Search found 164 matches
- Wed Feb 23, 2022 12:21 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests + 2021/22 YETS
All sectors cold, powering tests ongoing. After cavern closure (24th March) Sector 23 needs a new magnet training campaign: ~20 quenches, 2 weeks estimated, then ready for beam injection.
- Wed Feb 02, 2022 2:19 pm
- Forum: ALICE
- Topic: Tonga volcano eruption detected by ALICE DCS
- Replies: 1
- Views: 6885
Tonga volcano eruption detected by ALICE DCS
A nice demonstration of gas-filled particle detectors fulfilling a secondary/unintended function as barometers
https://alice-collaboration.web.cern.ch/node/35254
https://alice-collaboration.web.cern.ch/node/35254
- Tue Feb 01, 2022 7:49 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests + 2021/22 YETS
Here's my cartoon guess of what happened:
Essentially, the finger must have buckled somewhat at low temperature, then at the warm-up in Feb 2019, it was bent even further by the gap closing due to thermal expansion.- Tue Feb 01, 2022 7:48 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests + 2021/22 YETS
Here's a description of RF fingers from the ESRF website To absorb chamber-to-chamber misalignment and thermal expansion, [...], bellows are used to inter-connect a large number of chambers along the ring circumference. These bellows, however, are seen as resonant cavities by the beam hence breaking...
- Tue Feb 01, 2022 1:23 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests + 2021/22 YETS
Since we're (slowly) discussing YETS, I've added it to the topic. I suggest making a new thread "2022 operations" in March
- Tue Feb 01, 2022 1:21 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
Here is the aforementioned buckled RF finger found in 21L3
- Wed Dec 29, 2021 10:27 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
Beam test summary in these slides from Evian: https://indico.cern.ch/event/1077835/co ... s/4533367/
- Wed Dec 29, 2021 10:23 pm
- Forum: The Accelerator
- Topic: Evian Workshop 2021
- Replies: 1
- Views: 4252
Evian Workshop 2021
In November there was the "Evian" Workshop (actually held at CERN due to COVID)
Slides available here: https://indico.cern.ch/event/1077835/timetable/
For the impatient, I recommend checking out the summary talk at the end.
Slides available here: https://indico.cern.ch/event/1077835/timetable/
For the impatient, I recommend checking out the summary talk at the end.
- Tue Nov 09, 2021 1:07 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
The "ULO" has been identified as a buckled RF finger, so sector 23 will be warmed up for an intervention. This delays the restart by several weeks. (However, better to catch it now than then!)
- Tue Nov 02, 2021 1:52 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
Highlights from the beam tests:
- High machine availability throughout the tests (~90%)
- 40 hours of stable beams over 5 nights (6 hours planned)
- All key instruments working, mostly from day 1
- ULO found at 21L3
- Opportunistic ramp to 3.5 TeV with pilot beams
- Tue Nov 02, 2021 1:14 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
Aperture scans found a "unidentified lying object" (ULO) at 21L3. A bump of a few mm is sufficient to clear it with no problem.
This mirrors the 2015 post-LS1 commissioning, where a ULO was found at 15R8, which turned out to be a piece of plastic
This mirrors the 2015 post-LS1 commissioning, where a ULO was found at 15R8, which turned out to be a piece of plastic
- Wed Oct 27, 2021 8:08 am
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
Now stable beams!
- Tue Oct 26, 2021 11:55 am
- Forum: New Users Start Here
- Topic: hi
- Replies: 3
- Views: 6809
Re: hi
Welcome. I did see you pop in to the IRC channel the other day. Be aware that it moves fairly slowly (at the moment dominated by LHC comments) but there are a few human users who pay attention. I recommend using a bouncer or something like IRCCloud to stay connected.
- Tue Oct 26, 2021 11:50 am
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
First colliding single bunches at 450 GeV in 'adjust' at all IPs! First stable beams scheduled for tomorrow
- Tue Oct 19, 2021 4:00 pm
- Forum: The Accelerator
- Topic: October 2021 Beam Tests + 2021/22 YETS
- Replies: 34
- Views: 41948
Re: October 2021 Beam Tests
B1 was struggling a bit with high losses, but now it has made an appreciable number of turns (small blue blip!)
One probe in B2 now circulating stably
One probe in B2 now circulating stably