geant4 simulations of the columbus/iss radiation environment
DESCRIPTION
D E S I R E Dose Estimation by Simulation of the ISS Radiation Environment http://www.particle.kth.se/desire/. Geant4 simulations of the Columbus/ISS radiation environment. - PowerPoint PPT PresentationTRANSCRIPT
D E S I R EDose Estimation by Simulation of the ISS Radiation Environment
http://www.particle.kth.se/desire/
Geant4 simulations ofthe Columbus/ISS radiation environment
T. Ersmark1, P. Carlson1, E. Daly2, C. Fuglesang3, I. Gudowska4, B. Lund-Jensen1,R. Nartallo2, P. Nieminen2, M. Pearce1, G. Santin2, N. Sobolevsky5
1Royal Institute of Technology (KTH) (Stockholm)2ESA-ESTEC (Noordwijk)
3EAC/JSC (Cologne/Houston)4Karolinska Institutet (Stockholm)
5Institute for Nuclear Research (Moscow)
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 2/19
Outline
1. The DESIRE project2. Geant4 physics validation studies3. Columbus and ISS geometries 4. Radiation environment models5. Simulation results6. Conclusions and future
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 3/19
The DESIRE project
• ”Dose Estimation by Simulation of the ISS Radiation Environment”• Aimed at accurate calculations of the radiation flux and doses to
astronauts inside the European ISS laboratory Columbus.• Utilizes Geant4 for radiation transport.• Funded by ESA (15613/NL/LvH) and SNSB.
1. Validation and comparisons of Geant4 physics models to…– Experiments– NASA BRYN-/HZETRN programs– SHIELD-HIT Monte Carlo program
2. Implementation of Columbus and ISS geometries in Geant4.3. Evaluation of incident radiation environment models.4. Full simulations of particle fluxes and doses inside Columbus.
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 4/19
Geant4 physics validation studies
• Incident protons with energies 10-1000 MeV.– Neutron production– Energy deposition– Proton penetration– Water, Beryllium, Carbon,
Aluminum, Iron, Uranium• Comparisons to Los Alamos
experimental data (Meier,Nucl. Sci. Eng. 102 and 104),SHIELD-HIT, BRYNTRN.
• Published in IEEE Trans. Nucl. Sci. 51,1378 (2004).
Summary: Energy deposition/proton penetration ok. Secondary neutron production ok after release of cascade models (since 2003).
113 MeV p on 4 cm Al 256 MeV p on 12 cm Al
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 5/19
Columbus and ISSgeometries• “Columbus1”
– Simple cylinder-like geometry– 10 volumes; MDPS1/2/3 + hull– 4200 kg
• “Columbus3”– Detailed geometry– 800 volumes– 16750 kg
• ISS– 350-400 volumes– 352 tons (369 tons)
...so 4 combinations
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 6/19
The ISS Geant4 geometry
Geant4
JSC/SEMDA spec.
Hull ...
Interior ...
Cabin ...
... (CAM)
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 7/19
The “Columbus3” Geant4 geometry
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 8/19
Radiation environment models
• Studied incident radiation fields– Trapped protons (isotropic and anisotropic)– GCR protons– SPE protons– (Cosmic ray albedo neutrons)– (Trapped electrons)
• Other radiation fields– GCR ions– Solar ions
• 51.6 330, 380, 430 km orbit
• Web interfaces to models– SPENVIS (”SPV”) (http://www.spenvis.oma.be/spenvis/)– CREME96 (”C96”) (https://creme96.nrl.navy.mil)– SIREST (”SRS”) (http://sirest.larc.nasa.gov)
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 9/19
Incident spectra
Incident particle spectra at 380 km and solar min
• Belt protons
• GCR protons
• SPE protons
• CR albedo neutrons
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
SPV AP8SPV PSB97SPV CRRESPRO, maxC96 GCR pSRS GCR pC96 SPE p (worst day)C96 SPE p (worst week)SRS albedo neutrons
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 10/19
Belt proton altitude dependence and anisotropy
Incident proton spectra at 330 km, 380 km, 430 km
• Solar minimum/maximum
• Anisotropy; spectra for protons coming from port and startboard-backward (at solar-minimum and 380 km)
Energy (MeV)
-110 1 10 210 310
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-110 1 10 210 310
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-610
-510
-410
-310
-210
-110
1
10
210
310 330 km, min330 km, max380 km, min380 km, max430 km, min430 km, maxUP (stb-bwd)UP (port)VF1 (stb-bwd)VF1 (port)
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 11/19
Simulation results
• Spectra of particles enteringColumbus
• Doses at 10 mm depthin ICRU sphere– Statistics...
• 380 km andsolar minimumunless noted
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 12/19
Belt protons
Incident belt (AP8-MIN) protons at 380 km. Penetrating protons and neutrons.
Belt proton doses at three altitudes for different geometry configurations.
