TItle: Recent Developments and Achievements in Space Radiation Research

Speaker: Prof. ZHOU Dazhuang (Senior Scientist at NASA, guest professor at National Space Science Center, CAS)

Host: Prof. WANG Huanyu, Deputy Director of IHEP

Time: 15:00, November 25, 2011

Place: Room C305, IHEP Main Building

Abstract:

Radiation fields of particles in LEO are composed of GCR (galactic cosmic rays), SEP (solar energetic particles), SAA (south Atlantic anomaly) and albedo neutrons and protons scattered from the Earth’s atmosphere. When the primary particles pass through the space craft wall and interior material of instruments/structures, variety of secondary particles with wide range of charges and energies are produced, then a very complicated radiation field is generated. This radiation field is far different from the radiation sources we meet on the ground and nova methods/detectors are needed for the measurements and research of the radiation field.

The key information of space radiation is LET (Linear Energy Transfer), the main purpose and may be the final task of radiation researches is the radiation risk. Radiation risk is dominated by particles with high LET (≥ 10 keV/μm water), therefore, methods and detectors which can provide us with LET spectra (differential and integral particle fluence, absorbed dose and dose equivalent) must be used. The radiation risk can be calculated based on LET spectra measured, the cross section of radiation risk obtained in radiobiology and results obtained for the different organs of Matroshka astronaut phantom. The methods developed for space radiation can also apply to career radiation, medical radiation and ground environmental radiation.

In recent years, NASA has being using active TEPC (Tissue Equivalent Proportional Counter) and passive CR-39 detectors using LET spectrum method to measure radiation for the selected monitoring areas and for astronauts on STS and ISS. This talk presents the main methods, experiments and achievements in space radiation research obtained by NASA-JSC and ESA since STS-114 space mission. Some potential applications for the high-lighted topics in physics research related to radiation detection and protection will also be presented and discussed.