Cockcroft Institute, Warrington, Cheshire, United Kingdom
The University of Liverpool, Liverpool, United Kingdom
Gas targets are important for a number of accelerator-based applications, in particular as cold targets for collision experiments and beam diagnostics purposes where gas jets have been successfully used as least intrusive beam profile monitors, however, detailed information about the gas jet is important for its optimization and the quality of the beam profile that can be measured with it. A laser velocimeter shall be used for an in-detail characterization of atomic and molecular gas jets and allow investigations into the jet dynamics. Existing methods are currently not efficient enough, hard to build, and rather expensive. A laser velocimeter based on the self-mixing technique can provide unambiguous measurements from a single interferometric channel, realizable in a compact experimental setup that can be installed even in radiation-exposed environments. In this contribution, an introduction to the underlying theory of self-mixing is given, before the design and functioning principle of the velocimeter is described in detail. Finally, preliminary experimental results with different solid targets are presented and an outlook on measurements with fluid and gaseous targets is given.
