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PAssive Dosimeter for Life science Experiments in Space (PADLES)

Last Updated: July 14, 2015

Passive dosimeter packages and an analysis system are developed by JAXA for supporting life science experiments. They provide environmental data for space radiation. In the ISS, we are planning to measure space radiation by a combination of Nuclear track detectors and Thermoluminescent Dosimetry. TLD are used for estimating an absorbed dose for space radiation in the LET region below 10 keV/µm. CR-39 plastic plates are used for measuring LET distributions of heavy-charged particles in the LET region above 10 keV/µm. We estimate the absorbed dose and dose equivalent above 10 keV/µm from the LET distributions.

  • PADLES is a compact and battery-less Dosimeter, having the advantage of no necessity of crew times and package for setting extremely close to biological samples. (The basic PADLES external form: 2.5 cm x 2.5 cm x 0.4cm)
  • The dosimeters will be adjacent to biological samples on board at all times. It is available to use at storage temperatures from -80 deg. C to +37deg. C.
Passive dosimeter system for life science experiments in the ISS
Detectors Measurements Particles/
LET range

TLD MSO-S Absorbed dose*1 Photons,
Charged particles
0.2 - 10

CR-39 HARZLAS(TD-1/TNF-1) LET spectrum Charged particles 2 - 1000
  BARYOTRK/HARZLAS(TD-1) particle tracking HZE*3 particles > 40 *4

TLD MSO-S Absorbed Dose Photons,
Charged particles
0.2 - 1000
CR-39 HARZLAS(TD-1/TNF-1) Equivalent Dose*1 Photons,
Charged particles
    Effective Quality Factor*2 Photons,
Charged particles

Temperature -80 - +40 deg. C
Gas 1atm, the air
Package Size 25mmW*25mmL*4mmt typical
On Board Period a standard period: 3 month (minimum:1 week - maximum :1 year)

*1Integral flux on board period
*2an average on board period
*3High-atomic-number (Z) and high-energy (E) charged particles.
*4It's suitable for charged particles having high atomic number more than Si ion.

See also:
Free-Space PADLES
PADLES database

  1. H. Tawara, S. Kamigaichi, M. Masukawa, A. Nagamatsu, T. Nakano, H. Kumagai, M. Masaki, E.Kurano, H. Yasuda, N. Yasuda, : Development of techniques for space-radiation dosimetry using passive detectors, Ionizing Radiation, Vol.27, No.4, 29-41(2001) (in Japanese).
  2. H. Tawara, M. Masukawa, A. Nagamatsu, : Space-radiation disimetry using CR-39
    and TLD integrationg dosimeters, , Ionizing Radiation, Vol.28, No.2, 181-194 (2002) (in Japanese).
  3. A. Nagamatsu, M. Masukawa, S. Kamigaichi, H. Kumagai, M. Masaki, N. Yasuda, H. Yasuda, E. Benton, T. Hayashi, H. Tawara:Development of the space radiation dosimetry system ‘PADLES、RADIATION DETECTORS AND THEIR USES 2006-7, p26-36 (2006).
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