how to obtain more detailed info when particles get lost?

[Shichang]

Hi, everyone. Here are two problems in ring tracking:

• Is there any way to obtain the centroid or coordinate data before the particle get lost? In &run_setup there is indeed losses to record the data on lost particles, but if I want to obtain the specific data at the elements before the particle get lost in last turn, is there any way in ELEGANT to make it?

• The common sense is that the addition of RF and synchrotron radiation will make DA shrink, is this tenable when using &find_aperture?

Thanks a lot!

Jiang

[michael_borland]

Jiang,

The only way to record particle coordinates sometime before they are lost is using a WATCH element with MODE="coordinate". This will give coordinates at a specific element. You can reduce the quantity of data by using the START_PASS parameter to only log data for later turns.

elegant will correctly show the effect of RF and synchrotron radiation on the dynamic aperture when using the find_aperture command. I'm not sure I agree that this will always produce a smaller DA. It probably depends on the lattice.

--Michael