Solar Cell Radiation Environment Analysis Models (SCREAM)

Similar documents
Space Solar Cell Radiation Damage Modelling

Displacement Damage Characterization of Electron Radiation in. Triple-Junction GaAs Solar Cells

Radiation Analysis of InGaP/GaAs/Ge and GaAs/Ge Solar Cell: A comparative Study

S5p INTENTIONALLY BLANK

AE9/AP9 Proton Displacement Damage Kernels (version 2)

The AE9/AP9 Radiation and Plasma Environment Models

HIGH ENERGY IRRADIATION PROPERTIES OF CdTe/CdS SOLAR CELLS

SREM: 8 years experience of radiation monitoring with a standard instrument

AE9/AP9-IRENE space radiation climatology model

Radiation Transport Tools for Space Applications: A Review

Introduction. Neutron Effects NSEU. Neutron Testing Basics User Requirements Conclusions

Nonionizing Energy Loss (NIEL) for Protons

Shielding Considerations

DIN EN : (E)

Radiation Environments, Effects and Needs for ESA Missions

Air Force Research Laboratory

Space Environment Impacts on Space Solar Power system

TACSAT-4 SOLAR CELL EXPERIMENT: TWO YEARS IN ORBIT

AE9/AP9 Electron Displacement Damage Kernels

Estec final presentation days 2018

Predicting On-Orbit SEU Rates

Solar particle events contribution in the space radiation exposure on electronic equipment

Radiation Effects in MMIC Devices

Lunar Reconnaissance Orbiter Project. Radiation Environment Specification. August 25, 2005

Evaluation of the New Trapped Proton Model (AP9) at ISS Attitudes. Francis F. Badavi. (NASA Langley Radiation Team)

PROBLEM SET #3 TO: FROM: SUBJECT: DATE: MOTIVATION PROBLEM STATEMENT

Modeling of charge collection efficiency degradation in semiconductor devices induced by MeV ion beam irradiation

Shields-1, A SmallSat Radiation Shielding Technology Demonstration

The AE9/AP9 Radiation Specification Development

Study the Effect of Proton Irradiation for Photovoltaic Cells Characteristics in LEO Orbit

SOUTH ATLANTIC ANOMALY AND CUBESAT DESIGN CONSIDERATIONS

Introduction to Radiation Testing Radiation Environments

Comparison of JGO and JEO

REPORT DOCUMENTATION PAGE

NOAA Space Weather Prediction Center Data and Services. Terry Onsager and Howard Singer NOAA Space Weather Prediction Center

A New JPL Interplanetary Solar HighEnergy Particle Environment Model

Internal Charging Hazards in Near-Earth Space during Solar Cycle 24 Maximum: Van Allen Probes Measurements

Data and Models for Internal Charging Analysis

SPENVIS Tutorial: Radiation models in SPENVIS and their accuracy

Study of the radiation fields in LEO with the Timepix detector

Developing AE9/AP9 Kernels from Third-Party Effects Codes

CRaTER Science Requirements

The Los Alamos Laboratory: Space Weather Research and Data

Internal charging simulation at a Galileo like orbit Effect of the anisotropic shielding and of the environment definition

NASA Use and Needs for Radiation and Spacecraft Charging Models

H. Koshiishi, H. Matsumoto, A. Chishiki, T. Goka, and T. Omodaka. Japan Aerospace Exploration Agency

Radiation Environment and Radiation Dosimetry in the Upper Atmosphere

APPLICATION OF POLYMERIC NANO COMPOSITES AT LOW EARTH ORBIT AND GEOSYNCHRONOUS EARTH ORBIT

JUICE/Laplace Mission Summary & Status

Radiation: Lessons Learned

Space Station Ionizing Radiation Design Environment

IAC-08-A MONTE CARLO SIMULATIONS OF ENERGY LOSSES BY SPACE PROTONS IN THE CRATER DETECTOR

Radiation Environment. Efforts at JPL. Dr. Henry Garrett. Jet Propulsion Laboratory 4800 Oak Grove Dr. Pasadena, CA 91109

Monitoring solar energetic particles with ESA SREM units

RADIATION OPTIMUM SOLAR-ELECTRIC-PROPULSION TRANSFER FROM GTO TO GEO

The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) Investigation for the Lunar Reconnaissance Orbiter

