space radiation environment

1Space technology course : Space Radiation Environment and its Effects on Spacecraft Components and Systems

Space radiation environment

Space Radiation EnvironmentSpace Radiation Environment



IntroductionIntroduction

Introduction The Earth's magnetic field Charged particle motion The radiation belts

Description South Atlantic Anomaly Dynamics of the radiation belts Models

The sources of energetic particles outside the magnetosphere Solar flares Cosmic rays Magnetospheric shielding

Sensitivity of orbits to the radiations



IntroductionIntroduction

B ow choc M agnetopause

Plasm asheet

Pseudo trappingRadiation belts

Polar cap

C osm ic rays and solar eruption

Sol

ar w

ind

Onde de choc

Ceintures de Radiation

Feuillet Neutre

Magnétopause

Cosmiques et Eruption s

Cornet Polaire

Pseudo PiégeageVent

Sol

aire Injectionsg

shock



The Earth's magnetic fieldThe Earth's magnetic field

Dipolar magnetic field lines

Ngeo

Sgeo

South Atlantic Anomaly

Dipolar magnetic field tilted

and off-center with respect to Earth



The Earth's magnetic fieldThe Earth's magnetic field

70°

80°

90°

80°

76°

Earth's magnetic field, external component.

Tsyganenko 1982 model

B

L

r

Axe du dipôle Dipole axis

Magnetic coordinates



Charged particle motionCharged particle motion

F = q.V B Lorentz force

α

VF

(q,m)

B

V

α: pitch angle

• Giration motion

Larmor radius:

Cyclotron period:

Magnetic moment:

qB

mVrL

qB

mTg

2

gL T

qriS 2

csteB

mV

2

2




Beq

V

αeq

Bm

90°

αc

*

Mirror points

Loss cone

• Bounce motion

csteB

mV

2

2

eq

eqm

meq

eq

BB

B

mV

B

mV

2

2

sin

22

sin




q<0

q>0

• Drift motion

qB

mVrL




B

ElectronProton

Drift shell

1 MeV particle at L=2

Period (larmor radius)

Electron Protons

Giration 10-6 s (1km) 10-2 s (25 km)

Bounce 0.1 s 1 s

Drift 1000 s 1000 s



The radiation belts - DescriptionThe radiation belts - Description

Particle Energy Extension (Earth radii)

e- 1 keV-30 MeV 1-10Earth

p+ 1 keV-100 MeV 1-7



The radiation belts - descriptionThe radiation belts - description

Proton radiation belt Electron radiation belt



The radiation belts - descriptionThe radiation belts - description

LANL 1989-046 / 315-500 keV electron

Drift shells

12 LT 24 LT

06 LT

18 LT

GEOLocal noon Local noon



The radiation belts - The South Atlantic AnomalyThe radiation belts - The South Atlantic Anomaly

Ng

Sg

Low Earth Orbit

Radiationbelts

Polar horne

Dipole axis

SAA

[MeV-1 cm-2 s-1 sr-1]

9.4 MeV proton - 710 km - SAC-C/SPICA

[MeV-1 cm-2 s-1 sr-1]

460. keV electron - 710 km - SAC-C/SPICA



The radiation belts - Dynamics of the radiation beltsThe radiation belts - Dynamics of the radiation belts

1 9 7 6 1 9 8 0 1 9 8 4 1 9 8 8 1 9 9 2 1 9 9 6

1 0 4

1 0 3

1 0 2

1 0 1

Flu

x (p

roto

ns/

cm2 s

)2 5 0

2 0 0

1 5 0

1 0 0

5 0

F10.7L = 1 , 2 0

L = 1 , 1 8

L = 1 , 1 6

L = 1 , 1 4

2 5 0 0 0 0

3 0 0 0 0 0

3 5 0 0 0 0

4 0 0 0 0 0

4 5 0 0 0 0

5 0 0 0 0 01 . E + 0 2

1 . E + 0 3

1 . E + 0 4

1 . E + 0 5

1 . E + 0 6

1 . E + 0 7

H

H e

O

#/cm

3C

ount

s/s

D e n s i t é sa t m o s p h é r i q u e s8 0 0 k m , 0 o , 0 o

N e u t r o n sc o s m i q u e s

Atmospheric

densities

Cosmic

neutrons

Protons

Solar cycle time scale



The radiation belts - Dynamics of the radiation beltsThe radiation belts - Dynamics of the radiation belts

