Štísová

e-mail: [email protected]
NASA Space Radiation Laboratory
Ion Species [1]
Energy
[2] (MeV/nucleon)
Maximum Intensity
[3](ions per spill)
LET [4](keV/m)
H-1
50 - 2500
6.4 x 1011
1.26 - 0.21
He-4
300
0.88 x 1010
1.413
C-12
135 - 1000
1.2 x 1010
21.21 - 8.01
O-16
100 - 1000
0.4 x 1010
47 - 14
Ne-20
300
0.10 x 1010
35.34
Si-28
94 - 1000
0.3 x 1010
151 - 44
Cl-35
500 - 1000
0.2 x 1010
80 - 64
Ti-48
150 - 1000
0.08 x 1010
265 - 108
Fe-56
100 - 1000
0.2 x 1010
494 - 150
SequentialField (Fe/H) 1000
Various
150/0.2
Solar Particle Event
Various
1.26 - 0.21
50 - 1000
Solar Particle Events (SPEs)
•Během předpokládané mise na Mars budou astronauti vystaveni ionizujícímu
záření. Zdrojem jsou GCR a SPEs.
•Velké SPEs mohou dokonce způsobit akutní efekty– simulace jedné z největších
známých SPE
•~10% pravděpodobnost, že taková SPE nastane během dvouleté mise na Mars
•Schopnost předpovídat SPEs je stále omezená
Mewaldt : Space Science Rev (2006)
Wilson et al.: NASA Tech. Paper 3668 (1997)
Materiály a metody
Ozařování
Dávkový příkon
33.3 cGy min-1 (20 Gy h-1)
1.65 cGy min-1 (1 Gy h-1)
Materiály a metody
Ozařování
Geometrie experimentu
cells
window
beam
incubator
Materiály a metody
Buňky
Primární lidské fibroblasty
Low passage number
Exponentially growing
No antibiotics
5% CO2, humidified atmosphere, 37C
Handled in presence of yellow light / dark
Metody
Clonogenic survival
Induction of neoplastic transformation
Výsledky
Vliv dávkového příkonu
Křivky přežití
X-rays
1 GeV
100 MeV
50 MeV
surviving fraction
1
0.9
0.8
0.7
0.6
0.5
0.4
-1
-1
33.3 cGy min
-1
1.65 cGy min
-1
33.3 cGy min
-1
1.65 cGy min
-1
33.3 cGy min
-1
1.65 cGy min
33.3 cGy min
-1
1.65 cGy min
0.3
0
100
200
300
0
100
Dose (cGy)
200
300
0
100
Dose (cGy)
200
300
0
100
Dose (cGy)
200
300
Dose (cGy)
Transformace
0
0
50
100
Dose (cGy)
50
100
Dose (cGy)
0.1
40
20
0 0.01
150 0
50
100
Dose (cGy)
1
80
60
0.1
40
0.1
20
00.01
150 0
0.01
50
100
Dose (cGy)
150
surviving fraction
60
1
5
80
5
20
00.01
150 0
1
100
surviving fraction
0.1
40
X-rays
induced transformants/ 10 survivors
20
60
100
surviving fraction
40
induced transformants/ 10 survivors
80
surviving fraction
60
1 GeV protons
100
1
5
80
induced transformants/ 10 survivors
100 MeV protons
5
induced transformants/ 10 survivors
50 MeV protons
100
Výsledky
Vliv LET
-1
1.65 cGy min
1
0.9
0.8
0.7
0.6
0.5
0.8
0.7
0.6
0.5
50 MeV
100 MeV
1 GeV
X-rays
0.4
0
100
50 MeV
100 MeV
1 GeV
X-rays
0.4
0.3
0.3
300 0
200
100
Dose (cGy)
300
D
33.3 cGy min
-1
1.65 cGy min
-1
1
0.9
surviving fraction
1
0.9
surviving fraction
200
Dose (cGy)
C
10 cGy to a cell nucleus
50 MeV p+……..…14 hits
100 MeV p+……...24 hits
1 GeV p+…………..80 hits
-1
1
0.9
surviving fraction
Particle fluence = 6.242 106 × D × LET-1
B
33.3 cGy min
surviving fraction
Křivky přežití
A
0.8
0.7
0.6
0.5
0.4
0
20
40
0.6
0.5
50 MeV
100 MeV
1 GeV
X-rays
0.3
60
8
0.7
0.4
50 MeV
100 MeV
1 GeV
X-rays
0.3
0.8
80
-2
Fluence (10 p cm )
0
20
40
60
8
80
-2
Fluence (10 p cm )
A
induced transformants/ 10 survivor
100
33.3 cGy min
Transformace
Particle fluence = 6.242 106 × D × LET-1
100
B
-1
1.65 cGy min
80
60
40
20
0
0
10
20
60
40
50 MeV 20
100 MeV
1 GeV
X-rays
0
30
40
50
0
10
Dose (cGy)
induced transformants/ 10 survivor
100
33.3 cGy min
40
50
100
-1
1.65 cGy min
80
60
40
20
2
4
6
60
40
50 MeV 20
100 MeV
1 GeV
X-rays
0
10 12 14
0
0
8
8
-2
Fluence (10 p cm )
-1
50 MeV
100 MeV
1 GeV
X-rays
5
80
0
30
D
5
induced transformants/ 10 survivors
20
Dose (cGy)
C
10 cGy to a cell nucleus
50 MeV p+……..…14 hits
100 MeV p+……...24 hits
1 GeV p+…………..80 hits
-1
50 MeV
100 MeV
1 GeV
X-rays
5
80
5
induced transformants/ 10 survivors
Výsledky
Vliv LET
2
4
6
8
10 12 14
8
-2
Fluence (10 p cm )
Výsledky
Protony vs. X
100
Dose (cGy)
00.01
150 0
100
Dose (cGy)
20
0 0.01
150 0
50
100
0.1
40
0.1
surviving fraction
60
surviving fraction
40
80
5
5
50
0.1
1
20
00.01
150 0
Dose (cGy)
0.01
50
Dose (cGy)
At none of the dose rates did the
transformation efficiency of X-rays
follow a positive trend of increase with
the LET of protons.
Also, the transformation efficiency of
X-rays was less dependent on dose
rate than it was for protons of all
energies.
100
150
-1
50
20
60
1
10
8
protons
6
5
0
40
80
100
(transformants/10 survivors) cGy
0
0.1
X-rays
1
induced transformants/ 10 survivors
20
60
100
surviving fraction
40
induced transformants/ 10 survivors
80
surviving fraction
60
1 GeV protons
100
1
5
80
induced transformants/ 10 survivors
100 MeV protons
5
induced transformants/ 10 survivors
50 MeV protons
100
4
X
2
0
0
1
2
-1
LET (keV m )
Poděkování
NASA a Department od Energy za financování
Vedoucí mé práce Betsy M. Sutherland ( †7.10. 2010)
Kolegům z laboratoře
Acknowledgements
This research was supported by grants from the Human Research Program of the
Exploration Systems Mission Directorate of the NASA (NNJ07HC73I) and the Low
Radiation Dose Program of the U.S. Department of Energy (BO-089) to Betsy M.
Sutherland.
We thank Drs. Adam Rusek, Michael Sivertz, and I-Hung Chiang from the NSRL for
dosimetry and development of the low fluence beam.
We acknowledge Drs. Deborah Keszenman, Mamta Naidu, Stefan Tafrov, and Mr.
James Jardine for supporting our experiments.
Thank you for your attention!