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310Incidentp, Col1noISSn, Col1noISSp, Col1withISSn, Col1withISSp, Col3noISSn, Col3noISSp, Col3withISSn, Col3withISS
Col1noISS Col1withISS Col3noISS Col3withISSCol1noISS Col1withISS Col3noISS Col3withISS
Gy/
d)
Dos
e ra
te (
0
100
200
300
400
500
600
700
800
900
1000
Col1noISS Col1withISS Col3noISS Col3withISSCol1noISS Col1withISS Col3noISS Col3withISS
Gy/
d)
Dos
e ra
te (
0
100
200
300
400
500
600
700
800
900
1000
330 km altitude380 km altitude430 km altitude
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 13/19
On-going study ofbelt proton anisotropy
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310 Incident averageIncident stb-bwdIncident portp, stb-bwdp, port
Spectra for protons coming from
• port
• startboard-backward
SPENVIS AP8
Anisotropy model ”UP” (Badhwar/Konradi)
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 14/19
Cosmic ray protons
Penetrating primary/secondary protons and secondary neutrons due to incident cosmic ray protons (CREME96-min, 380 km)
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310Incidentp, Col1noISSn, Col1noISSp, Col1withISSn, Col1withISSp, Col3noISSn, Col3noISSp, Col3withISSn, Col3withISS
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 15/19
Cosmic ray protons; Col3withISS
Spectra of various particle species entering Columbus in the ”Col3withISS” geometry
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310IncidentProtonsNeutronsPhotonsLeptonsMesons
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 16/19
Cosmic ray proton doses
Col1noISS Col1withISS Col3noISS Col3withISSCol1noISS Col1withISS Col3noISS Col3withISS
Gy/
d)
Dos
e ra
te (
0
10
20
30
40
50
60
70
80
90
100
Col1noISS Col1withISS Col3noISS Col3withISSCol1noISS Col1withISS Col3noISS Col3withISS
Gy/
d)
Dos
e ra
te (
0
10
20
30
40
50
60
70
80
90
100
AllProtonsNeutronsPhotonsLeptonsMesonsIons
Dose rates in ICRU sphere due to incident cosmic ray protons;itemized by geometry model and particle type at surface of sphere
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 17/19
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310Incidentp, Col1noISSn, Col1noISSp, Col1withISSn, Col1withISSp, Col3noISSn, Col3noISSp, Col3withISSn, Col3withISS
SPE protons & albedo neutrons
Col1noISSCol1withISS
Col3noISSCol3withISS
Col1noISSCol1withISS
Col3noISSCol3withISS
Dos
e ra
te (m
Gy/
d)
0
2
4
6
8
10
12
14
Col1noISSCol1withISS
Col3noISSCol3withISS
Col1noISSCol1withISS
Col3noISSCol3withISS
Dos
e ra
te (m
Gy/
d)
0
2
4
6
8
10
12
14
SPE particle spectra and resulting doses Albedo neutron spectra and secondary protons
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310Incidentp, Col1noISSn, Col1noISSp, Col1withISSn, Col1withISSp, Col3noISSn, Col3noISSp, Col3withISSn, Col3withISS
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 18/19
Modell comparisons; Col3withISS
Belt p (AP8) Belt p (PSB97) GCR p (C96) GCR p (SRS) Albedo nBelt p (AP8) Belt p (PSB97) GCR p (C96) GCR p (SRS) Albedo n
Gy/
d)
Dos
e ra
te (
0
100
200
300
400
500
600
Belt p (AP8) Belt p (PSB97) GCR p (C96) GCR p (SRS) Albedo nBelt p (AP8) Belt p (PSB97) GCR p (C96) GCR p (SRS) Albedo n
Gy/
d)
Dos
e ra
te (
0
100
200
300
400
500
600 • Belt protons: 135 vs. 520 Gy/d (!)
• CR protons: 60 vs. 115 Gy/d
• Albedo neutrons unimportant (several previous studies)
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
Energy (MeV)
-210 -110 1 10 210 310 410 510
)-1
s-1
sr
-2 c
m-1
Flux
(MeV
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
SPV AP8SPV PSB97SPV CRRESPRO, maxC96 GCR pSRS GCR pC96 SPE p (worst day)C96 SPE p (worst week)SRS albedo neutrons
SPENVIS and Geant4 Workshop, Leuven, 051006, Tore Ersmark (KTH) 19/19
Conclusions and future
• A detailed model of Columbus and ISS (14A) has been implemented as Geant4 geometries.
• Dose rates has been calculated for standard incident radiation field models– Belt protons (AP8-MIN): 135 Gy/d– Cosmic ray protons (CREME96, min): 60 Gy/d– Cosmic ray albedo neutrons (SIREST): 0.5 Gy/d
• Study of the influence of belt proton anisotropy in progress.
GCR- and solar ions will be studied the next few months.