Jovian radiation models for JUICE mission

RAD Hard Selection Process for RHA Devices as an Element of Design

L2 Natural Environment Summary

w w w. o n e r a. f r

Cosmic Ray Effects on Micro- Electronics (CRÈME) Tools Brian Sierawski 2017 SEESAW

Simulation of Radiation Effects on NGST. Bryan Fodness, Thomas Jordan, Jim Pickel, Robert Reed, Paul Marshall, Ray Ladbury

MATERIALS FOR LIGHTWEIGHT RADIATION SHIELD FOR CANADIAN POLAR COMMUNICATIONS AND WEATHER (PCW) SATELLITE MISSION

SIMULATION OF SPACE RADIATION FOR NANOSATELLITES IN EARTH ORBIT *

RADIATION DAMAGE IN HST DETECTORS

Estimating Space Environment Effects during All-Electric Telecom Satellite Missions

Model and Data Deficiencies

Van Allen Probes Mission and Applications

BravoSat: Optimizing the Delta-V Capability of a CubeSat Mission. with Novel Plasma Propulsion Technology ISSC 2013

Evaluation of Various Material Properties to Shield from Cosmic Radiation Using FLUKA Transport Code

AE9/AP9/SPM: NEW MODELS FOR RADIATION BELT AND SPACE PLASMA SPECIFICATION

The Radiation Environment for the Next Generation Space Telescope

November 2013 analysis of high energy electrons on the Japan Experimental Module (JEM: Kibo)

Hans-Herbert Fischer and Klaus Thiel

Radiation Shielding Considerations for the Solar-B EIS CCDs - initial discussion EUV Imaging Spectrometer

Geant4 simulation for LHC radiation monitoring

Neutron Induced Nuclear Counter Effect in Hamamatsu Silicon APDs and PIN Diodes

Overview of current and future SPENVIS and Organisation of the tutorials. M. Kruglanski (BIRA-IASB)

Launched April 01, reached Mars Oct. 01. Two-hour circular, polar mapping orbit established by Feb p.m. day/5 a.m. night

U.S. Radiation Dose Limits for Astronauts

physics/ Sep 1997

D E S I R E Dose Estimation by Simulation of the ISS Radiation Environment

Chapter V: Cavity theories

Space Radiation Mitigation for Fox-1

Jovian Radiation Environment Models at JPL

Radiation Belt Analyses: needs, data and analysis

Radiation and Activation with SoLID. Outline

AE9/AP9 Internal Charging Kernel Utility Beam-Slab Geometry Adapted to Hemispherical Shell for Aluminum Shields

Slot Region Radiation Environment Models

Radiation Effects on Electronics. Dr. Brock J. LaMeres Associate Professor Electrical & Computer Engineering Montana State University

DESIGN STANDARD SPACE ENVIRONMENT EFFECTS MITIGATION

Line-Focus and Point-Focus Space Photovoltaic Concentrators Using Robust Fresnel Lenses, 4-Junction Cells, & Graphene Radiators

USING SPACE WEATHER VARIABILITY IN EVALUATING THE RADIATION ENVIRONMENT DESIGN SPECIFICATIONS FOR NASA'S CONSTELLATION PROGRAM

Space Radiation Dosimetry - Recent Measurements and Future Tasks

Low energy electrons in the inner Earth s magnetosphere

A survey of Radiation Hazards & Shields for Space Craft & Habitats

Theory and Modeling (High Performance Simulation)

Those Upsetting Ions-The Effects of Radiation on Electronics

Solar Orbiter Environmental Specification

ICALEPCS Oct. 6-11, 2013

Transcription:

Solar Cell Radiation Environment Analysis Models (SCREAM) 2017 Space Environment Engineering & Science Applications Workshop (SEESAW) Scott R. Messenger, Ph.D. Principal Space Survivability Physicist Scott.messenger@ngc.com 410-993-3976

Space Radiation Environment for Solar Arrays Ionizing and nonionizing radiation electrons protons solar UV p + p + e - p + e- e - COVERGLASS ACTIVE CELL e - SUBSTRATE Omnidirectional (directional?) Energy Spectra (electrons & protons & plasmas) Nuclear activation (secondary production) Prompt effects (EMP, gammas, neutrons) p + p + PANEL p + e - p +

Outline Space Solar Cell Modelling Displacement Damage Dose (DDD) Model SCREAM SCREAM Success Stories TacSat4 GPS-IIR SV41 Low Thrust Trajectories (DDD accumulation) Summary 3

