In the scope of Master’s thesis, an algorithm has been developed for calculation
of bunch-by-bunch lifetime in SSRF synchrotron and has been integrated
into the EPICS control system. Being familiar with the lifetime of each bunch
is a very important diagnostic parameter which provides a lot of information
about the quality of the synchrotron storage ring to the physicists. The
main obstacle in the development of the solution has been the speed electrons
travel with, which is very close to the speed of light. Consequently
that makes bunches to be very short. Smallest gap between two bunches is
therefore only 2 ns while the width is measured in a couple of hundreds of
picoseconds. The market does currently not provide equipment which could
acquire a sufficient amount of samples in one passing of the bunch to calculate
reliable lifetime information. Therefore, the solution had to be developed in
software layer with an algorithm that is fast enough to calculate the lifetime
in relatively short time. The calculation is executed based on the samples
acquired over many passings of a bunch which are then combined in a single
waveform. With this information, physicists and engineers in charge of
quality of the storage ring can more easily understand where the problems
lie and are consequently able to fix them.
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