ISS Measurements at Solar Minimum (2008-2010) - Wrmiss.org

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ISS Measurements at Solar Minimum (2008-2010) - Wrmiss.org

Why Measure?Probability??? ?? ??STS-116 LaunchEVA 1 ~Ingress EVA 2 ~4hrs ETEgress


ISS Results: Expd. 20-2J/A RadiationDosimetry Report DataDosimeter/LocationSM-P327/Overhead, forwardof treadmillSM-P242/Inside Port SM CQoutboardwall aftupper cornerLAB1_TESS/Temporary SleepStation(07/15/09-04/20/10)TEPC RAM(SM-P327; COL1A3NOD2P3; JPM1FD3)DosimeterTypeMeasuredDose(mGy)Low-LETDose(mGy)TLD-100 49.65 ± 0.97 44.74 ± 1.01High-LETDose(mGy)Total Dose(mGy)DoseEquivalent(mSv)QualityFactor53.51 ± 1.12 148.50 ± 5.88 2.78 ± 0.11TLD-300 50.66 ± 0.41 43.29 ± 0.58 8.77 ± 0.49 52.07 ± 0.76 147.05 ± 5.82 2.82 ± 0.11Luxel 300s 49.78 ± 1.10 45.00 ± 1.13 53.77 ± 1.23 148.76 ± 5.90 2.77 ± 0.11TLD-100 62.81 ± 1.23 56.51 ± 1.2566.45 ± 1.32 176.46 ± 5.26 2.66 ± 0.08TLD-300 63.09 ± 0.89 55.06 ± 0.96 9.94 ± 0.42 65.00 ± 1.05 175.02 ± 5.20 2.69 ± 0.08Luxel 300s 60.36 ± 1.09 55.20 ± 1.11 65.15 ± 1.19 175.16 ± 5.23 2.69 ± 0.08TLD-100 50.82 ± 1.13 45.38 ± 1.1754.96 ± 1.28 152.75 ± 5.88 2.78 ± 0.11TLD-300 53.03 ± 0.95 44.86 ± 1.05 9.58 ± 0.51 54.44 ± 1.17 152.23 ± 5.86 2.80 ± 0.11Luxel 300s 51.29 ± 0.90 46.00 ± 0.94 55.58 ± 1.07 153.37 ± 5.84 2.76 ± 0.11TLD-100 43.43 ± 0.76 38.59 ± 0.8147.00 ± 0.95 132.52 ± 5.58 2.82 ± 0.12TLD-300 45.17 ± 0.61 37.92 ± 0.74 8.41 ± 0.49 46.32 ± 0.89 131.85 ± 5.57 2.85 ± 0.12Luxel 300s 45.93 ± 0.75 41.23 ± 0.80 49.64 ± 0.94 135.16 ± 5.57 2.72 ± 0.11


Radiation QuantitiesRadiation QuantitiesISS Expd. 18 & 20 RAM Dose Eq and Q140012001000800600SM-P327SM-P442ISS Expedition 18/ULF2LAB-TESSTEPC140012001000800600SM-P327SM-P242ISS Expedition 20/2J/ALAB-TESSTEPC4004002002003321Measured Dose (Gy/d)Dose Equivalent (Sv/d)Quality FactorRAM Locations21Measured Dose (Gy/d)Dose Equivalent (Sv/d)Quality FactorRAM Locations


Measured Dose Gy/day)Measured Dose Gy/day)ISS Expd. 16, 18 & 20 RAM Dose RatesNode 1 & Airlock400360ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 kmISS 16-17/1J/A (03/11/08 - 11/30/08); Altitude = 353.2 km400360ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 kmISS 16-17/1J/A (03/11/08 - 11/30/08); Altitude = 353.2 km320NOD1P4_03320280280A/L1_AD3240NOD1OP2CPD Dose240AL1_OF3CPD Dose200NOD1S1_02200160160120120Node 1 RAMsAirlock RAMs


Measured Dose Gy/day)Measured Dose Gy/day)ISS Expd. 16, 18 & 20 RAM Dose RatesService Module & US Lab440400ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 kmISS 16-17/1J/A (03/11/08 - 11/30/08); Altitude = 353.2 km440400ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 kmISS 16-17/1J/A (03/11/08 - 11/30/08); Altitude = 353.2 km360SM-P442360LAB1-D3320SM-P242320280SM-W14280240SM-P327SM-P307CPD Dose240CPD Dose200200160SM-P339160LAB1-OS6LAB1-PD2LAB1-OS0TESSCHeCS Rack120120Service Module RAMsUS Lab RAMs


