Laurent Desorgher

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The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present(More)
The assessment of the exposure to cosmic radiation onboard aircraft is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher onboard aircraft than at ground level and its intensity depends on the solar activity. The dose is usually estimated using codes validated by the experimental data. In(More)
[1] Currently a cosmic ray cloud connection (CRC) hypothesis is subject of an intense controversial debate. It postulates that galactic cosmic rays (GCR) intruding the Earth’s atmosphere influence cloud cover. If correct it would have important consequences for our understanding of climate driving processes. Here we report on an alternative and stringent(More)
1 Sodankylä Geophysical Observatory (Oulu unit), P.O.Box 3000, FIN-90014 University of Oulu, Finland,, 2 Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland 3 Solar-Terrestrial Influences Laboratory, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria 4 IFSI-Roma/INAF, Via del Fosso del Cavaliere, 100(More)
In January 2005 toward the end of solar activity cycle 23 the Sun was very active. Between 15 and 20 January 2005, the solar active region NOAA AR 10720 produced five powerful solar flares. In association with this major solar activity several pronounced variations in the ground-level cosmic ray intensity were observed. The fifth of these flares (X7.1)(More)
For upcoming exploration missions, space agencies advocate the development of a new promising technique to search for traces of extent or extinct life: the biochip use. As space is a hazardous environment, a main concern relies on the resistance of this device to a panel of harsh constraints. Within the framework of the BiOMAS (Biochip for Organic Matter(More)
Recent measurements of the high-energy charged particle environment with the Radiation Environment Monitor (REM) aboard the Russian Mir space station are presented. Ionizing dose rates in a silicon detector have been measured with two shieldings. The dose is mainly accumulated in two distinct areas, the South Atlantic Anomaly (SAA) and the region of closest(More)
Measurements of the South Atlantic Anomaly (SAA) made with the Radiation Environment Monitor (REM) aboard Mir from November 1994 to February 1996 are presented. During this period an increase of the SAA radiation by approximately 25% is observed, which coincides with a lowering of the radio solar flux. Radio solar flux is one of the parameters controlling(More)
Simulations with a Monte Carlo tool kit have been performed to determine the radiation environment a specific device, called a biochip, would face if it were placed into a rover bound to explore Mars' surface. A biochip is a miniaturized device that can be used to detect organic molecules in situ. Its specific detection part is constituted of proteins whose(More)
AIM The aim of this work was to assess the doses received by a diver exposed to a radiation source during maintenance work in the fuel transfer pool at a Swiss nuclear power plant, and to define whether the statutory limit was breached or not. METHOD Onsite measurements were carried out and different scenarios were simulated using the MicroShield Software(More)