Harry Sandman – 2013

University of Surrey

During the last year I have been working in the Vulcan Laser Target Areas at the Rutherford Appleton Laboratory for the sandwich year of my physics degree. The Vulcan Laser is a pulsed Neodymium doped glass laser, which is capable of reaching Pettawatt level energies over a pulse duration of 500fs. This equates to delivering 10000x the power of the national grid over a fraction of a second. This level of intense electromagnetic energy (light) can strip electrons from atoms, ionising them, which creates the 4th state of matter, Plasma. Plasma is the most abundant state of matter in the universe, the matter in our solar system is 99.86% plasma, all of which is contained in the sun where solids, liquid and gases only account for 0.14%. We understand very little about plasma because creating the conditions where it exists on earth is extremely difficult. Amongst other things the Vulcan Laser is used to research this 4th state of matter, nuclear fusion reactions powered by lasers and how light and matter interact with each other.

Vulcan LazerAbove is an image I took of the plasma generated by the laser in the target chamber during an experiment. Every time the laser creates plasma it becomes the hottest place in the solar system for a fraction of a second, as long as no other High Power Laser system is firing at the same time. The image view point is looking down below on a plasma generated in the Target Chamber from a laser target interaction which is under vacuum. The image doesn’t represent the real colours present as the filtering and image recombination techniques that I used changed them. The filter used was specifically to block out the Laser light (as the laser is so bright that it would have over saturated the image and could have destroyed the CCD on the SLR camera) so you cannot see the Laser Beam in the Photo. The target that was shot in this photo was a small piece of metal, though targets can range from simple to complex shapes made out different materials and can even be jets of gas. The blue area in the image is the plasma interaction, whilst the straight blue lines are hot bits of the metal target which have been shot out at very high speeds during the interaction.

Over the last year some of my jobs have been to help set up experiments for visiting scientists, running detectors during experiments to help collect data, ordering and maintaining equipment, developing and testing new diagnostic equipment and helping run tours and outreach events around site. I was heavily involved in one of the experiments during February 2013.

This experiment was specifically trying to optimise a laser driven x-ray source to be developed into a portable x-ray source to use in radiography.

I was given a prototype large area flat panel scintillating array (x-ray detector) to test on this experiment. The experiment showed that this design works so then my job for the next few months was to test the crystals to try and make the detector as efficient as possible for the next version of the design.

This year has been an amazing experience in my life actually getting a chance to see how a real physics lab operates and to give me an insight into what life as a physicist is actually like and from what I’ve seen it’s a good one.

Comment by Editor: I was delighted to be shown around the Rutherford Appleton Laboratories by Harry and several undergrads and postgrads earlier this year. The array of buildings and laboratories is breathtaking and the workers there are among the brightest of the bright. This is frontier science and Harry realises that he was privileged to work there for a whole year. He also recognises the financial help the OWMT gave him in the purchase of a laptop computer.

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