RADIATION HARDENING BY TJ Scheele 27 April 2020

RADIATION HARDENING BY: TJ Scheele 27 April 2020 Abstract: Radiation can come from multiple sources and affect components in different ways. To increase the operational lifespan and reduce catastrophic errors of these affected components, different physical and logical manufacturing techniques are utilized. 1

OUTLINE What is Radiation Hardening? Where is Radiation Hardening necessary Effects of radiation on electronics Radiation Hardening techniques Radiation Hardening in nuclear power plants Military uses Cons of Radiation Hardening 2

WHAT IS RADIATION HARDENING? Goal of Radiation Hardening [1]: • Design and manufacture electronics to be resistant to ionizing radiation • Minimize damage or malfunctions. Ionizing Radiation: • Type of energy released by atoms that travels in the form of electromagnetic waves or particles. • These have the ability to detach electrons from atoms. 3

WHERE DO WE EXPERIENCE RADIATION PROBLEMS? Outer High Space Altitude Flight Nuclear Reactors Nuclear War 4

EFFECTS OF RADIATION ON ELECTRONICS Displacement Damage: • Caused by particles changing the lattice structure of a material • Can change electrical characteristics Ionization Damage: • High energy particle travels through a semiconductor and leaves an ionized trail behind it • Can move charge carrier around • Can create glitches and flipped bits 5

IONIZATION DAMAGE • Positive voltage on gate attracts electrons. • Holes accumulate at the silicon-Si. O 2 interface. • This positive charge buildup requires adjusting the gate voltage. [3] https: //www-physics. lbl. gov/~spieler/radiation_effects/rad_tutor. pdf, Page 6 6

HOW RADIATION CAUSES FAILURE Total Ionizing Dose (TID) Absorbed dose in a material from ionizing radiation over time. Effects: Leads to component degradation over time which can cause failures Creates excess holes which can alter device performance Note: 1 krad = 10 J/kg [4] Schrimpf, Fleetwood, Schrimpf, Ronald Donald, & Fleetwood, D. M. (2004). Radiation effects and soft errors in integrated circuits and electronic devices (Selected topics in electronics and systems ; vol. 34, pg. 552 ). Singapore ; New Jersey: World Scientific Pub. 7

HOW RADIATION CAUSES FAILURE Single Event Effects (SEE) Can cause a circuit to malfunction due to an ion passing through a sensitive node in a circuit. Can be non-destructive 8

SINGLE EVENT EFFECTS (SEE) [4] Schrimpf, Fleetwood, Schrimpf, Ronald Donald, & Fleetwood, D. M. (2004). Radiation effects and soft errors in integrated circuits and electronic devices (Selected topics in electronics and systems ; vol. 34, pg. 552 ). Singapore ; New Jersey: World Scientific Pub. 9

RADIATION-HARDENING TECHNIQUES Physical Manufacture devices using a better insulating substrate such as Silicon on insulator (SOI) or Silicon on sapphire (SOS) Install radiation shielding Can be very costly and heavy. 1 cubic foot of lead weights 708 lbs Mars Curiosity Rover weighs 1, 982 lbs [5] Able to apply high voltages to gate Logical Have redundant systems all perform the same calculations and compare results Example: NASA tested the software-hardened “Spaceborne” super computer for one year [6]. 0. 03% difference in performance relative to the ground computers running in parallel. 10

RADIATION HARDENING IN NUCLEAR POWER PLANTS • Extremely high radiation levels inside the reactor compartment (RC) • No integrated circuitry inside the RC • Use of gas filled proportional counters • Source Range • Intermediate/Power Range D 1 G: Ballston Spa, NY [7] 11

NUCLEAR POWER INSTRUMENTATION Source range • BF 3 detectors [7] • Surrounded by shielding to reduce gamma interference • Measures neutron flux when shutdown • . 1 to 1 million Counts Per Second (CPS) Intermediate and Power Range • Boron lined chamber • Surrounded by shielding • Measures neutron flux when operational [10] http: //nuclearpowertraining. tpub. com/h 1013 v 2/css/Figure-37 Power-Range-Channel-94. htm [8] https: //www. nuclear-power. net/nuclear-power-plant/nuclearreactor/nuclear-instrumentation/excore-nuclear-instrumentation/source-range -detectors/ 12

MILITARY USES OF RADIATION HARDENING High component overlap between military and space Military aircraft Military Satellites Still susceptible to high altitude nuclear detonations [11]. Low-Earth Orbit satellites at serious risk of exceeding total-dose limits. Currently 1, 468 out of 2, 218 satellites currently in orbit [14] Geosynchronous Orbit only at risk from >10 Mt detonations Most warheads in service around 0. 5 Mt [13] 13

NEGATIVE EFFECTS OF RADIATION HARDENING Expensive Higher power consumption Slower processing speeds Heavier weights 14

SUMMARY Radiation hardening is needed for devices exposed to high levels of radiation. Radiation There can cause components to fail early. are different methods for radiation hardening. The best way to deal with radiation is to not use components that are susceptible to radiation. High cross-over between military and commercial applications. Large trade-off between cost, reliability, and component weight 15

REFERENCES [1] Messenger, George C. "Radiation hardening". Access. Science. doi: 10. 1036/1097 -8542. 566850 [2] "Ionizing radiation, health effects and protective measures". World Health Organization. 29 April 2016. https: //www. who. int/news-room/fact-sheets/detail/ionizing-radiation-health-effects-and-protective-measures [3] https: //www-physics. lbl. gov/~spieler/radiation_effects/rad_tutor. pdf Page 6 [4] Schrimpf, Fleetwood, Schrimpf, Ronald Donald, & Fleetwood, D. M. (2004). Radiation effects and soft errors in integrated circuits and electronic devices (Selected topics in electronics and systems ; vol. 34, pg. 552 ). Singapore ; New Jersey: World Scientific Pub. [5] https: //mars. nasa. gov/msl/spacecraft/getting-to-mars/ [6] https: //www. nasa. gov/mission_pages/station/research/news/b 4 h-3 rd/eds-new-approach-radiation-hardening/ [7] https: //www. timesunion. com/business/article/This-isn-t-rocket-science-mdash-but-it-s-close-3593806. php#photo 3000379 [8] https: //www. nuclear-power. net/nuclear-power-plant/nuclear-reactor/nuclear-instrumentation/excore-nuclearinstrumentation/source-range-detectors/ [9] http: //nuclearpowertraining. tpub. com/h 1013 v 2/css/Source-Range-Nuclear-Instrumentation-87. htm [10] Conrad, E. , Gurtman, Kweder, Mandell, White, & Defense Threat Reduction Agency Fort Belvoir VA. (2010). Collateral Damage to Satellites from an EMP Attack. [11] https: //www. popularmechanics. com/military/a 23306/nuclear-bombs-powerful-today/ [12] http: //nuclearweaponarchive. org/Usa/Weapons/Allbombs. html [13] https: //www. ucsusa. org/resources/satellite-database#. WL 2 ly. PJCj. NE 16

MAIN CONCEPTS 1. There are two different kinds of radiation damage: Displacement and Ionization damage. 2. Radiation damage can be non-destructive or destructive 3. There a variety of radiation hardening techniques 4. Both military and commercial sectors require high reliability components for space applications 5. Radiation hardening does have some downsides. 17