This is of significant interest for defence, aeronautics and space sectors as it can cause malfunctions and failures. For example, a cosmic ray caused a malfunction in a commercial airplane in 2008 that resulted in serious injury to several occupants. And the high radiation environment in space caused failure of the Galileo mission to Jupiter (NASA); from a radiation intensity 20-fold that of earth orbit.
There are three broad classes of radiation damage that affect electronics; Total Ionising Dose (TID), Single Event Effects (SEE) and displacement damage. These can all alter the behaviour of microelectronic devices causing malfunction or failure. TID causes gradual changes within electronic structures which accumulate, degrading performance and eventually causing failure. Finally, displacement damage is where a high energy particle (neutron or proton) knocks an atom out of place like a billiard ball.
High powered lasers like EPAC can generate any manner of radiation required (protons, neutrons, ions, electrons as well as x-rays and gamma rays.) lending them well to radiation hardness testing. POC’s performed at the CLF have demonstrated that lasers can replicate the radiation environment of space. It is unlikely that EPAC will be able to analyse total ionising dose because lasers deliver a high dose over a short time triggering different damage mechanisms to those TID. However, EPAC will be able to play a role in investigating displacement damage and single event effects. For tests on displacement damage, protons or neutrons produced in EPAC generated by interactions between lasers and solid targets can be directed onto samples which can then be studied and developed to improve their performance.
Single event effects are those caused by single, high-energy x-rays or particles. This is a whole class of effects ranging from catastrophic failures such as single event burnout (SEB) to transient single event upsets (SEU) where a bit changes between a zero and a one (in either direction). For SEE tests, lasers can produce extremely energetic bursts of radiation in exceptionally short times. That means that they can expose an electronic to radiation pulses timed to coincide with events within the circuit for example the internal clock or while a file is being read. Application in this manner may open understanding of the dynamic effects of radiation in a new way. Further investigation on the potential for the pulsed source is therefore recommended.
