Recent Radiation Monitoring Results: Expedition 10, 11 and STS-114

E. Semones, M. Weyland; B. Rutledge, T. Shelfer; R. Gaza; D. Zhou; A. Johnson; and N. Zapp WRMISS 10 Chiba, Japan

Lyndon B. Johnson Space Center 9/7/05 Mission Timeline

Launch Landing Expedition Status Duration Crew (GMT) (GMT)

19-Apr- 24-Oct- 188 days Gennady ISS-9 Flown 2004 2004 9 hr. Padalka, 03:19:00 12:36:00 17min. Michael Fincke

14-Oct- 24-Apr- 192 days Leroy Chiao, ISS-10 Flown 2004 2005 19 hr. Salizhan 03:06:00 22:08:00 2min. Sharipov

15-Apr- Estimated: 177 days Sergei In ISS-11 2005 10-Oct- 23 hr. Krikalev, Progress 00:46:25 2005 13min. John Phillips

Launch # Mission Landing Date Duration Inclination # Status Date Intl. EVA's Vehicle (Increment) (GMT) (hours) (°) Crew (GMT) Crew

13 days STS-114 26-Jul-2005 09-Aug-2005 Flown 21 hr. 51.6 7 1 3 Discovery (LF1) 14:39:01 12:11:00 31min.

International Space Station As Flown Altitude Profile (Based on MCC-M/USSP Tracked SV Data)

445.0 STS100 M Reb STS108 M-Reb STS-113 M Reb 240.3 442.5 STS102 M-Reb STS112 M Reb 238.9 440.0 STS92 M-Reb STS105 M-Reb STS111 M Reb 237.6 437.5 STS96 M-Reb STS106 M-Reb STS104 M-Reb STS110 M-Reb 236.2 435.0 STS88 M-Reb STS101 M-Reb STS98 M-Reb UF1 6P Reb 16P St g 234.9 432.5 7A Inc UF1 6P Reb 9A 9P Reb 10P St g Reb 13P Reb/ Inc 16P St g 233.5 430.0 1P Reb 7A Test UF1 Test O/ P UF2 8P Reb 10P St g Reb 13P Phase-01 15P St g Reb 232.2 427.5 2A Test 1P Test 5A1 Reb UF1 Test UF2 7P Reb 10P St g Reb 12P Phase 15P Phase/ Inc 230.8 425.0 1A/ R Insert ion 2A1 reb 1R Rend 5A1 Test 4R Reb/ Phs 8A Reb 11A/ 10P Reb 12P Phase 15P St g Reb 17P St g 229.5 422.5 FGB DAM DAM STS98 7P DAM 228.1 420.0 DAM (f ailed) 1P DAM DAM STS108 10P DAM 226.8 417.5 225.4 415.0 Sz-TM M ax Rndz Alt (425 km) 224.1 412.5 222.7 410.0 Sz-TM (1-4) M ax Dock/Sep (410 km) 221.4 407.5 220.0 405.0 218.7 402.5 217.3

400.0 216.0 e v e 397.5 214.6 a v 395.0 213.3 a H

392.5 211.9 H ,

, 390.0 210.6 p p 387.5 209.2 H

H ,

385.0 207.9 a , 382.5 206.5 a H

H 380.0 205.2 -

- 377.5 203.8 )

) 375.0 202.5 m

m 372.5 201.1 n ( k

( 370.0 199.8 .

