Space Radiation Effects Tutorial E De Donder BIRA
Space Radiation Effects Tutorial E. De Donder (BIRA) 23/03/2012 at ROB www. spenvis. oma. be 1
Outline 1. 2. General overview picture Radiation environment § § 3. Radiation effects § § 4. GCR particles Solar particles Trapped particles Secondary particles Total Ionizing Dose (TID) Displacement Damage (DDD) Single Event Effects (SEE) S/c charging Solar storm threat-matrix 2
Radiation environment Plasma environment Neutral environment + drag Microparticle environment 3
Radiation environment (1/4): GCR particles § § protons and heavy ions (Z>1, mostly fully ionized) E ~ 0. 01 – 103 Ge. V/n modulated by solar cycle, Forbush decrease due to CME anomalous component : 1 x ionised He, N, O, Ne, Ar with 10 < E < 100 Me. V/n → only during sol. min. Magnetic rigidity = momentum per charge Energy required to penetrate Earth’s magnetic field (Stassinopoulos et al. , 2003) SPENVIS-4. 5 4
Radiation environment (2/4): Solar particles Solar wind: electrons, protons, heavy ions (single ionised) ~0. 5 – 2. 0 ke. V/n → acceleration to high energies (up to 500 Me. V/n and higher) - during solar flares (impulsive SEP event, heavy ion rich) - by shocks associated to CMEs (gradual SEP event, proton rich) SPENVIS -4. 5 5
Radiation environment (3/4): Trapped particles § § § Electrons : - 0. 04 – 7 Me. V - L = ~ 1. 5 (inner zone) and 2. 8 < L < 12 (outer zone) → highly dynamic - solar wind, ionosphere Protons : - 0. 04 – 500 Me. V - 1. 5 < L < 2. 5 - cosmic ray albedo neutron decay SAA: South Atlantic Anomaly / Southeast Asian Anomaly Polar horns SPENVIS – 4. 5 E. J. Daly, 1996 6
SPENVIS -4. 5 7
Radiation environment (4/4): Secondary particles → interaction with s/c shielding material Secondary particle fluence energy spectra after 20 -mm aluminum shield for an incident trapped proton spectrum accumulated over one year. The spectra are from a 10 incident protons simulation. 8
→ interaction with atmosphere GCR and SEP flux satellite (GOES/ACE) data, observed during Halloween event 2003) propagated (with NAIRAS model) to top level atmosphere and cruise altitude (10 -12 km). (from C. Mertens, 2010) 9
MIT Open. Course. Ware 10
Radiation Effects Energy deposition → Dose in rads (M) or Gy: d. E/dm Space environment dose rate ~10 -4 – 10 -2 rad/s → low X fluence Ionisation Dose LET (linear energy transfer) Non-ionisation Dose NIEL (non-ionising energy loss) Long-term effects → degradation of performance Short-term effects → soft and hard errors 11
(Adams et al. , 1987) Summers, 1993. 12
Radiation Effects (1/4): Total Ionizing Dose (TID) ▪ cumulative long term ionizing damage due to the production of electron – hole pairs § effects: - build up of charges/defects → device degradation (e. g. Vth shift and increasing leakage currents) - DNA damage ▪ main source: > 0. 1 Me. V protons (trapped & solar), electrons (trapped) 13
Radiation Effects (2/4): Displacement Damage Dose (DDD) ▪ cumulative long term non-ionizing damage due to the production of Frenkel pairs (vacancies and interstitials) § effects: lattice defects → parametric degradation (optical devices) like Pout decrease of solar cells ▪ main source: > 150 ke. V (0. 3 – 5 Me. V for solar cells) electrons (trapped) > 1 Me. V (1 – 10 Me. V for solar cells) protons (trapped and solar) neutrons 14
SOHO’s Solar Array Degradation History Solar array degradation: Net loss in two week period 1. 1% 15
Radiation Effects (3/4): Single Event Effect (SEE) ▪ stochastic effect caused by the production of small, spurious charge pulses within electronics ▪ processes: - direct ionization by single particle (heavy ion) - induced ionization via nucl. reaction (proton & neutron) ▪ effects: → errors in memory devices like logic change (soft) and burn-out (hard) → lit up of pixels of CCD by creation of free charge → DNA damage § main source: > 10 Me. V/n protons (trapped & solar), heavy ions (GCR & solar), neutrons charge ~Z 2 H. Becker, et al, IEEE Trans. Nucl. Sci. , 49(3082), 2002 16
SOHO image: “snowing on 14 July 2000 October 1989 event Uo. SAT-2 ( polar orbit of altitude about 700 km) 17
