Space dosimetry with luminescent detectors

Parisi Alessio

Promoter

Mégret Patrice, (UMONS), Patrice.MEGRET@umons.ac.be

SCK•CEN Mentor

Van Hoey Olivier
olivier.van.hoey@sckcen.be
+32 14 33 27 09

SCK•CEN Co-mentor

Vanhavere Filip
filip.vanhavere@sckcen.be
+32 14 33 28 59

Expert group

RP Dosimetry and Calibration

PhD started

2015-10-01

Short project description

The radiation field in space is very complex, consisting of neutrons, electrons and high-energy heavy charged particles. Interaction of this primary radiation field with the materials from the spacecrafts, produces a shower of secondary particles that will also interact with the astronauts and the different experiments conducted in space. It is important to measure these absorbed and equivalent doses for radiation protection purposes of the astronauts, and for evaluation of the experiments in space. The radiation field in space is not constant, it depends on the altitude of the spacecraft, the solar activity, the location in the spacecraft,…

Objective

There are different types of radiation monitors present in the ISS (International Space Station), like active monitors and microdosimetric spectrometers. However, there is also a need for small and passive dosemeters to do mapping of the radiation field, to accompany small experiments (like biological samples) and to monitor the astronauts. It is still a challenge to measure the whole particle and energy range with small passive detectors. With thermoluminescent (TL) and optically luminescent(OSL) detectors it is relatively easy to measure the low LET part of the spectrum. For the high LET part mostly track etch detectors are used, which is a cumbersome and not very robust technique.

However, also with TL and OSL detectors information from the high LET part can be obtained, e.g. from the ratio of the high temperature peaks of the TL detectors. Some research on this has been done, but nobody has ever developed an algorithm to calculate the equivalent doses based on the combination of different TL and OSL detectors.

To do this, characterization of the responses is needed in high energy fields. Part of such characterization has already been done at SCK•CEN, and also a large data set from exposures at the ISS is available for analyses.

The PhD will focus on the development of an algorithm to measure the equivalent doses in space using different types of passive detectors. For this also simulations will be needed, and the interaction of the specific space radiation field in different locations on the detectors will need to be simulated. The method should not be limited to exposures in the ISS alone, but should also be usable in interplanetary missions, where the radiation field is different. It should be investigated if a good dosemeter for the astronauts can be developed using different luminescent detectors.