Dr. Scott R. Messenger SFA, Inc. ([email protected])

Dr. Scott R. MessengerSFA, Inc.

([email protected])

SPENVIS & GEANT4 workshop Faculty Club

Leuven, Belgium3 - 7 October 2005

Displacement Damage Dose Approach For Determining Solar Cell Degradation In

Space With Spenvis Implementation

• Introduction• Space Solar Cell Degradation Calculations

– NASA JPL Equivalent Fluence Method– NRL Displacement Damage Dose (Dd) Method

• Nonionizing Energy Loss (NIEL)

– Comparisons

• SPENVIS Implementation– MULASSIS is the key

• Notes• Future Work

Outline

S. Messenger, SPENVIS Workshop 2005

• Omnidirectional, isotropic, energy spectrum in space

• Unidirectional, normally incident, monoenergetic irradiation of bare solar cells on the ground

p+

COVERGLASS

SUBSTRATE

ACTIVE CELL

PANEL

p+

e-

e-

e-

e-

e-

p+

p+

p+

p+

p+

p+

COVERGLASS

SUBSTRATE

ACTIVE CELL

PANEL

p+

e-

e-

e-

e-

e-

p+

p+

p+

p+

p+

COVERGLASS

SUBSTRATE

ACTIVE CELL

PANEL

p+

e-

e-

e-

e-

e-

p+

p+

p+

p+

p+

protons

electrons

The Problem


*Planar, slab geometry

Pmax Degradation Curves for GaAs/Ge Solar Cells (JPL, 1991)

108

109

1010

1011

1012

1013

1014

1015

1016

1017

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0N

orm

aliz

ed M

axim

um

Po

wer 1 Sun, AMO

GaAs/Ge

Particle Fluence (cm-2

)

Protons

Electrons0.6 MeV1 MeV2.4 MeV12 MeV

9.5 MeV3 MeV1 MeV0.5 MeV0.3 MeV0.2 MeV0.1 MeV0.05 MeV

25oC


• Equivalent Fluence Method – created by NASA Jet Propulsion Laboratory (JPL)– Can be implemented through available FORTAN programs

– Is included in the SPENVIS web-suite (and others)

– Has widespread application and over 30 years of heritage

• Displacement Damage Dose Method (Dd) – created by the US Naval Research Laboratory (NRL)– Does not have widespread application due to lack of distributed computational

tool

• Solar Array Verification and Analysis Tool (SAVANT) is available but only in beta-version (unfunded at present)

• This paper shows how the SPENVIS web-suite can be used to implement the Dd method

The Solution


JPL and NRL Methods

•NASA Jet Propulsion Laboratory (Pasadena, CA)

–Reduces mission space radiation effects to an equivalent 1 MeV electron fluence

–Read EOL power from measured 1 MeV electron curve

•US Naval Research Laboratory (Washington, DC)

–Calculate displacement damage dose, Dd, for mission

–Read EOL power from measured characteristic curve


JPL Method (Equivalent Fluence Method)

•Summarized in two publications (developed in 1980’s)

–Solar Cell Radiation Handbook, JPL Publication 82-69 (1982)

–GaAs Solar Cell Radiation Handbook, JPL Publication 96-9 (1996)

•Utilizes the concept of relative damage coefficients (RDC’s)

•Reduces all damage to a 1 MeV electron equivalent fluence and uses 1 MeV electron data to get the EOL result

•Several computer programs (FORTRAN) are available:

–EQFLUX (Si), EQGAFLUX (GaAs), and multijunction (MJ) cell

–Other programs (e.g. SPENVIS and Space Radiation) implement JPL method


Measure PV Degradation Curves (~4 electron and

~8 proton energies)

Determine Damage Coefficients for Uncovered Cells

Calculate Damage Coefficients for Isotropic Particles w/ Coverglasses of Varied

Thickness

Read Off EOL Values

Determine Incident Particle Spectrum (e.g. AP8)

JPL Equivalent Fluence Method

1 MeV Electron Degradation Curve

Calculate Equivalent 1 MeV Electron Fluence for Orbit (EQGAFLUX)


