Overview on Spacecraft Charging Study in Japan

Mengu ChoMengu ChoLaboratory of Spacecraft Environment Interaction Engineering

Kyushu Institute of Technology

Koga Kiyokazu Koga, Hideki Koshiishi and Kumi NittaJapan Aerospace Exploration Agency

Acknowledgement: Colleagues in Japan

September 20, 2010

1

p ,11th Spacecraft Charging Technology Conference, Albuquerque, NM, USA

Contents• Simulation study• Electrostatic discharge research in laboratoryElectrostatic discharge research in laboratory• Characterization of charging properties

P i f fli h i d• Preparation for flight experiment and demonstration

• In-orbit space environment measurement• Guideline

2

MUSCAT Improvement

• Fast & Stabilized ComputationInternal Charging Sim lation• Internal Charging Simulation

• Plasma Environment DataA l El t E• Auroral Electron Energy Distribution Li St d Al• Linux Stand Alone

• Simulation of Charging Mitigation by NeutralizerMitigation by Neutralizer

• & etc.

Charging Analysis of a Solar SailFor the Next-generation, Interplanetary-Flight Spacecraft

@1.0AU

IKAROS ©JAXA

Membrane: Al-coated PolyimideArea: 14x14(m2), Thickness: ~10-6(m)( ), ( )

S/C Charging & Charged Particle Profiles:For S/C & Payload Design

4Paper on Wednesday

Charging Analysis of a Solar SailSolar Flux & Plasma flow: left to right, dx=0.5m, Plasma environment@1.0AU

ambient electron ambient ion

photoelectron electric potentialp otoe ect o p

5Paper on Wednesday

PIC Simulations of a Double-Probe Electric Field Sensor onboard Scientific Spacecraft Using the EMSES Codep g

Miyake, Y. (Kyoto Univ.), H. Usui (Kobe Univ.), and H. Kojima (Kyoto Univ.)

Application of space plasma PIC simulation to the analysis of time-

EMSES Code (Electro-Magnetic Spacecraft Environment Simulator)

dependent electromagnetic environment of scientific spacecraft

[Miyake and Usui, Phys. of Plasmas, 16, 062904, 2009]• Full PIC electromagnetic code• Modeling of spacecraft immersed in space plasmag p p p• Time-dependent spacecraft-plasma interactions including EM-field evolution

- Spacecraft charging, Plasma and EM-field environment around S/CEMSES simulation Linear theory

• Rectangular, uniform grid system • High performance computing by parallelization with domain decomposition

EMSES simulation Linear theoryre

quen

cy

parallelization with domain decomposition using MPI

Dispersion relation of EM sheath wave propagating along S/C surface

Fr

Wave number

Bias current circuitBepiColombo/MMO to Mercury

Application of EMSES to simulations of a double-probe electric field sensor

~ 4 V100 101 V

ee e

Sensing element(nearly at a space potential)Spacecraft

Boom

e: photoelectron

4 V100 ~ 101 V

Guard electrode(negatively charged by reference to s/c)

StubMEFISTO: Electric field sensor

Structure of MEFISTODensity plot of photoelectrons

emitted by the s/c bodySunlight

•PIC simulations with EMSES

D i f h d l d

•PIC simulations with EMSES

D i f h d l d

s/c

Guard (-25V)

ProbeSunlight - Demonstration of the guard electrode

to repel PEs coming from the s/c body.

- PE behavior around the sensor

- Demonstration of the guard electrode to repel PEs coming from the s/c body.

- PE behavior around the sensor

Photoelectrons emitted by s/c body areeffectively repelled by the guard operation

- Study on the conditions for the guard electrode operation to repel the PEs effectively

- Study on the conditions for the guard electrode operation to repel the PEs effectivelyyy

Application to scientific payload design and data calibration

Electrostatic discharge research in laboratory

8

ESD test on solar array

http://www.spacechina.com/cpyjs wxyhtq Detai

• ESD tests on solar array continues at KIT based on ISO-11221 9

p p pyj _ y q_ls.shtml?recno=48130

Flashover propagation experiment2 solar array panels with 2m x 1.2m

6

v=5.3t-0.5

gap: 6cm

Discharge point Poten

Propagate to 3m

ntial, kVV

Flashover jumped the gap

Joint experiment by KIT and JAXA

Solar array ESD researches at KIT• Effect of temperature on arc rate• Effect of water molecule adsorption p

on arc rate• Aging effect• Arc initiation method• Secondary arc mitigation by current

Cracks observed in grouting after agingy g y

oscillation with capacitor and inductor

~100μ• Flashover simulator• Orbital demonstration of high

Needles

100μm

voltage solar array technology11

Solar cell

Primary arc triggerPapers in this conference

ESD from electrically floating electrodes due to internal charging

E=7keV

-4500

-4000

0.1 mm thick poly-imide substrates with floating electrodes

Electrode 2

Electrode 1

Electrode 3

Electrode 5

0.1mm 1mm

m

40mm

4000

-3500

-3000

ntia

l (V

)

