Making Vacuum Gauges Radiation Tolerant in High Radiation Environments

Electronics, when exposed to radiation, will degrade and eventually fail, but methods can be adopted to extend their life. A customer who was integrating one of our 801W units into a system required the device to pass a radiation life test.  It failed! Read on to see what we did to fix it…

Radioactive

Most semiconductor electronic components are susceptible to radiation damage; radiation-hardened components are often based on their non-hardened equivalents, with some design and manufacturing variations to reduce radiation damage susceptibility.

Under the effects of radiation, electronic components that aren’t hardened will:

  1. Creep
  2. Harden
  3. And become brittle leading to failure

Radiation hardening is the act of making electronic components and systems resistant to damage or malfunctions caused by ionizing radiation (particle radiation and high-energy electromagnetic radiation), such as those encountered in outer space and high-altitude flight, and around nuclear reactors and particle accelerators.

Ionization effects are caused by charged particles. A single charged particle can knock thousands of electrons loose, causing electronic noise and signal spikes. In the case of digital circuits, this can cause results which are inaccurate or unintelligible.

The best components to use in high radiation environments are passives and bipolar semiconductors. FETs can have problems, however some are suitable. Optoelectronics are the worst by far. The neutron dose affects optoelectronics by degrading LED output (damage to the semiconductor active layer, especially if the active layer is thick), and also can affect certain types of RAM. The radiation susceptibility in the standard 801W is likely not due to neutron damage, since it contains no opto-isolators.

We undertook a series of A/B testing to determine the best configuration of the product that would be both CE complaint and would pass radiation testing. The first 2 rounds of testing yielding failure points with the power supply and the op-amp. The 801W design was revised to include a different more radiation tolerant power supply and op-amp.

Results:

The third time was the charm, we were successful in implementing a vacuum gauge that was both CE compliant and survived radiation testing. These changes increased the performance and life expectancy of the original product. This radiation hardened vacuum gauge is the 801w-AC.

Get more details on our technique for making vacuum gauges and other scientific instruments radiation tolerant by accessing our case study.