Measured Dose Gy/day)Measured Dose Gy/day)ISS Expd. 16, 18 & 20 RAM Dose RatesNode 2 & JAXA Kibo Module320ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 kmISS 16-17/1J/A (03/11/08 - 11/30/08); Altitude = 353.2 km320ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 km280280JPM1F8_OVHD240CPD Dose240JPM1FD4CPD Dose200200160NOD2S5_CQNOD2P5_CQNOD2OP2160120120Node 2 RAMsJAXA Kibo Module (JPM) RAMs


Measured Dose Gy/day)ISS Expd. 16, 18 & 20 RAM Dose RatesESA Columbus Module360320ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 kmISS 16-17/1J/A (03/11/08 - 11/30/08); Altitude = 353.2 km280240CPD Dose200160COL_EPMCOL_EDR12080ESA Columbus RAMsDOSIS_Det 5ISS RAM


Measured Dose Gy/day)ISS Expd. 16, 18 & 20 RAM Dose RatesESA Columbus Module360320ISS 20/2J/A (07/15/09 - 02/22/10); Altitude = 351.1 kmISS 18/ULF2 (11/15/08 - 07/31/09); Altitude = 358.5 kmISS 16-17/1J/A (03/11/08 - 11/30/08); Altitude = 353.2 km280240200DOSIS-1-Det 5CPD Dose160COL_EPMCOL_EDR12080ESA Columbus RAMsDOSIS_Det 5ISS RAM


Measured Dose (Gy/day)DOSIS 1 Results (07/15/09 -11/27/09)ESA Columbus Module350300Luxel (300s)TLD-100 (MP)TLD-300 (HT)Luxel 300s174 – 250 µGy/d250200150100TLD-100174 – 249 µGy/d5001234 5 6 7 8DOSIS 1 Box910XTLD-300181 – 272 µGy/d


Measured Dose Gy/day)DOSIS 1 Results (07/15/09 -11/27/09)ESA Columbus Module360320280240200DOSIS 1 (07/15/09 - 11/27/09)2J/A (07/15/09 - 02/22/10)CPD DoseDOSIS-1(07/15/09-11/27/09)MIN 178 ± 4 µGy/dMAX 257 ± 3 µGy/dDet #5 (EPM location)160EPMEDR189 ± 2 µGy/d120801234 5 6 7 8 9DOSIS 1 Box10XISS RAMs 20/2J/A(07/15/09-02/22/10)EPM 200 ± 4 µGy/dEDR 192 ± 5 µGy/d


Quality FactorQuality FactorISS CPDs/RAMs vs. TEPC Quality Factors3.53.53.03.02.52.52.02.01.51.51.01.00.50.0ISS CPDs Combined OSL/CR-39ISS TEPC Total0 2 4 6 8 10 12 14 160.50.0ISS RAMs Combined OSL/CR-39ISS TEPC Total0 2 4 6ISS flights (2008-present)ISS flights (2008-present)ISS CPDs (all flights)• Q(CPD) is 13 % higher than Q(TEPC)• ratio of Q(CPD)/Q(TEPC) per flightvaries between 3% to 21%ISS RAMs (all flights)• Q(RAM) is 17 % higher than Q(TEPC)• ratio of Q(RAM)/Q(TEPC) per flightvaries between 13% to 22%


Quality FactorShuttle CPDs vs. TEPC Quality Factors3.53.02.52.01.51.00.50.0Shuttle CPDs Combined OSL/CR-39Shuttle TEPC Total0 2 4 6 8 10 12 14 16STS flights (2006-present)Shuttle CPDs (all flights)• Q(CPD) is 1% higher than Q TEPC• ratio of Q(CPD)/Q(TEPC) per flight iswithin error bars