Integral Fluence(cm -2 ) Normalized Maximum Power Normalized Maximum Power Space Solar Cell Degradation Prediction: The Problem To generate ground irradiation data necessary to predict the effect of a space particle energy spectrum on a solar cell This is accomplished by reducing the ground data to a characteristic dataset 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 1.E+09 1.E+08 1.E+07 1.E+06 Electron & Proton Spectra for TacSat4 TACSAT4 Orbit (700 x 12050 km, 63.4 o, 1 year) THIS FIGURE IS FOUO 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 Particle Energy (MeV) Trappped Protons Solar Event Protons Trapped Electrons 1.0 0.9 0.8 0.7 0.6 Electron & Proton Ground Irradiation Data (Single Junction GaAs/Ge, 1991) 0.5 0.6 0.4 Protons 50 kev 0.5 100 kev 0.4 0.3 200 kev Electrons 300 kev 0.3 0.2 500 kev 0.6 MeV 1 MeV 1 MeV 0.1 3 MeV THIS FIGURE IS FOUO 0.2 2.4 MeV 9.5 MeV 12 MeV 0.1 0.0 1.0E+09 1.0E+10 1.0E+11 1.0E+12 1.0E+130.0 1.0E+14 1.0E+15 1.0E+16 1.0E+17 Particle Fluence 1.0E+09 (#/cm 2 1.0E+10 ) 1.0E+11 1.0E+12 1.0 0.9 0.8 0.7 GaAs/Ge 1 Sun, AM0 25 o C

mining Maximum Power Remaining Maximum Power Reamining Maximum Power Space Solar Cell Degradation Prediction: The Solution(s) 1. JPL method RDCs equivalent 1 MeV electron fluence & C pe JPL Model Data Collapse 1.0 0.9 0.9 GaAs/Ge 0.8 200 kev (1 sun, AM0 0.8 300 kev 0.7 500 kev 0.7 1.0 0.6 1 MeV 0.6 3 MeV 0.9 0.5 0.5 Protons Electrons 9.5 MeV 0.8 0.4 200 kev 12 MeV 0.4 300 kev 2.4 MeV 0.7 0.3 0.3 500 kev 1 MeV 0.6 0.2 1 MeV 0.6 MeV 0.2 0.1 3 MeV 1 MeV Equiv. U235 neutrons 0.5 0.1 9.5 MeV DDD Fit 0.0 THIS FIGURE IS FOUO 0.4 0.0 12 MeV 1.E+07 1.E+08 1.E+09 1.E+10 1.E+12 2.4 1.E+13 MeV 1.E+14 1.E+15 1.E+16 1.E+17 0.3 Equivalent 1 MeV 1 MeV Electron Fluence (cm -2 ) 0.2 GaAs (1 sun, AM Displacement Damage Dos *The heritage JPL model is well documented (1970-2000): H.Y.Tada and J.R.Carter, Solar Cell Radiation Handbook, JPL Pub. 77-56 (1977) Green Book (Si) B.Anspaugh, GaAs Solar Cell Radiation Handbook, JPL Pub. 96-9 (1996) Blue Book (GaAs) D.C. Marvin, Assessment of Multijunction Solar Cell Performance in Radiation Environments, TOR-00(1210)-1