Electron Damage Coefficients

Proton Damage Coefficients

Electron and ProtonFluence Data (GaAs/Ge, 1991)


10-1 100 101 102

Electron Energy (MeV)

10-3

10-2

10-1

100

101

102

Rel

ativ

e P

max

Dam

age

Co

effi

cien

t

0 mil1 mil3 mil6 mil12 mil20 mil30 mil60 mil

Coverglass Thickness

*Relative to 1 MeV normalincidence data, w/o coverglass

Normal incidenceno coverglass

10-2 10-1 100 101 102

Proton Energy (MeV)

10-2

10-1

100

101

102

Rel

ativ

e P

max

Dam

age

Co

effi

cien

t0 mil1 mil3 mil6 mil12 mil20 mil30 mil60 mil

Coverglass Thickness

*Relative to 10 MeV proton normalincidence data, w/o coverglass

Normal incidenceno coverglass

108

109

1010

1011

1012

1013

1014

1015

1016

1017

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

No

rmal

ized

Max

imu

m P

ow

er 1 Sun, AMOGaAs/Ge


)

Protons



25oC

75% BOL


Equivalent 1 MeV Electron Fluence

2/

0

0 dsin2)0,E(RDC4

1t)RDC(E,

ppp

pppeee

e

eeelectronMeV 1 t)dE,(ERDC

dE

)(EdCt)dE,(ERDC

dE

)(Ed

cos

t)E(RR)t,,E(E 1

0

where the energy loss is determined from

R(E) is the range

(for electrons*)

where the RDCs for a coverglass thickness t is:

*for protons, another term is included to account for end-of-track effects


Initial Omnidirectional Spectrum

Equivalent 1 MeV Electron Fluence

Proton Damage Coefficients

1 MeV Electron Pmax Degradation

10-1 100 101 102 103

Proton Energy (MeV)

5000 km, circular, 600 orbit (1 year duration)

107

108

109

1010

1011

1012

1013

1014

Flu

ence

(cm

2 MeV

)-1

10-2 10-1 100 101 102

Proton Energy (MeV)

10-2

10-1

100

101

Rel

ativ

e P

max

Dam

age

Coe

ffic

ien

t

0 mil1 mil3 mil6 mil12 mil20 mil30 mil60 mil

Coverglass

*Relative to 10 MeV normalincidence data, w/o

Thickness

coverglass, based on Pmax

1014 1015 1016 1017

1 MeV Electron Fluence (e-/cm2)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Nor

mal

ized

Pm

ax D

egra

dat

ion

GaAs/Ge (JPL, 1990)

1 Sun, AM0, 25oC


0 10 20 30 40 50 60 70 80SiO2 Coverglass Thickness (mil)

1014

1015

1016

1 M

eV E

lect

ron

Flu

ence

(e- /c

m2 )

GaAs

5000 km, circular, 60o orbit (1 year duration)

JPL Model Pros/Cons

• Pros:– Heritage (developed in the 1980s)– Widely available and already incorporated into many space

radiation suites (SPENVIS, Space RadiationTM, etc.)

• Cons:– Much ground test data needed ($$)– Requires 1 MeV electron AND 10 MeV proton data– Currently available for Si (1982), GaAs/Ge (1996), MJ (1999)– Program not particularly user friendly (FORTRAN)

– Several flags need to be set– Entire calculation is technology specific (every design change

needs requalification, $$)


NRL Method (Displacement Damage Dose, Dd)

•Summarized in:–Progress in PV: Research and Applications 9, 103-121 (2001)–Appl. Phys. Lett. 71, 832 (1997)–IEEE Trans. Nucl. Sci. 44, 2169 (1997)

•RDCs calculated from the nonionizing energy loss (NIEL)

•Determines degradation curve as a function of Dd and uses this curve to get the EOL result•Particle transport through the coverglass calculated independently from RDC calculation•Computer program (SAVANT) developed by NRL, NASA GRC, and OAI (unfunded at present) – SPENVIS?