10/19/2010 NASA-JSC-SRAG/USRA21


Radiation measured without (^) and with fading (*) correctionfor CR-39 sensitivity (values include background)MissionExposureAbsorbed DoseDose Equi. (ICRP60)Q(Time)Position(≥10keV/µm water)(≥ 10 keV/µm water)Factor(Days) (mGy) (mSv)P129.90^/ 36.94*270.97^/ 437.00*9.06^/ 11.83*Eye14.94 / 21.60176.59 / 274.8211.82 / 12.72Matroshka-1Stomach14.96 / 18.89156.95 / 246.1310.49 / 13.03(616)R113.90 / 17.93148.74 / 217.3110.70 / 12.12R213.85 / 17.55135.29 / 215.049.77 / 12.25P110.86 / 12.90121.10 / 150.6611.15 / 11.68Matroshka-2Eye9.13 / 10.99106.88 / 134.4811.71 / 12.24(367)Stomach8.40 / 9.6696.23 / 118.8211.46 / 12.30R211.23 / 12.97123.85 / 152.1611.03 / 11.73Expedition 12(190)TEPCTESSSMP3275.31 / 6.194.92 / 6.225.31 / 6.8360.06 / 69.0359.21 / 68.8968.98 / 78.4811.32 / 11.1512.04 / 11.0812.98 / 11.49SMP4427.99 / 10.5989.05 / 105.6111.14 / 9.97TEPC4.90 / 6.2365.33 / 74.2013.33 / 11.91Expedition 13TESS4.55 / 6.1864.09 / 73.3914.09 / 11.88(183)SMP4427.98 / 9.3194.90 / 109.9511.89 / 11.8110/19/2010 NASA-JSC-SRAG/USRA 22


A comparison of radiation quantities measured with JSC-TEPC and CR-39(Fading correction applied to CR-39, ICRP60)AbsorbedDose EquivalentQSpace MissionDose(TEPC / CR-39)Factor(TEPC / CR-39)(TEPC / CR-39)(µGy/d)(µSv/d)Expedition 12 31.70 / 31.39 346.56 / 348.18 10.93 / 11.09Expedition 13 31.31 / 30.54 356.58 / 359.97 11.39 / 11.79Matroshka-2 (R2) ~ 34* / 33.08 ~ 390* / 388.39 11.47* / 11.74* Not the exactly location and exposure time period as Matroshka-2.10/19/2010 NASA-JSC-SRAG/USRA 23


Radiation Quantities Combined from TL/OSL & CR-39Table: Radiation Quantities Combined(ICRP 60, combined at 10 keV/µm water)DetectorTL/OSLDose TL/OSLDose CR-39TotalTotal DoseQLocationTypeLow LET(Q=1)High LET(Q>10)DoseEquivalentAll LET(mGy)(mGy)(mGy)(mSv)ISS-1JAEDR(265d)TLD-100TLD-300OSLD-300sOSLD-3s45.91 ± 0.7842.45 ± 1.8648.41 ± 0.6449.92 ± 1.049.79 ± 0.3955.70 ± 0.8752.24 ± 1.9058.21 ± 0.7559.71 ± 1.11159.96 ± 4.63156.50 ± 4.93162.46 ± 4.61163.97 ± 4.682.87 ± 0.083.00 ± 0.092.79 ± 0.082.75 ± 0.08ISS-ULF2EPM(259d)TLD-100TLD-300OSLD-300sOSL-3s47.96 ± 1.1346.23 ± 1.2144.70 ± 1.5243.50 ± 2.8510.74 ± 0.6258.70 ± 1.2956.97 ± 1.3655.45 ± 1.6454.24 ± 2.92171.75 ± 7.22170.02 ± 7.24168.49 ± 7.29167.29 ± 7.682.93 ± 0.122.98 ± 0.133.04 ± 0.133.08 ± 0.14DOSISTLD-10024.00 ± 0.5029.08 ± 0.5777.80 ± 3.052.68 ± 0.10JSC-11(x)*(135d)TLD-300OSLD-300s24.36 ± 0.4524.76 ± 0.695.08 ± 0.2729.44 ± 0.5229.84 ± 0.7578.16 ± 3.0478.56 ± 3.092.65 ± 0.102.63 ± 0.10* TL/OSL data available only.10/19/2010 NASA-JSC-SRAG/USRA24


D10/19/2010 NASA-JSC-SRAG/USRA25


10/19/2010 NASA-JSC-SRAG/USRA26


10/19/2010 NASA-JSC-SRAG/USRA27


Radiation measured with TEPC and CR-39(STS-125 & 126, ≥ 10 keV/µm, ICRP 60)DetectorAbsorbedDoseDoseEquivalentQFactor(mGy/d)(mSv/d)STS-125CR-39: PRD-1 0.170±0.014 1.934±0.156 11.34±0.92CR-39: PRD-2JSC-TEPCCR-39 with TEPCSTS-1260.364±0.0230.195±0.0020.182±0.0164.033±0.2501.721±0.0181.835±0.16311.09±0.698.84±0.0910.08±0.89CR-39: PRD-1 0.031±0.002 0.357±0.017 11.70±0.57CR-39: PRD-2 0.044±0.003 0.498±0.038 11.43±0.8810/19/2010 NASA-JSC-SRAG/USRA28


