EPAC will be capable of generating a range of particle beams, dependent on the set up of the interaction target, including protons, neutrons, ions and electrons, as well as X-rays and gamma rays. Electronics intended for radiologically harsh environments, such as space, can be exposed to these beams to test their radiation resistance and to examine the malfunctions induced by radiation.
Electronics are susceptible to damage from elevated levels of radiation.
This is of significant interest to the defence, aeronautics and space sectors, as any damage can lead to 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 (radiation intensity 20 times that of earth orbit) caused failure of the NASA’s Galileo mission to Jupiter.
High-powered lasers like EPAC can generate any manner of radiation required (protons, neutrons, ions and electrons as well as X-rays and gamma rays), making them well suited to radiation hardness testing. Proofs of concept performed at other CLF facilities have demonstrated that lasers can replicate the radiation environment of space.
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 that accumulate, degrading performance and eventually causing failure. Displacement damage is where a high energy particle (neutron or proton) knocks an atom out of place like a billiard ball.
Although lasers deliver a high dose over a short time, triggering different damage mechanisms to those associated with TID, 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 that are generated by interactions between lasers and solid targets can be directed onto sample instruments, which can then be studied to improve their performance in situ.
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 enabling electronics to be exposed 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 new ways ofunderstanding of the dynamic effects of radiation. Further investigation on the potential for the pulsed source is therefore recommended.