Choose Nonionizing Energy Loss (NIEL) Data

(Energy Dependence of Damage Coefficients)

Measure Characteristic Degradation Curve vs. Dd

(Dd=NIELxFluence) (2 e- and 1 p+ energy)

Read Off EOL Value

Determine Incident Particle Spectrum (e.g. AP8, AE8)

Calculate Slowed-Down Spectrum (SDS) (Shielding)

Calculate Dd for Mission (Integrate SDS with NIEL)

NRL Displacement Damage Dose Method


NonIonizing Energy Loss

NIEL= Rate at which energy is lost to nonionizing events; (UNITS=MeV/cm or MeVcm2/g)

)T( dmin

E)]d,E)L[T(,T(d

E),(dNIEL(E)

Differential scattering cross section for

displacements

Recoil energy

Lindhard partition factor


• Several calculations exist, all yielding similar results

• Notable NIEL calculations (p+, e-, , no, ions) : NRL group (NSREC, 1986-2003) Van Ginneken, 1989 NASA/JPL group (2000-2005, WINNIEL) CERN group (Huhtinen et al., 2000-2005) Akkerman and Barak, 2001 Inguimbert & Gigante (NEMO, 2005) Fischer and Thiel, U. Koln

• Especially good agreement over practical proton energies for solar cells in space (0.1-10 MeV)

NonIonizing Energy Loss


10-4 10-3 10-2 10-1 100 101 102 103

Particle Energy (MeV)

10-6

10-5

10-4

10-3

10-2

10-1

100

101

Si N

IEL

(M

eVcm

2 /g)

ProtonElectronNeutron

*Td = 21 eV

Si

NIEL for Si (w/Neutron)





(Dd = NIEL x Fluence) (1 p+ and 2 e- energies)

Read Off EOL Value






Displacement Damage Dose (Dd)Unit is MeV/g is analogous to ionizing dose Rad(Si)

1)(n

refrefd )NIEL(E

NIEL(E)NIEL(E)(E))E(D

Protons: n=1

Electrons: 1<n<2

Or, for a spectrum of particles, as that found in space,

Slowed-down differential spectra


e

1ne

ee

eeppp

p

pd dE

)MeV1(NIEL

)E(NIEL)(ENIEL

dE

)(EdR)dE(ENIEL

dE

)(EdD

•Characteristic curve is independent of particle

•Calculated NIEL gives energy dependence of damage coefficients

•4 empirically determined parameters (C,Dx,Rep,n)

Characteristic Curve

With NIEL

Measured DataNRL Displacement Damage Dose Method

108 109 1010 1011 1012

Displacement Damage Dose (MeV/g)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

No

rmal

ized

Max

imu

m P

ow

er 1 Sun, AM0T=25oC

GaAs/Ge

0.6 MeV1 MeV2.4 MeV12 MeV

Protons Electrons9.5 MeV3 MeV1 MeV0.5 MeV0.3 MeV0.2 MeV

1 MeV equiv.

Neutrons10

810

910

1010

1110

1210

1310

1410

1510

1610

170.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

No

rmal

ized

Max

imu

m P

ow

er

1 Sun, AMOGaAs/Ge


)

Protons



25oC

1 MeV equiv.

Neutrons


10-4 10-3 10-2 10-1 100 101 102 103

Particle Energy (MeV)

10-6

10-5

10-4

10-3

10-2

10-1

100

101

GaA

s N

IEL

(M

eVcm

2 /g)

ProtonElectronNeutron

*Td = 10 eV, Ga & As

GaAs





Read Off EOL Value






• Based on the Continuous Slowing Down Approximation (CSDA)• The rate of energy loss equals that due to

the total stopping power (i.e. no energy loss fluctuations, straggling)

• Particle transport governed by range data• CSDA not expected to hold for electrons of

low energy

An Analytical Calculation Implementing the Dd Approach


Analytical Proton Transport Model

10-4 10-3 10-2 10-1 100 101 102 103

Proton Energy (MeV)

107

108

109

1010

1011

1012

1013

1014

1015

1016

Dif

fere

nti

al F

luen

ce (

cm-2

MeV

-1)

30 mil

Uncovered

5000 km, Circular Orbit60 Inclination5 year mission

E'