Table: Radiation combined from TL/OSL and CR-39(STS-125, ICRP 60, combined at 10 keV/µm water)Dose TL/OSLDose CR-39TotalTotal DoseQDetectorTLD/OSLDLow LET(Q=1)High LET(Q>10)DoseEquivalentAll LETType(mGy)(mGy)(mGy)(mSv)TLD-10018.26 ± 0.3620.45 ± 0.4143.20 ± 2.052.11 ± 0.10PRD-1TLD-30017.75 ± 0.4719.95 ± 0.5142.70 ± 2.072.14 ± 0.10OSLD-300s18.76 ± 0.482.20 ± 0.1820.96 ± 0.5143.71 ± 2.072.09 ± 0.10OSL-3s19.94 ± 0.7522.14 ± 0.7744.89 ± 2.152.03 ± 0.09TLD-10052.38 ± 0.7957.06 ± 0.84104.40 ± 3.321.83 ± 0.06TLD-30052.61 ± 1.1457.30 ± 1.17104.63 ± 3.421.83 ± 0.06PRD-2OSLD-300s52.18 ± 1.554.69 ± 0.2956.87 ± 1.58104.20 ± 3.581.83 ± 0.06OSLD-3s55.60 ± 1.9760.30 ± 1.99107.63 ± 3.781.79 ± 0.0610/19/2010 NASA-JSC-SRAG/USRA29


Next• ISS-RAD– ~Q3 2013• Crew active dosimetry– 2 digit dimensions (mm)– 10d on battery– Z, E spectra/discrimination• Purpose is direct risk estimation• Mars/NEO thoughts– Collaborations?• JSC CR-39– NASA current uncertainty– Operational synergy between console ops and laboratory needs– Systematics to TEPC10/19/2010 NASA-JSC-SRAG/USRA30


Acknowledgements• SRAG Team at NASA/JSC• NASA/JSC ISS Flight Hardware Integration Teams• DOSIS 1 Team, especially Drs Guenther Reitz and Thomas Berger at DLR


Thank you


For the isotropic radiation field, the differential fluence F is:FThe differential absorbed dose (Gy) is then4(2Acos1.61029dNdLET LET FThe differential dose equivalent is obtained as Dose×Q, where Qis the quality factor recommended by ICRP-60.The integral spectrum is generated by summing the differentialspectrum from high LET to low LET.The average quality factor is calculated byQ (≥ LET) = integral dose equivalent (≥ LET) / integral dose (≥ LET)The relationship of LET∞ in water and LET200 in CR-39 is:Log (LET ∞ water) = 0.1689 + 0.984log (LET 200 CR-39)cut)110/19/2010 NASA-JSC-SRAG/USRA 33


ISS Expd. 16/1J/A(03/11/08-11/30/08)ISS Expd. 20/2J/A(07/15/09 - 02/22/10)DOSIS 1-Det 5 EPM(07/15/09 - 11/27/09)DOSIS 1 Data ComparisonESA Columbus ModuleDetectorEPM Measured Dose(µGy/day )EDR Measured Dose(µGy/day )JSC-TLD100 200.6 ± 2.8 194.4 ± 2.8JSC-TLD600 201.7 ± 5.9 208.7 ± 5.1JSC-TLD700 207.1 ± 4.0 200.1 ± 3.6DLR-TLD600 214.2 ± 0.4 217.7 ± 0.3DLR-TLD700 208.2 ± 0.6 203.4 ± 2.5JSC-TLD100 205.1 ± 3.6 193.9 ± 5.3JSC-TLD300 200.7 ± 6.0 194.6 ± 5.0JSC-TLD700 190.4 ± 2.0 201.0 ± 2.4JSC-TLD100 183.9 ± 2.3JSC-TLD300 198.2 ± 1.2DLR-TLD300 236.8DLR-TLD600 245.4DLR-TLD700 231.5


