2023-01-26

Discussed pros/cons of shaker vs scraper for beam killing with Ishi-san

  • Shaker more reliable at killing beam (? -- unsure)

  • Scraper as used before now has Emi's WSM mounted to it. This cannot be used to kill the beam

  • Alternative scraper is in the middle of a magnet - not possible to use scintillator to image beam loss

  • Shaker has a perspex window -- scintillator can be used to gauge beam loss

  • We think shaker is likely to work better with a bunched beam -- we are developing a rebunch and flat-top AWG script for each debunch routine.

  • Later today we will take schottky measurements and use the RF shaker to remove any remaining beam


09:56 Emi is taking background/noise data for WSM

10:24 begin Schottky tests

  • taking new noise data for all RF programmes with no beam. tora bpm is plugged in - scope trigger 31.775ms 5ms/div

  • The new RF scripts are now include a capture toa 4kV stationary bucket with 2ms flat top to allow the RF shaker to kick the beam out, See an example of the awg script below

11:05 beam on and set up RF shaker timing

11:12 Steering magnet in the injection line has gone down.

11:24 using the KURNS nominal RF program to get everything working properly


13:31 Ion source settings changed. Intensity seems much greater. Large amount of parameters may have changed - need to reconfigure most things for new settings

  • set shaker timing into recapture/flat top region

    • Shaker timing - 58.1ms with RF offset 2.149ms

  • set shaker position such that we see beam loss/scintillator sig in the recapture area

    • Could be difficult to see the loss on the scintillator but we can see a clear drop on the FAB signal with the shaker

    • First we test shaker performance in acceleration region. We can see from the FAB signal that the beam is killed efficiently. - shown by pictures on scope

    • Shaker frequency on AWG set to 3.555 522 521 972 66MHz

    • Shaker position 517mm / +0180700

    • 14:40 save data showing FAB beam loss as a result of the shaker data file master file number 8, USB file number 5

    • Take schottky data

15:30 Emi WSM tests

  • Visible peak in WSM data that moves in time with WSM position and disappears when beam is off

  • Corresponding signal can be seen on scintillator (?)

16:10 reboot oscilloscope and resume tests

16:42 WSM measurements finish.

  • Data was looking good up to 190mm

  • Peak disappeared c.210mm position?

17:00 Move onto taking data for the extra schottky scripts

Took data of the nominal KURNS RF program but using an AWG script made with shinji's python script

Issues compiling tmp_12_3_3_2_30_2_3_2_2_3_2_2_0.055065_m2.85.equ -- unsure why.

  • Maybe not enough memory available on the disk? Problem seems to persist after deleting old programmes

  • All 'Double Peak' .equ files will not compile

c. 17:20 WSM measurements resume

We will very quickly take some tomography data instead.

  • Generated AWG script to take stationary bucket tomography data sequentially at: 4kV; 3kV; 2kV; 0.9kV

17:53 Also took data for the following RF program