Speaker
Livio Narici
(INFN Tor Vergata & Department of Physics University of Rome Tor Vergata)
Description
Mitigation of the risks due to radiation exposure is a most important issue for the future space voyages needed for human space exploration. Studies aimed at the detailed understanding of the radiation effects on humans are showing a panorama of risks strongly dependent on several specific characteristic of the radiation. As an example high Linear Energy Transfer (LET) charged radiation have been shown to produce cellular/molecular damages leading to a higher risk determination than the same dose of low LET radiation.
Detailed measurements of the radiation environment in the International Space Station serve as risk monitoring for the crew but, most important, as basis for model validation. ISS radiation environment is indeed the closest available replica of the deep space environment in a spacecraft (especially at the high latitude passages).
The ALTEA detector system started operations in 2006 in the ISS. It features six silicon particle telescopes, each one composed by six planes striped either along the short side of the plane or along the long side (X and Y directions). Each detector is able to reconstruct the trajectory of the impinging ions. Under certain circumstances the charge and the kinetic energy of the ion can be calculated. In sum the ALTEA system can measure in 3D the radiation environment and perform nuclear identification. The detector is able to measure LET (in silicon) from 3 to 800 keV/µm, so it is marginally sensitive to protons and Helium, and fully sensitive to higher Z ions up to relativistic Molybdenum.
An update of ALTEA has been recently selected by ASI and consists in a new detector to be coupled to the existing ones. The prototype of this detector has been developed for a previous national project and uses scintillators and Silicon Photomultipliers and is able to perform Time of Flight measurements. This upgrade will complete the charge range sensitivity of ALTEA (1≤Z≤42) and provide improvements in the Z discrimination ability via independent measurements of kinetic energy.
The new combined detector will be a perfect benchmark for new management software and analysis risk – algorithms to be used in a future miniaturized portable (personal) system.
In this paper we present latest analyses from ALTEA measurements and we discuss the possible future perspectives.
Primary author
Livio Narici
(INFN Tor Vergata & Department of Physics University of Rome Tor Vergata)