E1E2

E3E4

E5

12 mil

3 mil

SiO2 coverglass






Read Off EOL Value






0 10 20 30 40 50SiO2 Thickness (mil)

109

1010

1011

1012

Dd (

MeV

/g) (1 Year Mission)

GaAs

5000 km, circular, 60o

108 109 1010 1011 1012


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

No

rmal

ized

Max

imu

m P

ow

er

1 Sun, AM0T=25oC

GaAs/Ge

Incident and SDS (Isotropic) NonIonizing Energy Loss

Total Mission Dose

Pmax Degradation


10-4 10-3 10-2 10-1 100 101 102 103

Proton Energy (MeV)

107

108

109

1010

1011

1012

1013

1014

1015

1016

Dif

fere

nti

al F

luen

ce (

cm-2

MeV

-1)

3 mil

30 mil

12 mil

Uncovered

SiO2 Coverglass Thickness


10-4 10-3 10-2 10-1 100 101 102 103

Proton Energy (MeV)

10-3

10-2

10-1

100

101

GaA

s N

IEL

(M

eVcm

2/g

)

Proton

*Td = 10 eV, Ga & As

GaAs


10-4 10-3 10-2 10-1 100 101 102 103

Slowed-Down Proton Energy (MeV)

0.0

0.2

0.4

0.6

0.8

1.0C

um

ula

tive

Fra

ctio

n o

f D

d

3 mil

30 mil

12 mil

GaAs


Cumulative Fraction of Dd


SAVANT Dd Analysis Code


SAVANT: Solar Array Verification and Analysis Tool (NASA, NRL, OAI)

0 10 20 30 40 50 60SiO2 Coverglass Thickness (mils)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Displacement Damage Dose (NRL) ModelEquivalent Fluence (JPL) Model

5093 km, circular, 60o orbit (1 year duration)

Nor

mal

ized

Max

imum

Pow

er D

egra

dati

onGaAs/Ge

Comparison of Results


NRL Dd Model Pros/Cons• Pros:

– Few ground test measurements needed (3)– Ground test particle energies can be conveniently chosen

– Uniform damage deposition required over active region– Shielding algorithm is independent– Allows for rapid analysis of emerging cell technologies– Allows for easy trade studies– Can combine data from different experiments– Allows for alternate radiation particles (neutrons, alphas, etc.)

• Cons:– Lack of heritage (developed in the mid-1990s)– More suited for sufficiently thin devices (~few m)– Program currently not available to general public


Why does the Dd Method work so well?


The energy dependence of the NIEL closely follows the RDCs over practical energies considered for space applications

10-2 10-1 100 101 102

Energy (MeV)

10-1

100

101

102

103

Rel

ativ

e P

max

Dam

age

Co

effi

cien

t SJ GaAs/Ge2J InGaP/GaAs/Ge3J InGaP/GaAs/GeCIGSNIEL GaAsJPL MJ RDCs SRIM MJ RDCs

Protons

*Parameters normalized to value at 10 MeV

Proton NIEL Comparison vs. RDCs


10-1 100 101 102

Energy (MeV)

10-3

10-2

10-1

100

101

102

Re

lati

ve

Pm

ax D

amag

e C

oe

ffic

ien

t Electrons

*Parameters normalized to value at 1 MeV

SJ GaAs/Ge2J InGaP/GaAs/Ge3J InGaP/GaAs/GeCIGS1 MeV Equiv. NIEL GaAs (n=1.7)1 MeV Equiv. NIEL CIGS (n=2)

Electron NIEL Comparison vs. RDCs


Effect of Low Energy Protons on Multijunction (MJ) Solar Cells


Monoenergetic, Unidirectional Irradiations

108 109 1010 1011 10120.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

30 keV50 keV70 keV100 keV150 keV250 keV380 keV1 MeV2 MeV3 MeV5 MeV

Proton Energy


Rem

ain

ing

Fac

tor

of

Pm

ax

*T. Sumita, M. Imaizumi, S. Matsuda, T. Ohshima, A. Ohi, and T. Kamiya, Proc. 19th EPVSEC, Paris, 2004.

