Cosmic Radiation Environment Dosimetry and Charging Experiment (CREDANCE)
PI: Dr. Clive Dyer, QinetiQ/United Kingdom
Objectives:
Characterize the energetic space radiation environment and its interactions with spacecraft
Provide data to other SET-1 experiments
Goals:
Provide data to improve radiation environment models and design tools
Demonstrate the value of a compact space weather monitor in operational spacecraft
Measurements:
Proton flux > 40 MeV per unit solid angle
Charge deposition in large silicon diodes arranged in telescopes. Pulse height analysis is used to obtain ion linear energy transfer (LET) spectra of heavy ions in the 100 MeV-cm2/g to 25000 MeV-cm2/g range
Threshold voltage shift as a function of time to measure total ionizing dose in silicon at 2 different shielding depths
Charging current at 3 different shielding depths to provide energetic electron flux measurements at 3 energies
Dosimetry Intercomparison and Miniaturization Experiment (DIME)
PI: Dr. Peter McNulty, Clemson University
Objectives:
Use five different COTS microdosimeters to characterize radiation induced total ionizing dose, displacement damage, and single event effects
Goals:
Provide data to permit appropriate dosimetry selection in future missions to characterize/resolve operational anomalies
Validate particle transport codes by varying shielding thicknesses on RADFETs
DIME Measurements:
RADFET – Radiation-Sensing Field-Effect Transistor
Threshold voltage shift as a function of time to measure total ionizing dose
EPROM - Erasable Programmable Read-only Memory
Threshold voltage shift as a function of time to measure total ionizing dose
Number of single event upsets as a function of time to measure rates as a function of radiation level
UVPROM – Ultraviolet erasable Programmable Read-only Memory
Charge stored on floating gates is neutralized with radiation exposure. Resulting bit flips reflect micro-dose deposited in gates
2 LET Spectrometers – Linear Energy Transfer Spectrometers
Pulse height spectra as function of time is converted to LET to measure ions including protons. Optimized for high and low LET ions.
OSL Films - Optically Stimulated Luminescent Films
Visible emission spectrum as a function of time gives sensitive measure of ionizing dose
Development of Space-Based Test Platform for the Characterization of Proton Effects and Enhanced Low Dose Rate Sensitivity (ELDRS) in Bipolar Junction Transistors
PI: Dr. Hugh Barnaby, Arizona State University
Objective:
Measure ELDRS (primary) and proton effects (secondary) in positive-negative-positive (PNP) bipolar junction transistors (BJTs)
Goal:
Improve understanding of the physics of ELDRS and thereby improve/validate ground testing protocol for linear bipolar technologies and reduce design margins
Measurement:
Base and collector currents for 24 COTS BJTs as functions of the emitter and gate voltages and time
COTS-2: Digital Technologies
PI: Robert Ecoffet, CNES/France
Objective:
Validate approaches to mitigate single event effects by comparing simulation techniques, performance models, and on-orbit data
Validate mitigation of single event effects during space weather events
Goal:
Increase reliability of COTS technologies for space applications and reduce design margins
Measurement:
Measure single event effects on COTS FPGAs, classify the event by event type, and determine if mitigation of the effect occurred without watchdog intervention
Radiation Shielding Performance of PolyRAD
(alternate experiment)
PI: Edward Long, Longhill Engineering
Objective:
Evaluate the space flight performance of spot shielding with polyRAD for reduction of total ionizing dose
Goals:
Reduction of mass margins, cost and radiation damage risk
Enable space flight use of advanced COTS microelectronics
Measurement:
Threshold voltage shift of RADFETs to measure total ionizing dose for 2 shielding configurations:
2-dimensional flat shape corresponding to top-side shielding
3-dimensional net shape representing device encapsulation |