3. Exposure of DOSIS-IExposure Dates:July 2009 - May 2010, 135 d;Inclination 51.6 o ; near solar minimum.Exposure Location:EPM (European Physiology Module)JSC-SRAG passive dosimeters were exposedalso in EPM (ISS-ULF2, Nov. 08 - July 09, 259 d).Results from ISS-ULF2-EPM and DOSIS-I shouldhave good comparison.10/19/2010 NASA-JSC-SRAG/USRA 35


4. CR-39 LET Spectrum Method4-1. The characteristics of the LET spectrummethod used in JSC-SRAG:• Chemical etch (bulk etch


4-2. Procedures of LET SpectrumMethod Using CR-39 PNTDs• Radiation exposure;• Detector recovery;• Chemical etch of detectors;• Data scan (manually) and analysis;• LET calibration;• Correction for the fading of the CR-39sensitivity (for long term exposure);• LET spectrum generating.10/19/2010 NASA-JSC-SRAG/USRA 37


4-3. LET Spectrum GeneratingFor the isotropic radiation field, the differential fluence F is:F(2AcosThe differential absorbed dose (Gy) is then2cut)1dNdLET41.6109 LET FThe differential dose equivalent is obtained as Dose×Q, where Qis the quality factor recommended by ICRP-60.The integral spectrum is generated by summing the differentialspectrum from high LET to low LET.The average quality factor is calculated byQ (≥ LET) = integral dose equivalent (≥ LET) / integral dose (≥ LET)The relationship of LET ∞ in water and LET 200 in CR-39 is:Log (LET ∞ water) = 0.1689 + 0.984log (LET 200 CR-39)10/19/2010 NASA-JSC-SRAG/USRA 38


5. Correction for CR-39 Sensitivity Fading• When charged particles pass through CR-39,they break the molecular bonds of the materialto form damage trails with high ionization.• Environmental oxygen around CR-39 detectorstends to combine with ions and radicals,preventing their recombination and changingthe sensitivity of the CR-39.• Higher temperature makes the recombinationof the ionization easier and faster.• The longer the time between the momentparticle passing through the detector and theetch of the detector, the more fading.10/19/2010 NASA-JSC-SRAG/USRA 39


Sensitivity fading of CR-39 detectors was observed forall Expedition space missions (>~ 180d) and Matroshkaexperiments (>~ 1y). Due to fading the LET values andthe radiation quantities were small.JSC-SRAG successfully developed a method to correctsensitivity fading of CR-39 with exposure time longerthan several months. The method is the “internal LETcalibration using GCR iron peak at ~ 1 GeV/n”.The effect of the correction is to make the GCR iron peakat ~137 keV/μm water. Using data from Expedition andMatroshka, a formula was found as:Sc=So/[1–(2.44243×T+9.53942)×10 -3 ]where So and Sc is the etch rate ratio without and withsensitivity correction, T is the exposure time in month.10/19/2010 NASA-JSC-SRAG/USRA 40


To combine the dose and dose equivalent measured byTLDs/OSLDs and by CR-39 PNTDs, the average value ofdetection efficiency for TLDs/OSLDs above 10 keV/μmwater is needed and can be calculated by the formula:LETave10keVmax/ mD(CR( LET) Didose(LET 39, 10keVm)where Didose(LET) is the differential dose measured bythe CR-39 detectors, D(CR-39, ≥10 keV/µm water) is theintegral absorbed dose measured by CR-39 and ε(LET) isthe detection efficiency of the TLDs/OSLDs.The formula indicates that the higher the detectionefficiency, the higher the average detection efficiency.10/19/2010 NASA-JSC-SRAG/USRA 41/)


The low LET dose is thenD low =D(TLDs/OSLDs) – ε ave D(CR-39, ≥10 keV/µm water)The total dose isD total =D low + D(CR-39, ≥10 keV/µm water)The total dose equivalent is given by:H total =H low (TLDs/OSLDs, Q=1)+H(CR-39, ≥10 keV/µm water)where H low (TLDs/OSLDs, Q=1) is the dose equivalent forlow LET measured by TLDs and OSLDs and the qualityfactor is 1, H(CR-39) is the dose equivalent (≥ 10 keV/µmwater) measured by CR-39 PNTDs.The above expression is essentially the same as thatrecommended by NCRP (NCRP report 142, 2002).The total average quality factor Q is thenQ = H total / D total10/19/2010 NASA-JSC-SRAG/USRA 42

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