Difference between revisions of "Tune mode"
From GlueXWiki
(Created page with "Notes from Jay Benesch 10/31/13 ===Tune beam: at 60 Hz rep rate=== # Pulse structure #* 250 us of beam, bunches at 499 MHz, so 124,750 bunches #* 100 us of nothing #* 4 us of ...") |
(→Tune beam: at 60 Hz rep rate) |
||
| (2 intermediate revisions by the same user not shown) | |||
| Line 14: | Line 14: | ||
#* Crew chief permission is needed for higher current. One can run 200 uA tune beam. | #* Crew chief permission is needed for higher current. One can run 200 uA tune beam. | ||
#* 4 uA is the minimum needed for good readings on the old 4-channel BPM electronics. On SEE electronics, like that installed in most of the west arc this down and all the line to hall D, 1 uA tune beam reads fine. | #* 4 uA is the minimum needed for good readings on the old 4-channel BPM electronics. On SEE electronics, like that installed in most of the west arc this down and all the line to hall D, 1 uA tune beam reads fine. | ||
| + | |||
| + | |||
| + | [[Image:Tune mode time structure.png|thumb|600px|left]] | ||
Latest revision as of 11:49, 7 November 2013
Notes from Jay Benesch 10/31/13
Tune beam: at 60 Hz rep rate
- Pulse structure
- 250 us of beam, bunches at 499 MHz, so 124,750 bunches
- 100 us of nothing
- 4 us of beam, bunches at 499 MHz, so 1996 bunches
- 1.524% duty cycle.
The transit time per pass is a bit under 5 us so the blip at the end allows the BPMs to measure the five (six) passes in the linacs independently with adequate accuracy.
- Current:
- Tune beam is typically 4-8 uA.
- Crew chief permission is needed for higher current. One can run 200 uA tune beam.
- 4 uA is the minimum needed for good readings on the old 4-channel BPM electronics. On SEE electronics, like that installed in most of the west arc this down and all the line to hall D, 1 uA tune beam reads fine.