t . 367.5 198.4 l t l

365.0 197.1 A

A t

362.5 195.7 t 360.0 194.4 n n a i a

357.5 193.0 r i r 355.0 191.7 a a 352.5 190.3 v v n I n 350.0 189.0 I 347.5 187.6 345.0 3P-M Dock 3S-SZ Dock 186.3 342.5 2P-M1 Dock 4R-DC Dock 8P M-Dock 6S Dock 13P M1 Dock 15P M Dock 184.9 340.0 2R-Sz Dock 5P-M Dock 4S Dock 10PM Dock 7S Dock 14P M1 Dock 183.6 337.5 1P Dock 4P-M1 Dock 7P-M1 Dock 5S Dock 12P M Dock 16P M Dock 182.2 335.0 1R-SM Dock 2S-Sz Dock 6P-M1 Dock 9PM1 Dock 11P M1 Dock 8S Dock 9S Dock 180.9 332.5 STS98 Dock STS-113 Dock 179.5 330.0 STS97 Dock STS105 Dock STS-112 Dock 178.2 327.5 STS92 Dock STS104 Dock STS-111 Dock 176.8 325.0 STS96 Dock STS106 Dock STS100 Dock STS-110 Dock 175.5 322.5 STS-88 Dock STS101 Dock STS102 Dock STS108 Dock 174.1 320.0 172.8 317.5 2S Sep 6S Sep 171.4 315.0 3P Sep DC ISM Sep 7P Sep 9P Sep 11P Sep 13P Sep 15P M Sep 170.1 312.5 2P Sep 4P Sep 3S Sep 4S Sep 1OP Sep 7S Sep 8S Sep 168.7 310.0 1P Sep 2R-Sz Sep 5P Sep 6P Sep 8P Sep 5S Sep 12P Sep 14P Sep 167.4 Solar Cycle Progression SRAG Operational Radiation Measurements Area monitoring devices • Passive detectors: Thermoluminescence Dosimeters (TLD), Optically Stimulated Luminescence detectors (OSLDs) and Plastic Nuclear Track Detectors (PNTD) • Active detectors: Tissue Equivalent Proportional Counters (TEPC) and Solid-State (Si) Detectors: IV-CPDS, EV-CPDS Personal dosimetry- Each crewmember carries a dosimeter for the duration of their mission.

• TLDs: LiF:Mg,Ti; CaF2:Tm • PNTD CR-39 (USF-4, 600 mm) • OSLDs: Luxel, “dots” and roll 22-24 detectors in Lexan holder at a depth of 0.18 g/cm^2 Space radiation dosimetry • What we want: Dose equivalent:

H = å Hi = å Di ´ Q(Li ) i i • NCRP 142, 2002 Recommendation 11, Equation 6.1:

H = QD + Q(L) D (L) dL OSLD /TLD ò PNTD

LET £ 10 keV/mm; Q = 1 LET ³ 10 keV/mm; Q = Q(L) Schematic of Passive Dosimeters New NASA-SRAG Passive Radiation Detector used for STS-114 and Expedition 12

• TLD-100 (8 samples) • TLD-300 (6 samples) • TLD-600 (2 samples) • TLD-700 (2 samples) • OSLD/Luxel (2 samples; 6 samples future flights) • CR-39 (2 samples) Detector Stack

Lexan Cover: 0.15 cm

Label (White Paper)

CR-39 (1 Sheet, Bare) 600 mm

Polycarbonate Film (1 Sheet)

CR-39 (1 Sheet, Bare) 600 mm

Polycarbonate Film (2 Sheets)

TLDs/OSLD in Lexan Holder: 0.45 cm

Service Module Monitoring Locations

US Destiny Lab to Zvezda SM = 44.5 meters US LAB Monitoring Locations Overall View of Monitoring Locations Node Dosimeter Location 2 SM-P327 (R16) Location

ISS RAM monitoring Periods for Expedition 1-10 Exposure Duration Start Date End Date (days) 5/20/1999 5/29/2000 375 5/19/2000 9/20/2000 124 9/8/2000 12/11/2000 93 12/1/2000 5/1/2001 151 4/19/2001 7/24/2001 96 7/12/2001 8/22/2001 40

8/10/2001 12/17/2001 128 12/5/2001 4/19/2002 134 4/8/2002 6/19/2002 71 6/5/2002 12/7/2002 184 11/24/2002 5/4/2003 160 10/18/2003 4/30/2004 195 4/19/2004 10/24/2004 188 10/14/2004 4/24/2005 192 Passive Monitoring Summary

• Since launch of ISS in 1998 there have been 14 separate passive monitoring periods

• The average length of monitoring periods is 152 days. ~2100 days of continuous monitoring.

