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We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to-Digital Converters (ADCs), and Digital-to-Analog Converters (DACs), among others.
We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to-Digital Converters (ADCs), and Digital-to-Analog Converters (DACS), among others.
We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to- Digital Converters (ADCs), and Digital-to-Analog Converters (DACs), among others. T
This paper reports and analyzes recent single event effects (SEE) and total ionizing dose (TID) test results for the Analog Devices RH3845 synchronous current mode step-down controller. This device has been tested and evaluated for use in a harsh space radiation environment.
Teledyne’s PE99155 point-of-load buck regulator was tested to evaluate an applicationspecific question about the start-up behavior of the device. This test determined if accumulated total ionizing dose (TID) affected any start-up voltage transient characteristics. Testing was based on pass/fail criterial for the magnitude of the output voltage to ensure the safety of downstream electronics. Two sets of radiation tests were performed. The first group of PE99155s used a high dose rate (HDR) irradiation to 25 krad(Si). A second group of PE99155s used high dose rate irradiation to 30 krad(Si).
We present reliability data combined with total dose gamma radiation for one of the first commercially available resistive memory devices. These Tantalum Oxide (TaOX)-based resistive memory chips demonstrate operation in dynamic program and erase testing up to ~130 Krad(Si) of 60Co gamma dose. In static and unbiased conditions, the stored data in the memory cells were able to withstand up to 50Mrad(Si) of exposure. The access circuitry, though, seemed less robust to gamma radiation and was able to operate only up to a total dose of 3Mrad(Si). Post exposure reliability as indicated by endurance, cycling error rate, and data retention tests showed no detectable impact from the combination with prior gamma irradiation. Overall, the total dose radiation tolerance of the commercial TaOx-based resistive memory chip appears to be higher than flash memory chips and in agreement with prior tests conducted with single cell resistive memories.
The purpose of these tests was to characterize the susceptibility of the LSK389 and LSK489 Dual N-Channel JFET from Linear Systems to Single-Event Latchup due to heavy ions and to Total Ionizing Dose (TID) degradation at -65 °C and intermediate dose rate. The test was carried out to assess suitability of the amplifiers for the Ocean Color instrument (OCI) on the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) spacecraft.
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Passive radiation dosimeters were exposed aboard the Mir Orbital Station over a substantial portion of the solar cycle in order to measure the change in dose and dose equivalent rates as a function of time. During solar minimum, simultaneous measurements of the radiation environment throughout the habitable volume of the Mir were made using passive dosimeters in order to investigate the effect of localized shielding on dose and dose equivalent. The passive dosimeters consisted of a combination of thermoluminescent detectors to measure absorbed dose and CR-39 PNTDs to measure the linear energy transfer (LET) spectrum from charged particles of LET infinity H2O > or = 5 keV/micrometers. Results from the two detector types were then combined to yield mean total dose rate, mean dose equivalent rate, and average quality factor. Contrary to expectations, both dose and dose equivalent rates measured during May-October 1991 near solar maximum were higher than similar measurements carried out in 1996-1997 during solar minimum. The elevated dose and dose equivalent rates measured in 1991 were probably due to a combination of intense solar activity, including a large solar particle event on 9 June 1991, and the temporary trapped radiation belt created in the slot region by the solar particle event and ensuing magnetic storm of 24 March 1991. During solar minimum, mean dose and dose equivalent rates were found to vary by factors of 1.55 and 1.37, respectively, between different locations through the interior of Mir. More heavily shielded locations tended to yield lower total dose and dose equivalent rates, but higher average quality factor than did more lightly shielding locations. However, other factors such as changes in the immediate shielding environment surrounding a given detector location, changes in the orientation of the Mir relative to its velocity vector, and changes in the altitude of the station also contributed to the variation. Proton and neutron-induced target fragment secondaries, not primary galactic cosmic rays, were found to dominate the LET spectrum above 100 keV/micrometers. This indicates that in low earth orbit, trapped protons in the South Atlantic Anomaly are responsible for the major fraction of the total dose equivalent. c2002 Elsevier Science Ltd. All rights reserved.