Radiation Effects (4/4): S/c charging ▪ accumulation of electric charge on s/c surface from natural space plasma → surface charging – Main source : 0. 01 – 100 ke. V electrons ▪ accumulation of electric charge on internal dielectrics from penetrating high-energy electrons → internal dielectric charging – Main source: > 100 ke. V electrons (trapped) - “Killer electrons” ▪ effects: (breakdown) discharges 18
During substorms, a hot plasma is injected from the magnetotail into the nightside high-altitude equatorial regions. � The electrons gradient- curvature drift towards dawn and can dominate the charge balance on a vehicle � The hazard arises when adjacent surfaces rise to different enough potentials to drive a discharge � A discharge can introduce unintended signals of tens of volts amplitude in command power lines Surface damage in a C 2 MOS Capacitor (Image from JPL) High speed solar wind and killer electrons 19
Summary: Radiation Effects in Space Radiation Effect Impact on Mission Natural Variation in Environment Space Environment surface charging biasing of instrument readings power drain physical damage 0. 01 - 100 ke. V : electrons 0. 01 - 100 ke. V: electrons minutes surface dose changes in thermal, electrical, and optical properties UV, atomic oxygen, particle radiation minutes deep-dielectric charging electrical discharges causing physical damage >100 ke. V electrons hours total ionizing dose performance degradation loss of function loss of mission >100 ke. V : trapped protons and >100 ke. V: trapped protons and electrons, solar protons hours non-ionizing dose degradation of optical components and solar cells > 1 Me. V : trapped protons, solar > 1 Me. V: trapped protons, solar protons, neutrons days single event effects data corruption noise on images interruption of service loss of s/c > 10 Me. V/n : trapped protons, > 10 Me. V/n: trapped protons, solar protons, solar heavy ions, GCR heavy ions, neutrons days 20
http: //www. aero. org/publications/crosslink/summer 2003/02_table 1. html 21
Solar Storm: flare, SPE, CME Enhanced EM Radiation (X, EUV, radio, g) Arrival time: 8 min Effect duration: 1 -2 hrs → e- density in ionosphere → expansion atmosphere • hf radio blackout • satcom inteference • radar interference • image interference • satellite drag High Energy Charged Particles (p+: 10 Me. V – 20 Ge. V) Arrival time: 15 min – few hours Effect duration: hours - days Enhanced B Field/ Plasma Clouds Arrival time: 2 – 4 days Effect duration: days → increased radiation exposure → induced currents → geomagnetic field distortion • high-altitude hf radio blackout • high-altitude aircraft radiation • satellite desorientation • s/c electronics damage • s/c solar panel degradation • false sensor readings • launch payload failure • human cell damage • ozon layer depletion • hf radio blackout • shift of outer radiation belt • s/c charging • radar false targets • satcom interference • oil and gas pipeline corrosion • electrical power blackouts 22
Threat matrix ‘Solar storm threat analysis’ by J. A. Marusek (http: //www. breadandbutterscience. com/SSTA. pdf) 23
References. § § § E. G. Stassinopoulos et al. , “A systematical global mapping of the radiation field at aviation altitudes, Space Weather, E. G. Stassinopoulos et al. , “A Vol. 1, No. 1, 1005, 2003. Adams, Jr. , et al. , “A comprehensive table of ion stopping powers and ranges”, NRL Memorandum Report, 1987. June, I. , et al. , “Proton Nonionising IEEE Transactions on Nuclear Science, June, I. , et al. , “Proton Nonionising Enegy Loss (NIEL) for Device applications”, IEEE Transactions on Nuclear Science, Vol. 50, No. 6, Dec. 2003 June, I. , et al. , “Electron Nonionising IEEE Transactions on Nuclear June, I. , et al. , “Electron Nonionising Enegy Loss (NIEL) for Device applications”, IEEE Transactions on Nuclear Science, Vol. 56, No. 6, Dec. 2009 C. J. Mertens et al. , “Geomagnetic influence on aircraft radiation exposure during a solar energetic particle event in C. J. Mertens et al. , “ october 2003, Space Weather 8(S 03006): doi: 10. 1029/2009 SW 000487 (2010 a) G. P. Summers, Damage Correlation in Semiconductors Exposed to Gamma, Electron, and Proton Radiations, IEEE Trans. Nuc. Sci. 40, pp. 1300, 1993. Trans. Nuc. 24
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