons from 241Am sources than for the 860 keV photons (average energy) from 226Ra sources, under continuous low dose rate conditions applicable to(More)
The EUROMET project 428 examines efficiency transfer results for Ge gamma-ray spectrometers when the efficiency is known for a reference point source geometry. For this, different methods are used, such as Monte Carlo simulation or semi-empirical computation. The exercise compares the application of these methods to the same selected experimental cases to(More)
The photon-scattering effect was studied in the low-energy range 15-80keV with planar and coaxial germanium detectors. Different experimental tests have been conducted with a point source, progressively reducing the matter around the radioactive deposit, to investigate the origin and characteristics of the different spectrum components due to scattered(More)
Measurements of (241)Am L X-ray emission probabilities were conducted using both HPGe and Si(Li) detectors. The efficiency calibrations of these detectors were performed by means of a tunable, monochromatic photon beam and the determination of the thickness of absorbing materials inside the detector. These efficiency calibrations were obtained without any(More)
In gamma-ray spectrometry, new acquisition systems based on digital signal processing are now commercially available. In order to determine their performance at high count rates, the Commissariat à l'Energie Atomique (CEA), Laboratoire National Henri Becquerel has tested several of these systems. These tests have clearly shown that the performance levels(More)
Applications such as environment monitoring implying alpha emitters activity measurement associated with isotope identification, require high-energy resolution detectors. Conventional silicon detectors are inexpensive therefore widely used, although intrinsically limited in energy resolution. Thermal detection principle of cryogenic detectors introduces a(More)
The ETNA software has been developed to compute efficiency transfer and coincidence summing corrections. Different experiments are combined to test the validity of this last facility. Point sources with multi-gamma emitters are measured at several source-to-detector distances. Experimental correction factors are determined from the variation in the peaks'(More)
A tunable monochromatic X-ray source operating in the 1-20 keV energy range is described. An X-ray tube provides initial photons. A dispersive crystal performs the energy selection, according to Bragg's law. An X-ray detector is connected to the monochromator fixed exit. This setup can be used for metrological studies. A first application consists in(More)
Quantitative solid sources are used widely in the field of radionuclide metrology. With the aim to improve the detection efficiency for electrons and x-rays, a comparative study between two source drying techniques has been undertaken at LNE-Laboratoire National Henri Becquerel (LNE-LNHB, France). In this paper, freeze-drying using commercial equipment is(More)
(67)Ga is an interesting radionuclide as it is widely used in nuclear medicine. The meta-stable level related to the 93.3keV gamma-transition represents the main difficulty when using the coincidence method to standardize this radionuclide. The 4pi(LS)beta-gamma anti-coincidence system implemented at LNHB is based on the use of electronic modules(More)
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