• There are 17 permanent monitoring locations covering 30 meters of habitable volume – Monitoring locations are only separated by a few meters ISS Dose Rate Summary: TLD-100

350 Unity Node Location 2 SM-P442 SM-P327 300 US LAB Location 1

250 y a d / y

G TEPC locations m 200

150

100 1/1/00 1/1/01 1/1/02 1/1/03 1/1/04 1/1/05 1/1/06 Monitoring Period Ending Date Airlock ISS Radiation Area Monitors U.S. Node 1 U.S. Lab Service Module Entire Vehicle 2.1

e 2.0 t a

R 1.9

e s

o 1.8 D 1.7 n i

M 1.6 / e t

a 1.5 R

e 1.4 s o 1.3 D

x 1.2 A

M 1.1 1.0 00 00 00 01 01 01 01 02 02 02 03 04 -20 20 -20 20 -20 -20 20 -20 -20 -20 -20 -20 ay ep- ec ay- Jul ug ec- pr un ec ay pr 9-M 0-S 1-D -M 24- 2-A 7-D 9-A 9-J 7-D -M 0-A - 2 - 2 - 1 - 01 -- - 2 - 1 - 1 - 1 --0 - 04 - 3 9- 0- 0- 0- 01 1- 1- 01- 2- 02 2- 03 99 00 200 00 -20 00 00 20 200 20 00 -20 y-1 y-2 p- c-2 pr l-2 g-2 ec- pr- n- v-2 ct Ma Ma -Se De 9-A -Ju Au -D -A -Ju No 8-O 20- 19- 08 01- 1 12 10- 05 08 05 24- 1 Horizontal Alignment: SMP442 Vertical Alignment: SMP442 Node 1 - No TEPC Dose SM Cyclic Data

30 370.0 -XPH+ZNN +XVV +ZLV -YVV +ZLV +XVV +ZLV +XVV +ZLV (XPOP) (LVLH) Detector Horizontal Detector Vertical (LVLH) 25 365.0 25.9 24.5 21.7 20 360.0 20.4 20.5

15.8 d a r i

l 15 355.0 l i m 13.0 11.7 11.3 11.0 13.1 12.0 10 350.0 SM P327 NODE SM STBD CQ

5 345.0

TEPC/R16 1.66 1.9 1.8 2.21 1.71 1.44 1.30

0 340.0 2/15/05 3/1/05 3/15/05 3/29/05 4/12/05 UT 4/26/05 5/10/05 5/24/05 6/7/05

Daily TEPC values > 97 % TEPC Interval Averages by Attitude Daily R-16 Values R-16 Averages By Attitude Attitude Shift or TEPC Movement Alt (Km) TEPC Ratio TEPC Daily Dose (> 97% coverage cyclic data) Current average /previous (inverse) 1.35 .81 (1.24) 30 370.0

+XVV +ZLV -YVV +ZLV +XVV +ZLV -XPH +ZNN LVLH LVLH LVLH XPOP 25 365.0

STS-114 20.8 20.9 Docked 20 360.0

17.0 15.8 15.5 16.2 16.4 s d a r

i 15 355.0 l l

i Note: Previous TEPC m 11.9 -YVV/+XVV = 12.7 1.27 (SM CQ Detector 11.0 Horizontal) 10 1.30 (SM CQ Detector Vertical) 350.0

SM STBD SM P 327 CQ 5 345.0

TEPC/R16 1.3 1.30 1.29 1.34 1.27

0 340.0 5/30/2005 6/19/2005 7/9/2005 7/29/2005 8/18/2005 9/7/2005 9/27/2005 Daily TEPC values > 98 % TEPC IntervalGMT Averages by Attitude R-16 R-16 Averages By Attitude Attitude Shift STS-114 Alt (Km) ICCHIBAN 3 Neon