One of the objectives of the AO 138-7 experiment on board the Long Duration Exposure Facility (LDEF) was a total dose measurement with Thermo Luminescent Detectors (TLD 100). Two identical packages, both of them including five TLD's inside various aluminum shields, are exposed to the space environment in order to obtain the absorbed dose profile. Radiation fluence received during the total mission length was computed, taking into account the trapped particles (AE8 and AP8 models during solar maximum and minimum periods) and the cosmic rays; due to the magnetospheric shielding the solar proton fluences are negligible on the LDEF orbit. The total dose induced by these radiations inside a semi infinite plane shield of aluminum are computed with the radiation transport codes available at DERTS. The dose profile obtained is in good agreement with the evaluation by E.V. Benton. TLD readings are performed after flight; due to the mission duration increase a post flight calibration was necessary in order to cover the range of the in flight induced dose. The results obtained, similar (plus or minus 30 percent) for both packages, are compared with the dose profile computation. For thick shields it seems that the measurements exceed the forecast (about 40 percent). That can be due to a cosmic ray and trapped proton contributions coming from the backside (assumed as perfectly shielded by the LDEF structure in the computation), or to an underestimate of the proton or cosmic ray fluences. A fine structural shielding analysis should be necessary in order to determine the origin of this slight discrepancy between forecast and in flight measurements. For the less shielded dosimeters, mainly exposed to the trapped electron flux, a slight overestimation of the dose (less than 40 percent) appears. Due to the dispersion of the TLD's response, this cannot be confirmed. In practice these results obtained on board LDEF, with less than a factor 1.4 between measurements and forecast, reinforce the validity of the computation methods and models used for the long term evaluation of the radiation levels (flux and dose) encountered in space on low inclination and altitude Earth orbits.
The evolution of highly miniaturized electronic and mechanical systems will be accompanied by new problems and issues regarding the radiation response of these systems in the space environment. In this paper we discuss some of the more prominent radiation problems brought about by miniaturization. For example, autonomous micro-spacecraft will require large amounts of high density memory, most likely in the form of stacked, multichip modules of DRAM's, that must tolerate the radiation environment. However, advanced DRAM's (16 to 256 Mbit) are quite susceptible to radiation, particularly single event effects, and even exhibit new radiation phenomena that were not a problem for older, less dense memory chips. Another important trend in micro-spacecraft electronics is toward the use of low-voltage microelectronic systems that consume less power. However, the reduction in operating voltage also caries with it an increased susceptibility to radiation. In the case of application specific integrated microcircuits (ASIM's), advanced devices of this type, such as high density field programmable gate arrays (FPGA's) exhibit new single event effects (SEE), such as single particle reprogramming of anti-fuse links. New advanced bipolar circuits have been shown recently to degrade more rapidly in the low dose rate space environment than in the typical laboratory total dose radiation test used to qualify such devices. Thus total dose testing of these parts is no longer an appropriately conservative measure to be used for hardness assurance. We also note that the functionality of micromechanical Si-based devices may be altered due to the radiation-induced deposition of charge in the oxide passivation layers.
One of the objectives of the AO 138-7 experiment on board the LDEF was a total dose measurement with Thermo Luminescent Detectors (TLD 100). Two identical cases, both including 5 TLDs inside various aluminum shields, are exposed to the space environment in order to obtain the absorbed dose profile induced. Radiation fluence received during the total mission length was computed, taking into account the trapped particles (solar maximum and solar minimum periods) and the cosmic rays; due to the magnetospheric shielding, the solar proton fluences are negligible on the LDEF orbit. The total dose induced by these radiations inside a semi-infinite plane shield of Al are computed with radiation transport codes. TLD reading are performed after flight; due to the mission duration increase, a post-flight calibration was necessary in order to cover the range of the flight induced dose. The results obtained, similar (+ or - 30 pct.) in both cases, are compared with the dose profile computation. In practice, these LDEF results, with less than a factor 1.4 between measurements and forecasts, reinforce the validity of the computation methods and models used for the long term evaluation of space radiation intensity on low inclination Earth orbits.
