The LHC Operator's Logbook is a gold-mine of information, but a little awkward to keep tabs on. So I propose that we post entries of interest to this thread, where they'll be more widely available.
Logbook entries are based on shift (starting date, day/evening/night) with timestamped entries, so an 0200 entry on night-shift is the next calendar day.
To access the log, sign up for an external account (explained elsewhere in this forum), go to the eLogbook page, click "signin" at the top left, select LHC OP from the pulldown. That's all explained elsewhere.
From the operator's log...
From the operator's log...
Last edited by mugwort on Tue Dec 08, 2009 4:47 am, edited 1 time in total.
7 Dec Night: beam running, wrong buckets
From the 7-Dec Night shift:
23:22 Precycle ongoing in all sectors. All vac valve open
23:53 All circuits finished precycle
00:54 1x1 bunch injected. Lifetimes ~ 25 hr, Problems with BPMs: not all reading out
... restarting BPM processes on Fesa servers for the BPMs
01:09 We proceed with the injection of the remaining bunches
02:41 LHCb call to say that the timing is off on both beams ... we start to look
03:29 Seems to be that the bunchs for both beams are shifted bach by ~ -128.3 25ns bunch crossings... the experiments are still taking data and collissions are in the right place. Seems to be that the an issue with the sychronisation of the LHC to the SPS at injecting multiple bunches. Phillipe from the RF is investigating
Note that the beam in bucket 1 appears to have been shifted to a position ~83 RF buckets in front of the abort gap. CMS is concerned about risks of beam in the abortgap; for now we stay with beam in but will go through the full Beam dump handshake when the lifetimes drop below 5 hrs
23:22 Precycle ongoing in all sectors. All vac valve open
23:53 All circuits finished precycle
00:54 1x1 bunch injected. Lifetimes ~ 25 hr, Problems with BPMs: not all reading out
... restarting BPM processes on Fesa servers for the BPMs
01:09 We proceed with the injection of the remaining bunches
02:41 LHCb call to say that the timing is off on both beams ... we start to look
03:29 Seems to be that the bunchs for both beams are shifted bach by ~ -128.3 25ns bunch crossings... the experiments are still taking data and collissions are in the right place. Seems to be that the an issue with the sychronisation of the LHC to the SPS at injecting multiple bunches. Phillipe from the RF is investigating
Note that the beam in bucket 1 appears to have been shifted to a position ~83 RF buckets in front of the abort gap. CMS is concerned about risks of beam in the abortgap; for now we stay with beam in but will go through the full Beam dump handshake when the lifetimes drop below 5 hrs