3J InGaP2/GaAs/Ge


300 500 700 900 1100 1300 1500 1700 19000.0

0.2

0.4

0.6

0.8

1.0

Wavelength (nm)

Qu

antu

m E

ffic

ien

cy

Solid lines: Unirradiated

Dashed lines: 1x1012 p+/cm2

50 keV Protons

InGaP/GaAs/Ge

300 500 700 900 1100 1300 1500 1700 19000.0

0.2

0.4

0.6

0.8

1.0

Wavelength (nm)

Qu

antu

m E

ffic

ien

cy



100 keV Protons

InGaP/GaAs/Ge

300 500 700 900 1100 1300 1500 1700 19000.0

0.2

0.4

0.6

0.8

1.0

Wavelength (nm)

Qu

antu

m E

ffic

ien

cy



400 keV Protons

InGaP/GaAs/Ge

300 500 700 900 1100 1300 1500 1700 19000.0

0.2

0.4

0.6

0.8

1.0

Wavelength (nm)

Qu

antu

m E

ffic

ien

cy



1 MeV Protons

InGaP/GaAs/Ge

Proton-Induced QE Degradation in MJ Cells

50 keV protons

100 keV protons

400 keV protons

1 MeV protons


108 109 1010 1011 10120.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

30 keV50 keV70 keV100 keV150 keV250 keV380 keV1 MeV2 MeV3 MeV5 MeV

Proton Energy


Rem

ain

ing

Fac

tor

of

Pm

ax

Monoenergetic, Unidirectional Irradiations

• Typical ground test conditions (not space conditions)• Nonuniform vacancy distribution – Bragg Peak at end of track• Different energies can preferentially degrade one sub-junction• This effect is not seen in 1 MeV Electron irradiation

Top cell degradation

Middle cell degradation

*T. Sumita, M. Imaizumi, S. Matsuda, T. Ohshima, A. Ohi, and T. Kamiya, Proc. 19th EPVSEC, Paris, 2004.

*Results from SRIM 2003 v.26 (www.srim.org)

10-2 10-1 100 101 102 103

Depth (m)

10-1

100

101

102

Va

ca

nc

y P

rod

uc

tio

n R

ate

(#

/m

/ion

) 63.1 keV Mono, Norm251 keV Mono, Norm1 MeV Mono, Norm

GaAs GeInGaP


Spectrum, Omnidirectional Irradiation

• Representative of exposure in the space radiation environment

• The vacancy distribution profile is nearly uniform over active region

*Results from SRIM 2003 v.26 using special input file (TRIM.DAT) which specifies random incident angle and energy to simulate L2 spectrum (3 mil SiO2)

No special effects due to low energy protons apparent!

10-2 10-1 100 101 102 103

Depth (m)

10-2

10-1

100

101

102

Va

ca

nc

y P

rod

uc

tio

n R

ate

(#

/m

/ion

)

L2 Spectrum, 3 mils SiO2

GaAs GeInGaP


MJ Radiation Response Analysis Methodology

• Space radiation environment produces virtually uniform vacancy distribution throughout cell– To reproduce this with a monoenergetic, unidirectionally incident

particle, we need a fully penetrating proton (>1 MeV)

– NO LOW ENERGY PROTON IRRADIATION NECESSARY

• Total damage induced in cell (i.e. total number of vacancies) in space can be quantified in terms of Displacement Damage Dose (Dd)

– Value of Dd is calculated by integrating the product of the slowed-down spectrum and the NIEL over energy

– Validation exists for several MJ technologies

– Enables quick and inexpensive qualification of new technologies

– SPENVIS Implementation Soon!!!

1) Incident differential radiation spectra (SPENVIS)

2) Calculation of the “slowed-down” spectra after having passed through shielding (analytical, MULASSIS)

3) Calculation of the total Dd for the mission (MULASSIS)

4) Determination of the expected cell degradation (to be added, need characteristic curve info, i.e. C, Dx, n, Rep)

SPENVIS ImplementationThere are four basic components involved in this calculation:

MULASSIS is the enabling tool!