Electrode 3Electrode 2

Electrode 2 Electrode 3

Electrode 4

100m

m90m

m

80mm

mm

40m

m

-2500

-2000

-1500uraf

ace

Pot

en

Electrode 4

100mm

40m

2mm -1000

-500

S

S f 00 50 100 150 200

Time (min)Electrodes#2, #3: electrically floating#1 #5: grounded through electrometer

Time dependences of surface potentials of fl ti l t d i di t d ith l t

Shape of sample

12

#1, #5: grounded through electrometer#4, backing: grounded

floating electrodes irradiated with electron energy of 7keV and beam current density of 0.1 nA/cm2

Characterization of charging propertiesCharacterization of charging properties

13

Internal charge measurement in bulks using Pulsed Electro-Acoustic(PEA) method at TCU

PEA t・The internal charge accumulation and distribution in dielectrics can be observed using PEA method. PEA systemfor radiation

PI filmElectrode Electrode Electrode ElectrodePI film・Observed

NegativePositive

charge accumulation in the bulks of PI films irradiated by the Electron

Protonbeams.

The internal charge accumulation and distribution in dielectrics can be observed using PEA method.

50

(z) [

C/m

3 ]

5

10

15E-beam Proton-beam

z) [C

/m3 ]

-50

0

arge

Den

sity

(

-10

-5

0

rge

Den

sity

(z

Electron beam irradiation(80keV) Proton beam irradiation(2MeV)

-50

0 125

Cha

-15

10

0 125Position z [m]Position z [m]

Cha

Paper on ThursdayNow ,Developing the new internal & surface charge measurement system using improved PEA method.

Electron beam induced charging of insulating materialsat Nara National College of Technology

1 E+19

125m silvered Teflon FEP

0

4000

0 5 10 15 20

Electron Energy (keV)

1.E+18

1.E+19

y (o

hm_m

)

-8000

-4000

0 5 10 15 20

ace

Pot

entia

l (V

)

E=2.7keV

1.E+17

1.E 18

lum

e R

esis

tivity

EII in SEE yield

-12000

8000

Sur

fa

Jb≒0.1nA/cm2

1.E+1616000 12000 8000 4000 0

Vo

3000-16000

-16000 -12000 -8000 -4000 0Surface Potential @60min (V)

3000

Electron energy dependence of surface potential in case of beam current density

Surface potential dependence of volume resistivity obtained from the charge decay

15

potential in case of beam current density Jb= 0.1 nA/cm2 for 60 minutes

resistivity obtained from the charge decay characteristics after electron irradiation.

Characterization of charging properties of degraded material at KIT

S d l– Secondary-electron– Photo-electron

Volume and surface conductivity by charge storage method

Papers in this conference

– Volume and surface conductivity by charge storage method

conductivityAO

AO facility

16SEE & PEEUV

Characterization campaign of charging properties of degraded material sponsored by

Material property The range of primary energy Place

Framework for the Measurements of Materials Properties ParameterJAXA

Secondary electron emission (SEE)

Accelerating voltage: 600V-5kV

The High Energy Accelerator Research Organization (KEK)

Accelerating voltage: 200V-1kV

JAXA &Tokyo City university

Photoelectron emission Wavelength 30 to 250 nm KEKPhotoelectron emission (PE)

Wavelength 30 to 250 nm KEK

Wavelength 110 to 400 nm Tokyo City universityBulk resistivity, ASTM D-257, JIS C2139 Saitama UniversitySurface resistivity

Bulk resistivity Charge storage method Saitama University

Di l t i C t t S it M t l T h l

17

Dielectric Constant Sumitomo Metal Technology Inc.

Charging/discharging properties at EOLCharging/discharging properties at EOLCharging/discharging properties at EOLCharging/discharging properties at EOL

NASA Photo

Charging/dischargingCharging/discharging propertiesproperties ofof manymany materialsmaterialswerewere studiedstudied throughthrough collaborationcollaboration ofof JAXAJAXA andandT08216AC

100T08216AC

100T08216AC

100T08216AC

100

werewere studiedstudied throughthrough collaborationcollaboration ofof JAXAJAXA andandKobeKobe UniversityUniversity.. WellWell--characterizedcharacterized 88 km/km/ss atomicatomicoxygenoxygen beambeam waswas usedused forfor simulatingsimulating LEOLEO spacespaceenvironmentenvironment atat KobeKobe UniversityUniversity..Charging/dischargingCharging/discharging propertiesproperties ofof thethe simulatedsimulatedEOLEOL samplessamples werewere analyzedanalyzed byby JAXAJAXA andand SaitamaSaitamaU i itU i it

T08216ACNote: longitude is not devided by flight time

Inte

nsity

(cou

nts)

20

40

60

80Note: longitude is not devided by flight time

Inte

nsity

(cou

nts)

20

40

60

80

Approx. 8 km/s

T08216ACNote: longitude is not devided by flight time

Inte

nsity

(cou

nts)

20

40

60

80Note: longitude is not devided by flight time

Inte

nsity

(cou

nts)

20

40

60

80

Approx. 8 km/s

UniversityUniversity..

