Foton-M4 Radiation Dosimetry

Launch: 2050 UT 7/19/2014 (Baikonur, Kazakhstan)
Landing: 0918 UT 9/1/2014 (Orenburg region, Russia)
Duration: 44 days
Orbit: apogee 571 km; perigee 258 km; inclination 64.9 degree

Detectors:
The passive dosimetry packages were housed in four identical boxes (“BOX #1-4”) distributed around the descent module (Fig. 1) at locations as indicated in Fig. 2. Each package consisted of six thermoluminescent detectors (TLD) and two layers of solid state nuclear track-etch detectors (SSNTD). The TLD were sensitive to the low LET components of the radiation field inside the module and the SSNTD were sensitive to the high LET components. An additional box, Box #5, was mounted outside the module.

For details of the measurements see:
A. Strádi et al., Cosmic radiation measurements on the Foton-M4 satellite by passive detectors. Acta Astronautica 131 110-112 (2017).

Fig. 1. Foton-M4 satellite (credit: Roscosmos)

Fig. 2. Interior of the satellite (credit: Roscosmos)

 

SSNTD data: Dosimetric quantities obtained from the LET spectra (above 10 keV μm−1)

Box #1 #2 #3 #4 #5
D (μGy/day) 41 51 49 52 75
H (μSv/day) 520 617 532 626 437
Q 12.7 12.2 10.9 12.0 5.8

 

TLD data: Absorbed dose rates measured in the low LET (≤10 keV μm−1) region of space radiation

Box #1 #2 #3 #4 #5
D (μGy/day) 374 408 532 563 1078
SD (%) 7 7 7 3 8

 

Convolved data of SSNTD and TLD measurements:

Box #1 #2 #3 #4 #5
D corr. (μGy/day) 366 398 525 551 105
D total (μGy/day) 407 448 574 603 1129
H total (μSv/day) 887 1014 1057 1177 1412
Q 2.2 2.3 1.8 2.0 1.3

Notes:

  • D = the absorbed dose rates
  • H = dose equivalent rates
  • Q = quality factors
  • D corr. = the corrected absorbed dose rate

Reference: A. Strádi et al., Cosmic radiation measurements on the Foton-M4 satellite by passive detectors. Acta Astronautica 131 (2017) 110-112.