mining Maximum Power Remaining Maximum Power Reamining Maximum Power Reamining Maximum Power Remaining Maximum Power Reamining Maximum Power Space Solar Cell Degradation Prediction: The Solution(s) 1. JPL method RDCs equivalent 1 MeV electron fluence & C pe 2. NRL method NIEL displacement damage dose (DDD) JPL Model Data Collapse 1.0 0.9 0.9 GaAs/Ge 0.8 200 kev (1 sun, AM0 0.8 300 kev 0.7 500 kev 0.7 1.0 0.6 1 MeV 0.6 3 MeV 0.9 0.5 0.5 Protons Electrons 9.5 MeV 0.8 0.4 200 kev 12 MeV 0.4 300 kev 2.4 MeV 0.7 0.3 0.3 500 kev 1 MeV 0.6 0.2 1 MeV 0.6 MeV 0.2 0.1 3 MeV 1 MeV Equiv. U235 neutrons 0.5 0.1 9.5 MeV DDD Fit 0.0 THIS FIGURE IS FOUO 0.4 0.0 12 MeV 1.E+07 1.E+08 1.E+09 1.E+10 1.E+12 2.4 1.E+13 MeV 1.E+14 1.E+15 1.E+16 1.E+17 0.3 Equivalent 1 MeV 1 MeV Electron Fluence (cm -2 ) 0.2 GaAs (1 sun, AM Displacement Damage Dos NRL/DDD Model Data Collapse 1.0 0.9 0.8 0.7 1.0 0.6 0.9 0.5 1.0 0.9 0.8 0.7 0.6 0.5 Protons 200 kev 300 kev 500 kev 1 MeV 3 MeV Electrons 9.5 MeV GaAs/Ge (1 sun, AM0 0.8 200 0.4keV 12 MeV 0.4 300 kev 2.4 MeV 0.7 0.3 0.3 500 kev 1 MeV 0.6 10.2 MeV 0.6 MeV 1 MeV Eq. 235 U 0.2 30.1 MeV 1 MeV Equiv. U235 Neutrons neutrons 0.5 9.5 MeV DDD Fit 0.4 0.1 0.0 12 MeV 1.E+07 1.E+08 THIS 1.E+09 FIGURE 1.E+10 IS FOUO 1.E+1 2.4 MeV 0.3 0.0 Displacement Damage Dose (MeV/g) 1 MeV 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 0.2 0.6 MeV 0.1 Displacement Damage Dose (MeV/g) 1 MeV Equiv. U235 neutrons GaAs/ (1 sun, AM0 GaAs/Ge (1 sun, AM0 25 o C) *The advanced NRL/DDD model is well documented (1994-2012): S.R. Messenger, et al., "Modeling solar cell degradation in space: A comparison of the NRL displacement damage dose and JPL equivalent fluence approaches", Prog. Photovolt.: Res. Appl. vol. 9, pp. 103-121, 2001. S.R. Messenger, et al., "SCREAM: A new code for solar cell degradation prediction using the displacement damage dose approach," 35th IEEE PVSC, 2010, p. 1106.

Normalized Maximum Power Normalized Maximum Power NRL DDD Method Data needed (*AIAA S-111) Protons E > 1-4 MeV (need uniform DD) (f = 10 10 to 10 13 p + /cm 2 ) Electrons E = 1 & >2 MeV (f = 10 13 to 10 16 e - /cm 2 ) Advantages ~3-4X cost reduction in qualification Convenient for new tech quals, design tweaks, requals Disadvantages Heritage Heritage Heritage Not applicable to protons on thick silicon Electron and Proton Ground Data 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 Protons 3 MeV THIS FIGURE IS FOUO 0.0 0.0 1.0E+09 1.0E+10 1.0E+11 1.0E+12 1.0E+13 1.0E+14 1.0E+091.0E+15 1.0E+101.0E+16 1.0E+111.0E+17 1.0E+12 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 Particle Fluence (#/cm 2 ) GaAs/Ge 1 Sun, AM0 25 o C Electrons 0.6 MeV 1 MeV 2.4 MeV 12 MeV Particle F Qualification and Quality Requirements for Space Solar Cells (AIAA S-111A-2014) JPL and/or DDD models acceptable

Space Solar Cell Modeling: NRL Displacement Damage Dose (DDD)

NRL Displacement Damage Dose Model for Solar Cell EOL Calculations Determine Incident Particle Spectrum (e.g. AP8, AE8) Input Nonionizing Energy Loss (NIEL) Data (Energy Dependence of Damage Coefficients) Calculate Slowed-Down Spectrum (SDS) (Shielding) Determine Characteristic Degradation Curve vs. DDD (NIEL x Fluence) (2 e - and 1 p + energy) Calculate DDD for Mission (Integrate SDS with NIEL) Read Off EOL Value *RED Measurements *Blue Calculation *Green Data input

Differential Fluence (p + /cm 2 /MeV) DDD EOL Prediction Method 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 Omnidirectional Spectra TrP/2 1 mil 3 mils 6 mils 12 mils 20 mils 30 mils 60 mils 1.E+09 1.E+08 1.E+07 1.E+06 1.E+05 THIS FIGURE IS UNCLASSIFIED 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)

Differential Fluence (p + /cm 2 /MeV) Nonionizing Energy Loss (MeVcm 2 /g) DDD EOL Prediction Method 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 1.E+09 Omnidirectional Spectra TrP/2 1 mil 3 mils 6 mils 12 mils 20 mils 30 mils 60 mils Nonionizing Energy Loss (2006) 1.E+01 1.E+00 1.E-01 GaAs 1.E+08 1.E+07 1.E+06 1.E+05 THIS FIGURE IS UNCLASSIFIED 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) 1.E-02 1.E-03 THIS FIGURE IS UNCLASSIFIED 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)

