Simulation of Low-Earth-Orbit Radiation Environments with a 5 to 120 MeV Proton Cyclotron Beam Using a Proton Beam Modulator

Suter, Joseph J.; Cloeren, J.M.; Norton, J. R.; Kusnierkiewicz, David Y.; Koehler, Andreas

doi:10.1109/tns.1987.4334799

Cited by 12 publications

(4 citation statements)

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“…Figure 7 ͑top͒ shows the overlapping between the common-emitter collector I-V characteristics of the reference DHBTs and the DHBTs irradiated with 2 ϫ 10 11 cm −2 protons and the exposure with this fluence ͑5 MeV͒ of protons is equivalent to around 40 years of exposure in low Earth orbit. 10 There was only minimal degradation of increasing output conductance and decreasing early voltage due to the decrease in the effective base resistance resulting from the traps created by the proton irradiation. However, for the higher fluences, more noticeable damage was observed, as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The degradation mechanism was dominated by the displacement damage in the base-emitter and base-collector junction space charge regions as well as the neutral base region gives rise to an increased recombination currents in both E-B and B-C junctions. 10 The increase in the base current for the proton-irradiated DHBTs also degraded the common emitter current gain. Figure 6 ͑top͒ shows the Gummel plots before and after the proton irradiation, while the bottom plot shows commonemitter current gain as a function of the collector current.…”

Section: Resultsmentioning

confidence: 99%

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Proton irradiation effects on Sb-based heterojunction bipolar transistors

Kim

et al. 2009

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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In 0.52 Al 0.48 As ∕ In 0.39 Ga 0.61 As 0.77 Sb 0.23 ∕ In 0.53 Ga 0.47 As double heterojunction bipolar transistors (DHBTs) were irradiated with 5MeV protons at fluences from 2×1011to2×1015protons∕cm2. The radiation produced significant increases in generation-recombination leakage current in both emitter-base and base-collector junctions. The DHBTs irradiated with a dose of 2×1011cm−2, which was equivalent to around 40years of exposure in low Earth orbit, showed minimal changes in the junction ideality factor, generation-recombination leakage current, current gain, and output conductance. The InAlAs∕InGaAsSb∕InGaAs DHBTs appear to be well suited to space or nuclear industry applications.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Proton irradiation effects on Sb-based heterojunction bipolar transistors

Kim

et al. 2009

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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“…A quantitative study of a lowearth orbit led to a proton-radiation model and the development of tests to simulate proton radiation using the Harvard University cyclotron [4]. A range modulator was designed for a specific curve of dose versus penetration depth in materials, so that protons could be deposited at specific depths in the piezoelectric resonator.…”

Section: A Bstructmentioning

confidence: 99%

“…This cyclotron accelerates protons to a maximum energy of 160 MeV [4]. The kinetic energy levels selected covered the 70-120-MeV range.…”

Section: Proton Radiation Studiesmentioning

confidence: 99%

Low-Earth-orbit proton and gamma ionization effects in piezoelectric alpha quartz crystal resonators

Suter

1990

IEEE Trans. Nucl. Sci.

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A bstructThe susceptibility of alpha quartz piezoelectric resonators to ionizing radiation manifests itself as frequency shifts. These frequency shifts degrade the performance of on-board satellite timing, navigation, and communication systems. Although , radiation shielding reduces this effect, high-energy protons (E > 65 MeV) can still interact with the piezoelectric quartz crystal lattice. The magnitude of the frequency shift in piezoelectric resonators is a function of dose and dose rate and also of the particle kinetic energy. Experiments showed that proton radiation represents the greatest hazard to piezoelectric quartz crystals. Electron radiation in low-earth orbits can be shielded by using approximately 3 gm/cm' of equivalent aluminum shielding. The radiation shields developed for these crystal resonators comprised low and high Z-shielding materials that reduce the amount of bremsstrahlung generated by the electrons. However, the magnitude of the proton radiation cannot always be reduced by shields because of weight considerations. Therefore, a study was initiated to investigate the interaction of proton radiation with the piezoelectric quartz crystals.These findings led to a study of the basic susceptibility mechanism in piezoelectric quartz crystal resonators and the development of low-earth-orbit radiation simulation tests using a proton cyclotron. The results of these studies are reported in this paper.To simulate the proton-radiation environment encountered by quartz crystals in space, one must model the energy spectrum of the proton radiation. A quantitative study of a lowearth orbit led to a proton-radiation model and the development of tests to simulate proton radiation using the Harvard University cyclotron [4]. A range modulator was designed for a specific curve of dose versus penetration depth in materials, so that protons could be deposited at specific depths in the piezoelectric resonator. Tests showed that the frequency shift per rad increased linearly as a function of proton kinetic energy over the 50-to 150-MeV range. Typically, the frequency shifts in the AT piezoelectric resonators were of the order of parts in IO " per rad for 100-MeV protons. I present below a modest explanation of this phenomenon in terms of the interaction of ionizing radiation with impurities in the crystal lattice and interface boundaries. I. INTRODUCTION 11. RESONATOR RADIATION STUDY The susceptibility of piezoelectric quartz crystal resonators to low-earth-orbit ionizing radiation degrades the performance of satellite communication systems. Previous studies have attempted to establish a relationship between the basic piezoelectric properties of quartz and its radiation response [l]. Some of these studies used the results of high dose (10 krad [Si]) tests to extrapolate the response of piezoelectric resonators to smaller doses (100 rad [Si]) encountered in low-earth orbits. Studies performed at The Johns Hopkins University Applied Physics Laboratory showed that the response of piezoelectric resonators to low do...

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