The purpose of this test was to validate the Intersil HSYE-117RH-Q flight lot for use in the fabrication of Europa Clipper Propulsion subsystem flight hardware. This test shall serve as the radiation lot acceptance test (RLAT) for the flight lot date with wafer lot number G3X3CQC and lot date code (LDC) 1830. Low dose rate (LDR) irradiations have been performed by the manufacturer, but only to 100 krad(Si). This test determined the enhanced low dose rate sensitivity (ELDRS) of the device up to the mission specific dose of 125 krad(Si).
Three read/write random access memories, AM91L24, HM1-6514, and MWS 5114, were subjected to total dose irradiation at three dose rates, with electrical testing after each increment of dosage. Annealing measurements were performed after the radiation tests were completed. The AM91L24 showed a strong dose rate effect and substantial post-irradiation annealing of radiation-induced damage. The dose rate effect was that a lower dose rate produced less net damage than an eqivalent total dose applied at a higher rate. The HM1-6514 showed essentially no dose rate effect and no annealing damage, and the MWS 5114 exhibited a moderate effect with some annealing. It was concluded that dose rate is an important parameter in radiation test procedures for MOS microcircuits and that annealing measurements may be important evaluation aids for such tests.
Analytical calculations are performed to determine the radiation dose rate and total dose to the crew of a gas-core nuclear rocket from the fission fragments located throughout the plume volume. The radiation dose from the plume fission fragments to two crew locations of 100 and 200 meters from the nozzle exit are calculated. It is found that, in the case of the most probable fission fragment retention time of 100 seconds, the crew must be protected from the radiation dose. Five centimeters of lead shielding would reduce the radiation dose by two orders of magnitude thereby protecting the crew. The increase in vehicle weight would be insignificant (7150 kg to a vehicle gross weight of 0.94 million kg).
Several different types of microwave transmission line phase shifters based on thin ferroelectic films have been developed at the NASA Glenn Research Center. These include a series of coupled microstrip lines, slotline incorporating Marchand balms, odd-mode coplanar strips, and hybrid devices incorporating a switch to toggle the output termination between an open and virtual short circuit. A review of the theory of operation of each of these devices will be presented along with measured performance. Also, devices of the first variety have been subjected to total dose (proton) radiation exposure using a 200 MeV beam energy with a total dose up to nearly 1 kRad (Si). Results of these radiation tests will be discussed.
A significant reduction in total dose damage is observed when bipolar integrated circuits are irradiated at low temperature. This can be partially explained by the Onsager theory of recombination, which predicts a strong temperature dependence for charge yield under low-field conditions. Reduced damage occurs for biased as well as unbiased devices because the weak fringing field in thick bipolar oxides only affects charge yield near the Si/SiO2 interface, a relatively small fraction of the total oxide thickness. Lowering the temperature of bipolar ICs - either continuously, or for time periods when they are exposed to high radiation levels - provides an additional degree of freedom to improve total dose performance of bipolar circuits, particularly in space applications.
The purpose of this test was to validate the Intersil HSYE-117RH-Q flight lot for use in the fabrication of Europa Clipper Propulsion subsystem flight hardware. This test shall serve as the radiation lot acceptance test (RLAT) for the flight lot date with wafer lot number G3X3CQC and lot date code (LDC) 1830. Low dose rate (LDR) irradiations have been performed by the manufacturer, but only to 100 krad(Si). This test was a follow-on to the original Radiation Lot-Specific Acceptance Testing (RLAT) performed on this LDC. Application-specific load currents were used for the line regulation and load regulation measurements. All other parameters were measured with standard bias conditions as specified in the datasheet.