Displacement Damage Dose (MeV/g) Differential Fluence (p + /cm 2 /MeV) Nonionizing Energy Loss (MeVcm 2 /g) DDD EOL Prediction Method 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 1.E+09 Omnidirectional Spectra TrP/2 1 mil 3 mils 6 mils 12 mils 20 mils 30 mils 60 mils Nonionizing Energy Loss (2006) 1.E+01 1.E+00 1.E-01 GaAs 1.E+08 1.E+07 1.E+06 1.E+05 1.E+13 1.E+12 THIS FIGURE IS UNCLASSIFIED 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) Total Mission DDD THIS FIGURE IS UNCLASSIFIED 1.E-02 1.E-03 THIS FIGURE IS UNCLASSIFIED 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) 1.E+11 1.E+10 1.E+09 1.E+08 1.E+07 0 10 20 30 40 50 60 70 SiO2 Coverglass Thickness (mils)

Displacement Damage Dose (MeV/g) Remaining Maximum Power Differential Fluence (p + /cm 2 /MeV) Nonionizing Energy Loss (MeVcm 2 /g) DDD EOL Prediction Method 1.E+16 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 1.E+09 Omnidirectional Spectra TrP/2 1 mil 3 mils 6 mils 12 mils 20 mils 30 mils 60 mils Nonionizing Energy Loss (2006) 1.E+01 1.E+00 1.E-01 GaAs 1.E+08 1.E+07 1.E+06 1.E+05 1.E+13 1.E+12 THIS FIGURE IS UNCLASSIFIED 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) Total Mission DDD THIS FIGURE IS UNCLASSIFIED 1.E-02 1.E-03 1.0 0.9 THIS FIGURE IS UNCLASSIFIED 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) P max Degradation GaAs/Ge (AM0, 1 sun, 25 o C) 1.E+11 1.E+10 1.E+09 1.E+08 0.8 0.7 0.6 0.5 0.4 Data Fit (a, C, D x ) P ( D d ) D d A C log 1 P 0 Dx THIS FIGURE IS UNCLASSIFIED protons electrons neutrons 1.E+07 0 10 20 30 40 50 60 70 SiO2 Coverglass Thickness (mils) 0.3 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 DDD(protron) and DDD(1 MeV electron) (MeV/g)

SCREAM (Solar Cell Radiation Environment Analysis Models) Excel file driven menus as inputs Input integral radiation spectra Single & multi-spectra, electron and proton Shielding material Nonionizing energy loss (NIEL) Multilayer shielding Parametric degradation coefficients (GaAs, ITJ, UTJ, ATJ, Si-electrons, user) Output Slowed-down radiation spectra End-of-life (EOL) predictions DDD only options ( ShielDDDose ) Trajectory capability through Time Series Spectra input option SCREAM is available by request in CD format *Contact: Dr. Scott R. Messenger (NGC)

SCREAM Success Stories TacSat4 (HEO: 700 km x 12,050 km, 63.4 o ) Used onboard dosimetry (CEASE-II) and solar cell experiment to explain anomalously large solar array degradation rates SCREAM used CEASE-II data to corroborate solar cell experiment (full IV) data and re-project mission lifetime GPS-IIR SV41 (MEO: 20,200 km, 55 o ) GPS has been plagued with anomalous solar array degradation since onset (many mitigation paths successful, but anomaly continues) SCREAM used LANL BDD Detector data to help understand damage mechanisms and eliminate displacement damage as the anomaly Low-Thrust Trajectory Orbit to GEO (LT2GEO) Low-thrust trajectories are extreme mass & cost cutting measures Spacecraft subjected to extreme proton belts SCREAM can simply analyze accumulated DDD to optimize LT trajectory

TacSat4 (HEO: 700 km x 12,050 km, 63.4 o ) NRL satellite launched 27 Sept. 2011 (Kodiak, AK) >1 MeV electrons >10 MeV protons * Graphic created using AFGEOSPACE (V2.5)

