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Pulsed valves: Fast Forward

Periodic Reporting for period 2 - PUFF (Pulsed valves: Fast Forward)

Reporting period: 2017-01-01 to 2018-12-31

Because our world consists of molecules, a better understanding of molecules and their interactions is key to answering many important questions such as the origin of life, improvement of catalysis, suppression of air pollution, etc. Researchers in the field of molecular physics and physical chemistry use fast pulsed valves to let a small 'puff' of gas into a vacuum apparatus in order to form a molecular beam for academic research on molecules and for diagnostic purposes such as breath analysis. These fast pulsed valves form a small market that was supplied worldwide in the past by only a few one-person companies. Many of these company owners are now retiring so the supply of pulsed valves has greatly decreased. Furthermore, improvements in pulsed valve performance are possible, making it possible to make the molecular beam apparatus smaller, cheaper, and more sensitive. In order to optimize use of a fast valve a suitable fast detector is needed, along with accessories for specialized work. Our goal in PUFF is to develop a reliable and improved fast pulsed valve with detector and accessories and make these available to the community as a product from a medium size business, Photek Ltd, Hasting UK. Three young scientists learned how to approach this development work, have made good progress in producing and improving fast pulsed valve, and are also using these products directly in their on-going PhD research projects.
The students became familiar with the prototype valve and how it is used for research. They learned the basics of how to build and test the valve while working at Photek, where they developed entrepreneurial skills and worked on many practical aspects including making the valves more chemically resistant, and extending the range of their operating temperatures. They have developed a much improved version which is available to interested users from Photek. During the course of this project the basic version of our fast valve became available to the public via two different university groups and a private company, thus solving the supply problem. The fast pulsed valve and beam detectors and other specialized accessories developed in this project have been explained to the community at several international conferences and will be described in detail in the open literature as part of the PhD research projects of the young scientists.
Three young scientists have received unique industrial-academic training and are learning to recognize other products for spin-offs. The scientific molecular beam community is now spared a huge effort in designing and building these fast pulsed valves themselves. A major advancement was the realization that the very short gas pulses now allow use of the valves without a separate source chamber, which greatly simplifies the typical apparatus, and also allows access to translationally cold but rotationally warm molecules. Another exciting development is the miniaturization of the fast gas pulse detector and combining it with velocity map imaging, which is the most advanced measurement technique of the last 30 years. The breakthrough science made possible by the fast pulsed valves and the new-generation beam detector should have important long term impact in the field of physical and analytical chemistry.
Fast ion gauge to optimize pulsed valve performance
Design of fast pulsed valve