Walk Through SPENVIS –Orbit Generation


Walk Through SPENVIS –Incident Particle Spectra


Walk Through SPENVIS –Shielding (Slowed Down Spectra) and Equiv. Dd

x

x

x

x

Run

• Fluence – gives slowed down spectra

• NIEL option – performs integration with NIEL to give mission Dd (not fully operational)


5093 km, circular, 57 degree, 1 year, 12 mils SiO2/Si

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1.E+13

1.E+14

1.E+15

1.E+16

1.E+17

1.E-03 1.E-02 1.E-01 1.E+00 1.E+01

Electron Energy (MeV)

Dif

fere

nti

al S

pe

ctr

a (

e/c

m2 /M

eV

)

Incident Spectrum

Slowed-Down Spectrum (In-House Calc)

Slowed-Down Spectrum (MULASSIS)

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1.E+13

1.E+14

1.E+15

1.E+16

1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03

Proton Energy (MeV)

Dif

fere

nti

al S

pe

ctr

a (

p/c

m2 /M

eV

)

Incident Spectrum

Slowed-Down Spectra (In-House Calc)

Slowed-Down Spectrum (MULASSIS)

Calculations Made External to SPENVIS –Equivalent Value of Dd

• Slowed-down spectra exported as TXT file from MULASSIS• Read into MS Excel and integrated with NIEL to give Dd• Also calculated by in-house NRL program for comparison

Proton Dd (MeV/g) Electron Dd (MeV/g)MULASSIS 3.8E+10 5.4E+08In-House Calc 3.3E+10 6.0E+08

protonselectrons

e

ne

ee

eeppp

p

pd dE

)MeV(NIEL

)E(NIEL)(ENIEL

dE

)(EdR)dE(ENIEL

dE

)(EdD

1

1


1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1.E+13

1.E+14

1.E+15

1.E+16

1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03

Proton Energy (MeV)

Dif

fere

nti

al S

pe

ctr

a (

p/c

m2 /M

eV

)

Incident Spectra

Slowed-Down Spectra (Mathcad)

MULASSIS (10,000,000 particles)

MATHCAD RESULT Dd= 1.85E+07 MeV/gMULASSIS RESULT Dd= 1.50E+07 MeV/g

% 1.91E+01

*5093 km, circular, 57 degree, 1 year, 1000 mils Al/Si

Thick Shielding Example


Calculations Made External to SPENVIS –Solar Cell End-of-Life Power Output

x

ddmax

D

DlogC

P

)D(P11

0

108108 109 1010 1011


0.5

0.7

0.9

1.1

Nor

m P

mp

0

0.312.5101212

Emcore 3J Cells

Energy (MeV)

electron

proton C = 0.199

Dx = 1.2x109 MeV/g

n = 1.8Rep = 0.17

(c, Dx, n, Rep)

108108 109 1010 1011


0.5

0.7

0.9

1.1

Nor

m P

mp

0

0.312.5100.6112

Spectrolab EOL 3J Cells n/p cells

Energy (MeV)

electron

Data from Marvin 2000

proton

C = 0.3

Dx = 3x109 MeV/g

n = 1.6Rep = 0.3

108108 109 1010 1011


0.5

0.7

0.9

1.1

Nor

m P

mp

0

0.20.415100.611.6

Tecstar 3J Cells

Energy (MeV)

electron

proton C = 0.25

Dx = 1x109 MeV/g

n = 1.09Rep = 0.17

Independent Variables


•Mulassis agrees very well with the analytical slab geometry model for protons

•Mulassis allows for multiple interfaces and layers

•Effect of electrons usually minimal (However, MULASSIS is probably better since analytical model assumes CSDA)

•Could be extended for use with heavy ions and neutrons (NIEL is available for most cases)

•Could be used for other devices where displacement damage is an important damage mechanism (e.g. LED light output, CCD degradation, transistor gain, etc.)

Notes


•Continue to work with ESTEC, BIRA, and QINETIQ to further implement the method and perform benchmark tests

•Develop characteristic radiation degradation curves for current state-of-the-art solar cell technologies

•Develop capabilities for other devices and irradiation particles

Future Work


Dr. Scott R. Messenger SFA, Inc. ([email protected])

Documents

Transcript of Dr. Scott R. Messenger SFA, Inc. ([email protected])