Using Longitudinal Damper to Reduce Proton Abort Gap Losses
| Mail questions/comments to ronmoore@fnal.gov |
Last modified 06/16/2004 14:02 |
Guidelines for Operators
Let's define the quantity "longitudinal brightness" = T:SBDPIS / T:SBDPWS (units = E9 / ns).
The MACALC device T:PLBRIS now calculates this quantity for your convenience!
Use those intensity and bunch length parameters...other intensity or bunch length devices lead to different results.
*
Never turn OFF the longitudinal damper when the "longitudinal brightness" T:PLBRIS > 3900 E9/ns. Otherwise, you run the risk of a longitudinal instability and elevated proton abort gap losses.* If you want to try to reduce abort gap losses without using a collimator or other tuning, try reducing the longitudinal damper gain in 1 V steps according to the following criteria:
| T:PLBRIS = longitudinal brightness (E9/ns) | acceptable T:LDM1GF range/value (Volt) |
| > 4200 | -5 |
| 4100-4200 | -5 to -4 |
| 4000-4100 | -4 to -3 |
| 3900-4000 | -3 to -2 |
Don't reduce the damper gain when exceeds 4200 E9/ns. These values may change as we learn from experience.
| Mail questions/comments to ronmoore@fnal.gov |
Last modified 06/16/2004 14:02 |