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1976 1981 1986 1991 1996 2001

année

flu

x (keV

-1cm

-2s-1

sr-

1) 61.24

88.74

125.5

183.71

266.22

396.86

612.37

908.3

1284.52

50-75 keV

75-105 keV

105-150 keV

150-225 keV

225-315 keV

315-500 keV

500-750 keV

750-1100 keV

1100-1500 keV

Flu

x (k

eV-1

cm

-2 s

-1 s

r-1)

Year

Electrons

Solar cycle time scale



The radiation belts - Dynamics of the radiation beltsThe radiation belts - Dynamics of the radiation beltsElectrons - Magnetic storm time scale

100 keV

12:00

00:00

18:00

06:00



The radiation belts - Dynamics of the radiation beltsThe radiation belts - Dynamics of the radiation beltsElectrons - Magnetic storm time scale

500 keV

12:00

00:00

18:00

06:00



The radiation belts - ModelsThe radiation belts - Models

[cm-2 s

-1]

[cm-2 s

-1]Static models - NASA AP8 AE8

Species Radial extend Energy Solar cycle

AE 8 Electron L=1.2-11 40 keV-7MeV MIN/MAX

AP 8 Proton L=1.15-6.6100 keV-400

MeVMIN/MAX

E > 10 MeV E > 1 MeV



The radiation belts - ModelsThe radiation belts - ModelsStatic models - NOAA PRO & POLE

Species Radial extend Energy Solar cycle

NOAAPRO

Proton 800 km> 16, 30, 80

MeVyes

POLE Electron GEO 30 keV-2 MeV yes

NOAA PRO

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

-2 -1 0 1 2 3 4 5 6 7 8

30 keV

50 keV

100 keV

150 keV

250 keV

500 keV

1000 keV

2000 keV

Year relative to solar maximum

(keV

-1 c

m-2 s

-1)

POLE



The radiation belts - ModelsThe radiation belts - ModelsDynamic models - CRRESPRO & CRRESELE

9 .7 M e V26 .3 M eV

4 .3 M e V

5 7 M e V0

2

4

6

J, L

og1

0 (/

cm2

s sr

MeV

)

1 2 3 4L p a ra m e te r

1 2 3 4

1 06

1 04

1 02

1 00

L p a ra m eter

/cm

² sec

sr

MeV 4 .3 M eV

9 .7 M eV

2 6 M eV5 7 M eV

CRRES QUIET PROTON MODEL CRRES ACTIVE PROTON MODEL

Species Radial extend Energy

CRRESPRO Proton L=1.15-5.5 1 - 100 MeV

CRRESELE Electron L=2.5-6.5 700 keV-5 MeV



The radiation belts - ModelsThe radiation belts - ModelsComments

50

100

150

200

250

300

janv-58 janv-62 janv-66 janv-70 janv-74 janv-78 janv-82 janv-86 janv-90 janv-94 janv-98

F10.7 Watt/m2/Hz

AP8

AE8

NOAAPRO

POLE

CRRESPRO

CRRESELE

ESA SEE1



Sensitivity of orbits to the radiationsSensitivity of orbits to the radiations

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

0.01 0.1 1 10 100 1000

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

0.01 0.1 1 10

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

10 100 1000

35500 km - 0 deg

20000 km - 55 deg

1400 km - 52 deg

800 km - 98 deg

800 km - 30 deg

E (MeV) E (MeV) E (MeV)

AP8 min AE8 max Feynman 80%

(MeV-1 cm-2 s-1) (MeV-1 cm-2 s-1) (MeV-1 cm-2 s-1)

space radiation environment

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