400 MeV Neon - 90 Degrees - No Absorber ) 3

m 10 m / V e k

y 8x102 a d

r s

2

m 6x102 c / r e b m u 4x102 N (

x u l F

l 2x102 a i t n e r e f f i

D 20.0 40.0 60.0 80.0 100.0 Lineal Energy (keV/mm) ICCHIBAN 3 Neon 400 MeV Neon - 0 Degrees - No Absorber )

m 3000 m / V e k 2500 y a d

r s 2000 2 m c / r e

b 1500 m u N (

1000 x u l F

l a

i 500 t n e r e f f

i 0

D 10 20 30 40 50 60 70 80 Lineal Energy (keV/mm) Trapped Differential Flux Directional Comparison of Iss-Tepc 5x103 April 30 - May 3 April 25-28 ) m 3 m 4x10 / V e k r s

2 m 3 c 3x10 / r e b m u N (

x 2x103 u l F l a i t n e r

e 3 f 10 f i D

0.0 1.0 2.0 3.0 4.0 5.0 Lineal Energy (Tissue, keV/mm) GCR Differential Flux Directional Comparison of Iss-Tepc 2.0x103 April 30-May 3 1.8x103 April 25-28 )

m 3 m 1.6x10 / V e k

3

r 1.4x10 s

2

m 3 c 1.2x10 / r e b 3

m 10 u N (

x 8.0x102 u l F

l

a 2 i 6.0x10 t n e r

e 2 f 4.0x10 f i D 2.0x102

0 1 2 3 4 5 Lineal Energy (Tissue, keV/mm) Expedition 10 Combined Integral Flux 106 Lab S4 105 Lab S1 SM-P327 Node 4 10 SM STB CQ ) r s

Total 3

2 10

Dose m Total c / r 2 Equiv. e 10 Dose Q b m

(mGy) (mSv) u 1

N 10 (

x u l 0

F 10

37.19 105.5 2.82 l a r

g -1

e 10 t n I 10-2

10-3

10-4 10-2 10-1 100 101 102 103 104 Lineal Energy (Tissue, keV/mm) Expedition 10 CR-39 Simulation

• D(TLD-300) is 38.9 mGy in 192.79 days, TEPC was operated for 16.28 days – D(TLD 300) for 16.28 days = 16.28 x (38.9/192.79) = 3.28 mGy

• D(TLD-100) for 16.28 days = 16.28 x (34.92/192.79) = 2.95 mGy Heavy Ion Efficiency

1.300 TLD-300 5500A 1.200 TLD-100 slow cool 1.100 TLD100-2 hour

) t TLD-300 5500B n

e 1.000 e l s a o v i D

0.900 u d q e r E

e 0.800 s v i C l ( e d

D 0.700 / e r e s u

s o 0.600 a D e

M 0.500

0.400

0.300

0.200 1 10 100 1000 LET in Water Comparison of TLD-TEPC combination

TLD Average D(total)/ D (TEPC) D H Q efficiency D(low) (Total) (Total) (mGy) (mGy) (mGy) (mSv) 300 0.754 3.28/ 0.601 3.43 9.56 2.78 2.83

100 0.582 2.95/ 0.601 3.20 9.33 2.91 2.59

TEPC 2.79 8.88 3.17 ISS/Shuttle TEPC Comparison-GCR

GCR Differential Flux 105 ISS-TEPC 104 ) Shuttle TEPC m m / 103 V e k 2 y 10 a d

r 1 s

10 2 m c / 100 r e b

m 10-1 u N ( -2 x 10 u l F

l -3 a 10 i t n e

r -4

e 10 f f i D 10-5

10-6 10-1 100 101 102 103 104 Lineal Energy (Tissue, keV/mm) Expedition 10 Example • NCRP 142, 2002 Equation 6.2 Q derived from Tissue Equivalent Proportional Counter (TEPC) if PNTD not utilized: • SM-P327 Dose = 38.15 mGy

Q measured by TEPC = 2.82 QD H » TLD e H = 108 mSv for 193 day mission

Factors to • Depth Dose consider: • Quality Factors/Neutrons Risø TL/OSL-DA-15C/D Reader

• OSL stimulation module: 49 Nichia Green Diodes (525 nm) • Power at the sample of ~ 43mW/cm2 • Emission filter Hoya U-340 (7.5 mm thick) Preliminary STS-114 Results: CPD

