The Central Laser Facility (CLF) has high-power lasers that can hit targets with enough energy they instantly turn from a solid, stable matter into plasma- the forth state of matter. They can accelerate particles to travel faster than light through certain mediums. However, none of this would be possible without great numbers of minute, often complex, laser targets which are often completely hand-crafted.
Example of a typical target size.
(Credit: STFC)
Donna Wyatt.
(Credit: Helen Towrie, CLF)
Donna Wyatt, a target fabricator here at the CLF, is one of the most experienced practitioners in the field which requires highly specialised skills and many years of patient refinement.
Unlike most current target fabricators, Donna didn’t have a science background. With school failing to capture her interest, Donna took up beauty therapy at the suggestion of her mother. Although Donna was a natural, it wasn’t her passion.
It was a CLF engineer who suggested Donna apply for a job in the Target Preparation department, as it was originally called. “My first reaction was ‘Nope. No way could I do a job like that,’” Donna admitted with a laugh.
However, she did apply. Using her history of beauty therapy, she explained how she used very similar tools to target makers, for instance tweezers and brushes. She also reasoned that her experience with the delicate application of makeup would transfer over to target making. She proved to be a natural and 20 years on, Donna is one of the top target fabricators internationally, with involvement in multiple world-class experiments.
“At the time, laser targets were much larger and far simpler, so all I was asked to do was assemble some pieces together”, Donna explained. “Generally, they were 5 by 5mm foils.”
“But as technology has advanced and laser experiments have evolved, so have the targets. Now, targets are often modified per experiment and involve complex, miniscule components.”
Complex targets made by the target fab team.
(Credit: Chris Spindloe, CLF)
As Martin Tolley, group leader for Target Fabrication, pointed out: “Assembling mictrotargets is a particularly challenging process especially in response to the rapid demands of an evolving experiment. I rely heavily on Donna’s extraordinary skills and accumulated intuitive knowledge to deliver novel targets which enables new science.”
Since this is such an unusual and skilled job, it is always difficult to hire a new target fabricator. It is rare to find somebody comfortable working with objects of such a small scale.
Complex targets made by the target fab team.
(Credit: Helen Towrie, CLF)
When working at these tiny, sometimes nanoscale, sizes, very strange problems start to arise. For example, a single piece of dead skin under the microscope could be mammoth sized compared some of the components of your target. The subtle shake of your hands can be enough to make assembly an impossibility – to the point where target fabricators have to watch how much coffee they drink! When you work with things that are so small, every movement feels magnified, and the components you are working with do not care about gravity in the same way that larger objects do. Instead, what affects them is minute levels of static or the tiniest breeze.
“I think what keeps me interested is the fact that most of what we are doing has never been done before,” Donna said. “So the fact that I’ve made something from someone’s idea and it’s a one-of-a-kind first is what really keeps me going in this job… It’s very rewarding.”
Martin is clear when looking for new fabricators, having a science background is only a part of what he is looking for.
“The micro world is a counter-intuitive place. For sure, you can understand a lot of the physics intellectually, but it rapidly becomes very challenging and the most effective solutions are often highly craft-based. Only a few people have significant natural aptitude which can then be developed,” Martin explained.
It is clear that this job requires huge levels of unique skill, and as the world of high-powered lasers advances, so does the world of target making.
Learn more about Target Fabrication here.
