Updated October 2026 · An overview for planning, not a substitute for the standard
What Test Method 1019 covers
MIL-STD-883 Test Method 1019 defines how to test microcircuits for total ionizing dose (TID) effects using a Co-60 gamma source. It sets out several test conditions. Condition A is the familiar high-dose-rate test, run at 50 to 300 rad(Si)/s, where a typical qualification dose is reached in minutes. Condition D is the low-dose-rate condition used for parts that may be ELDRS-susceptible.
Why a separate low-dose-rate condition exists
Many bipolar and BiCMOS linear and mixed-signal devices degrade more at low dose rate than at high dose rate for the same total dose. A high-dose-rate result can therefore understate how a part will behave in orbit. Condition D exists so that this sensitivity is measured directly rather than assumed away.
Condition D's rate is a test convention. Actual dose rates in orbit are typically far lower, so the low-dose-rate test is a practical compromise between realism and schedule.
How long a Condition D test takes
Duration is simply total dose divided by dose rate. At 10 mrad(Si)/s, every 10 krad(Si) takes about 11.6 days:
| Illustrative test target | Days at 10 mrad(Si)/s | Weeks |
|---|---|---|
| 10 krad(Si) | 11.6 | 1.7 |
| 20 krad(Si) | 23.1 | 3.3 |
| 30 krad(Si) | 34.7 | 5.0 |
| 50 krad(Si) | 57.9 | 8.3 |
| 100 krad(Si) | 115.7 | 16.5 |
Those figures are irradiation time only. Pre-irradiation characterization, interim readouts, any post-irradiation anneal and shipping all add to the calendar. Our duration calculator adds dose margin and anneal time and gives a completion date.
What a Condition D setup involves
- A stable Co-60 source position that can deliver a constant, low dose rate at the device location for weeks to months.
- A lead/aluminum (Pb/Al) filter box around the devices to reduce low-energy scattered radiation that would otherwise cause dose errors. ASTM E1249 addresses minimizing these dosimetry errors in Co-60 testing.
- Bias during irradiation as specified in the test plan. Bias condition can strongly affect results, and some programs test both biased and unbiased samples.
- Dosimetry to establish and verify the dose rate at the device positions, with calibration traceable to national standards.
- Electrical measurements before irradiation, at interim dose levels and after irradiation, within the time limits the method sets.
- Records of accumulated dose, interruptions, environmental conditions and chain of custody.
Anneal and rebound steps
Post-irradiation steps depend on device technology and the procedure you specify. Method 1019's extended rebound test, an additional dose followed by an elevated-temperature biased anneal, applies mainly to MOS devices. For bipolar ELDRS testing, follow the anneal requirements in your test plan and the current revision of the method.
Planning tips
- Reserve the window early. A Condition D exposure ties up a source position for its full length, so capacity is the usual constraint.
- Fix the test plan before booking: dose, rate, bias, sample size, readout points and anneal.
- Build bias boards for the full duration, including connectors and cabling that will run unattended for weeks.
- Plan interim readouts so a failing lot is caught before the full exposure ends.
- Add calendar margin for shipping, setup, dosimetry verification and post-irradiation work.
This page is a general overview for planning. Always work from the current revision of MIL-STD-883 Test Method 1019 and your program's requirements. Parapet Radiation Lab is a planned facility; testing is not yet offered.