Remaining Maximum Power TacSat4 (HEO: 700 km x 12,050 km, 63.4 o ) Trapped Protons Dominant Maximum Power Degradation on Emcore ATJ Solar Cell 1.00 0.95 AP9Mean Shielding 6 mils CMG 2 mils DC 93-500 Emcore BTJM 3J 0.90 0.85 0.80 0.75 AP8MIN AP9-MC-95 th 1 year spec 0.70 Measured power exceeds predictions using AP9 95 th worst case environment! 0.65 9/27/2011 10/27/2011 11/26/2011 12/26/2011 1/25/2012 2/24/2012 3/25/2012 Date of Mission

TacSat4 (HEO: 700 km x 12,050 km, 63.4 o ) Trapped Protons Dominant Two additional payloads on-board AFRL: CEASE-II dosimeter package Several dosimeters (particle fluence, TID, SEE, SC) 0.7-80 MeV protons & 0.05-3 MeV electrons NRL: Two solar cell experiments yielding full IV curves SCE#1: SolAero BTJM (3J w/ 6 mil CMG coverglass) CEASE-II SCE #1

CEASE Proton Energy Comparisons

CEASE Proton Energy Comparisons

CEASE Proton Energy Comparisons *For 6 mil coverglass, omnidirectionally incident protons having energy from 1-10 MeV are the most important in causing damage to the underlying cell. For 12-20 mil covers -- NO ANOMALY --- but definitely NO FUN.

Displacement Damage Dose (MeV/g) TacSat4 (HEO: 700 km x 12,050 km, 63.4 o ) Trapped Protons Dominant SCREAM: Environment data through 6 mil CMG & 2 mil adhesive 9.0E+07 8.0E+07 7.0E+07 CEASE SCREAM CEASE Shielding 6 mils AP8MIN CMG 2 mils DC AP9Mean 93-500 Emcore AP9-MC-95th BTJM 3J 6.0E+07 5.0E+07 4.0E+07 AP9-95 th 3.0E+07 2.0E+07 AP8MIN 1.0E+07 AP9Mean 0.0E+00 9/14/2011 12/23/2011 4/1/2012 7/10/2012 10/18/2012 1/26/2013 5/6/2013 Date of Mission

Remaining Parameter TacSat4 (HEO: 700 km x 12,050 km, 63.4 o ) Trapped Protons Dominant SCREAM: DDD results applied to SolAero ATJ solar cell technology 1.00 0.95 Isc 10 16 (Equiv. 1 MeV electron fluence) 2x10 16 0.90 0.85 0.80 Voc 0.75 0.70 0.65 Pmax Shielding 6 mils CMG 2 mils DC 93-500 Emcore ATJ 0.60 SOLID: SCREAM calculations using CEASE environment data DOTTED: Onboard data collected from solar cell experiment 0.55 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Jan-13 Mar-13 Date of Mission

GPS-IIR (MEO: 20,200 km, 55 o ) SVN41 Launched 10 Nov 2000 *NIM A 482, 653 (2002)

12/10/00 12/10/01 12/10/02 12/10/03 12/10/04 12/10/05 12/10/06 12/10/07 12/10/08 12/10/09 Remaining Current at 28.28V GPS-IIR (MEO: 20,200 km, 55 o ) Trapped Electrons Dominant GPS spacecraft have shown anomalous silicon solar array degradation throughout [>30] year existence (Marvin, 1988) 1.00 0.98 0.96 0.94 0.92 0.90 0.88 0.86 0.84 0.82 0.80 0.78 0.76 0.74 0.72 0.70 0.68 Solar array telemetry data AE8MAX GPS SVN 41 (Block IIR-6) AE8MAX+ESP(50%) ~25% deviation after 9 yrs! Many possibilities posed (coatings, coverglass, contamination, ESD, radiation environment related) but none confirmed GPS III plans on using oversized arrays to maintain necessary EOL levels

GPS-IIR (MEO: 20,200 km, 55 o ) Trapped Electrons Dominant LANL Burst Dosimeter Detector (BDD) onboard SVN41 Ion-implanted Si detectors behind varying shielding levels Gives electron fluences for E>0.04 to >10 MeV Gives proton fluences for E>0.05 to >6 MeV Daily fluence and energy spectra supplied by LANL *LA-UR-10-04234, LA-UR-08-2816