TOF distribution of oxygen atomTOF distribution of oxygen atom

Flight time (s)

-200 0 200 400 600 800 1000 1200 14000

Flight time (s)

-200 0 200 400 600 800 1000 1200 14000

TOF distribution of oxygen atomTOF distribution of oxygen atom

Flight time (s)

-200 0 200 400 600 800 1000 1200 14000

Flight time (s)

-200 0 200 400 600 800 1000 1200 14000

t

Charge Storage Method for Volume Resistivity in Space Environment at TCU

• Vacuum and E-beam• Volume resistivity is calculated from the

d k d i k l

d

t

eVtV 0)(

dark current decay constant in week long surface potential history

Test parameters

Temperature charge residual at cryogenic temperature

Electron energy and flux range and dose effect (RIC)

Sample thickness E-field 1exp T

penhancement

19

*A.R. Frederickson and J.R. Dennison, IEEE Trans. on Nuc. Sci., Vol. 50, No. 6(2003)

Conductivity Measurement in Vacuum using Conventional Method at TCU ・The conductivity of dielectrics for spacecraft is observed using the conventional method

(ASTM D257,JIS K6911)

10-14

Kapton-V真空Kapton V

Kapton in air atmosphereKapton in vacuum

(ASTM D257,JIS K6911)

・We confirm that the PI’s conductivity decrease in vacuum condition.

M t t

10-16

10-15

電率

[S

/m]

真空Kapton-V

Ohmic low

Kapton in vacuum

uctiv

ity

[S/m

]

Child low

Measurement electrode system

Vacuum chamber

Measurement system

20 40 60 80 100 120 140 16010-17

10

電界 E [kV/mm]

導電

Applied Electric Filed E [kV/mm]

Con

du

Child low

10-15

10-14

/m]

Apical-NPI真空Apical-NPI

Apical in air atmosphereApical in vacuum

m] Ohmic low

電界 E [kV/mm]Applied Electric Filed E [kV/mm]

Current

HV

10-16

10

導電率

[S

/C

ondu

ctiv

ity

[S/m

Digital electro mater

20 40 60 80 100 120 140 16010-17

電界 E [kV/mm]Applied Electric Filed E [kV/mm]

C

High Voltage Power Supply

Lunar Dust Charging• Experiment on dust charging and subsequent levitation

21Poster in this conference

Joint work of KIT and USC

Preparation for flight experiment and demonstration

22

Development of surface charging sensor• Application of COTS potential monitor to

satellite surface potential monitor

Trek 820 potential meter Environment test modelTrek 820 potential meter Environment test model•Conversion of ultra-high impedance contact-type•Sensor head as small as 1mm or less

23

•Mulitple-sensor head to measure deep dielectric charging

Poster in this conference

Spacecraft Charging Mitigation

• Electron-emitting Film for Spacecraft Charging Mitigation (Elf’s CHARM)g ( )– To be launched in as early as Nov. 2011

• Semi-conductive transparent coatingSemi-conductive transparent coating Space plasma (potential reference)

Energetic ee e

gelectrons

++

+

++

++

++++++Field emitted electrons

Cupper

Spacecraft chassis ( )Conductive

+++++Polyimide

ELF/GEO ELF/PEO

Space potential

(metal)Conductive adhesivePolyimide/Copper Fluorine Polymer/Copper

Paper in this conference

Electrodynamic bare tether• Preparation for orbital demonstration on a small

satellite– Field Emission Cathodes using Carbon Nanotube

(Paper on Thursday)( p y)– Arc suppression (poster in this conference)

25Bare tether sampleEDT Discharge positions

PASCAL (Primary Arcing effects on Solar Cells at LEO)

• To be launched to ISS in February 2011– Characterize solar cell degradation due to arcing– Active experiment with COTS-based electronics for biasing

cells and collecting data

http://iss.jaxa.jp/iss/ulf3/mission/overview/eva/eva3/

PASCAL electronics box

26

In-orbit space environment measurement

27

Instruments onboard (LEO) GOSAT

S di ti i tISSSpace environment data acquisition

instruments (SEDA-AP)

Space radiation environment detectors (TEDA/ LPT)

ISS

JASON-2

Space radiation en ironment

ALOS

28

Space radiation environment detectors (TEDA/ SDOM)

Space radiation environment detectors (TEDA/ LPT)

Instruments onboard (GEO)

DRTSETS8

Space environment monitors (TEDA/MAM,POM)

Space radiation environment detectors (TEDA/ SDOM)

( )

QZS-1

29Space environmental monitors (TEDA/LPT, MAM, POM)

Spacecraft charging design guideline• JERG-2-211 “Satellite Design Guideline for Charging

and Discharge”– Published in 2009– Characterization Campaign

• Material data for charging simulation• Solar array secondary arcy y

30