) 3.5 y Luxel (Int. OSL) G Luxel (Aver. OSL Int) m (

TLD-100 (MP)

e 3.0

s TLD-300 (HTP) o

D arm

a leg 2.5 m m a G

e 2.0 v i t a l u

m 1.5

u 0 1 2 3 4 5 6 7 8 C Crew Passive Dosimeter (CPD) #

• Simplicity of OSL dot readout STS-114 Luxel Results

1.3 Luxel -----CPD#1 -----CPD#2 1.2 -----CPD#3 -----CPD#4 1.1 -----CPD#5 (arm) R

-----CPD#5 (leg) 1 o i 1.0 H -----CPD#6 t a

R 0.9

L

S 0.8 4He O 56 84Kr 40 Fe 0.7 12 28 C 20 Ar Ne Si 0.6

0.1 1 10 100 1000 LET (keV/mm in water) The bulk etch B* – the thickness removed by etching for one surface of the CR-39 plate, can be calculated by formula (m -m )T pT B= 1 2 2 (1- 2 ) 2m2 2A where m1 is the detector mass before etching, m2, the mass after etching, T2 is the detector thickness after etching, p is the detector perimeter and A is the detector surface area. . The etch rate ratio S is calculated by Somogyi’s formula (Somogyi, 1977) .

2 2 2 æ a ö é æ b ö ù S = 1+ 4ç ÷ /ê1- ç ÷ ú è 2B ø ëê è 2B ø ûú where a and b are the major and minor axes respectively. *Etching: NaOH (6.25 N, 60oC) for 48 hours, B = 27 mm LET calibration exposures for CR-39 (2004 – July 2005)

Institute Ion Energy LET

(MeV/n) (keV/μm CR-39)

NSRL (BNL) (Sept. 04) Proton 1000 0.147

O 1000 9.39

Fe 1000 99.20

HIMAC (March 05) O 400 13.75

Ne 400 21.49

Ar 650 56.08

Fe 500 130.10

Xe 290 744.98

He 150 1.54

TAMU (March 05) Proton 14, 10, 8, 6, 3 2.60, 3.43, 4.14, 5.25, 9.50

(Gev/n)

BNL (July 05) Si 0.3, 1, 3, 5, 10 49.19, 28.76, 25.73, 26.67, 28.81

Fe 3, 5, 10 88.74, 92.01, 99.37 38

STS-114 TEPC Location Results CR - 39 detectors were used for STS - 114 mission, some preliminary results were obtained using J S C C R - 39 LET calibration and is listed below:

Results Measured by TEPC and CR-39 Location: Dose Rate Dose Equivalent Rate Quality JSC-TEPC (≥ 10 keV/μm water) (≥ 10 keV/μm water) Factor (ICRP 60) (μGy/day) (μSv/day)

TEPC 24.83 278.86 11.23 CR-39 23.81 291.00 12.22 Integral spectra of dose equivalent measured by TEPC and CR-39 STS-114 TEPC Results, full LET spectrum

GCR Trapped Total Dose Dose Dose Dose Dose Dose Equivalent Quality Equivalent Quality Equivalent Quality Rate Rate Rate Rate Factor Rate Factor Rate Factor (mGy/day) (mGy/day) (mGy/day) (mSv/day) (mSv/day) (mSv/day) ICRP-60 94.502 302.276 3.20 46.975 93.240 1.98 141.477 395.516 2.80 Shuttle TEPC/Crewmember CR-39 Results

Preliminary Results of STS-114 from CR-39 Plates (≥ 10 keV/μm water, ICRP 60)

CR-39 Dose Dose Dose Dose Equivalent Q Plate Rate Equivalent Rate (mGy) (μGy/day) (mSv) (μSv/day) Near TEPC 0.3310 23.81 4.0449 291.00 12.22 Collins 0.3376 24.29 4.1659 299.71 12.34

Future Work

• Continued investigation of Optically Stimulated Luminescence (OSL) of Al2O3:C detectors, leading to use as primary low LET dosimeter • Operational Use of Plastic Nuclear Track Detectors CR-39 to determine dose equivalent at surface of the astronaut directly • STS-114 is first mission to have full complement of TLD/OSL/CR-39, analysis of track detectors, OSLD, and TLD underway