GPS-IIR (MEO: 20,200 km, 55 o ) Trapped Electrons Dominant SCREAM used BDD data to determine expected Si solar cell degradation behind 12 mil CMX coverglass Remaining Current @ 28.28 V 1.00 0.98 0.96 0.94 0.92 0.90 0.88 0.86 0.84 0.82 0.80 0.78 0.76 0.74 0.72 0.70 0.68 12/10/2000 12/10/2001 12/10/2002 12/10/2003 On-orbit correction 12/10/2004 Other damage mechanisms Displacement damage eliminated from secondary damage mechanism Other damage mechanism causing anomaly 12/10/2005 12/10/2006 AE8MAX AE8MAX + ESP Total (50%) LANL Electrons (JPL Model) LANL Electrons (NRL Model) Solar Array Current @ 28.28 V AE8 not so bad! 12/10/2007 12/10/2008 12/10/2009

12/10/2000 12/10/2001 12/10/2002 12/10/2003 12/10/2004 12/10/2005 12/10/2006 12/10/2007 12/10/2008 12/10/2009 Difference Between Model and Data GPS-IIR (MEO: 20,200km, 55 o ) Trapped Electrons Dominant Analytical determination between expected (SCREAM) and measured showed interesting trends (IEEE Trans. Nucl. Sci. 58, p.3188 (2011)) Fast rate (4%/yr): contamination, UV, photo-fixing --- AR coating/conductive oxide? Slow rate (1.5%/yr): trapped electrons --- coverglass damage, ESD (Ferguson et al. 2015)? 0.20 0.18 0.16 0.14 0.12 0.10 ~1.5%/year 0.08 0.06 0.04 0.02 ~4%/year *Two accumulative mechanisms for anomalous degradation suggested! 0.00

Low-Thrust Trajectory to GEO (LT2GEO) >1 MeV electrons >10 MeV protons Graphic created using AFGEOSPACE (V2.5) Reduced Launch Costs Increased Payload Trade Off Delayed GEO operations More Radiation Exposure

Altitude (km) Low-Thrust Trajectory to GEO (LT2GEO) 60000 50000 Minimum-Time Low-Thrust Trajectory *Initial Orbit - GTO 40000 30000 20000 10000 131 days to GEO 0 12/1/2017 12/31/2017 1/31/2018 3/2/2018 4/2/2018 5/2/2018 Date Along Trajectory

Particle Flux (#/cm 2 /s) Low-Thrust Trajectory to GEO (LT2GEO) Electron & Proton Fluxes Along Trajectory (AE8MAX/AP8MAX) 1.0E+07 1.0E+06 1.0E+05 1.0E+04 1.0E+03 1.0E+02 1.0E+01 AE8MAX (>1 MeV electrons) AP8MAX (>10 MeV protons) 1.0E+00 0 20 40 60 80 100 120 140 Days in Mission

DDD (MeV/g) Low-Thrust Trajectory to GEO (LT2GEO) Trapped Protons Dominant 1.0E+05 1.0E+04 DDD Along Trajectory (AE8MAX/AP8MAX) 4.83 mils CMG (4 mils CMG & 1 mils adhesive) AP8MAX AE8MAX 1.0E+03 1.0E+02 1.0E+01 1.0E+00 1.0E-01 1.0E-02 0 20 40 60 80 100 120 140 Days in Mission * Trapped protons dominate the DDD for the LT2GEO transfer

Remaining Pmax Low-Thrust Trajectory to GEO (LT2GEO) Trapped Protons Dominant 1.00 0.98 0.96 0.94 0.92 0.90 0.88 0.86 0.84 0.82 0.80 0.78 0.76 0.74 0.72 0.70 Solar Cell Degradation (AP8MAX/AE8MAX) Triple Junction Single Junction 4.83 mils CMG (4 mils CMG & 1 mil adhesive, infinite back) 0 20 40 60 80 100 120 140 Days in Mission After further 15 year GEO parked environment *The LT2GEO transfer significantly degrades both 1J and 3J solar cells

Summary SCREAM employs the DDD model for solar cell degradation Slab geometry (2p) Bonus Capabilities Multi-layered shielding Time series spectra (on-orbit data, trade studies) ShielDDDose (Depth-DDD curves) Applications Easy interpretation of dosimeter data onboard spacecraft for ORS TacSat4 helped understand extra radiation to project mission lifetime GPS eliminated DDD effects in solar cell to push efforts elsewhere LT2GEO aids in better solar array designs in present low-cost needs Not only for solar cells (LEDs, laser diodes, CCDs, etc.) Any ground data for which a parametric vs. DDD curve can be created

2024 © sciencedocbox.com Privacy Policy | Terms of Service | Feedback