LHC plans Email from T Camporesi CERN https

  • Slides: 9
Download presentation
LHC plans Email from T. Camporesi (CERN) https: //hypernews. cern. ch/Hyper. News/CMS/get/commissioning/1339. html LHC

LHC plans Email from T. Camporesi (CERN) https: //hypernews. cern. ch/Hyper. News/CMS/get/commissioning/1339. html LHC Early operation plans: • Thurs 18 Feb: First injection tests down the injection lines and up to the TED collimators at the entrance of LHC. Need to make sure that we lift “Injection Inhibit” • Mon 22 Feb: First beams circulation – LHC will deliver ~10 beam splashes for each beam when threading beam • Within a couple of weeks: 2 – 3 shifts of collisions at injection energy with interaction rates > 20 Hz • ~16 March: First collisions at 7 Te. V (date to be confirmed after beams have been ramped to 3. 5 Te. V) [few days warning needed by media] – While waiting for the ‘big media event, ’ work will be done towards squeezing the beams, even though the first collisions will be unsqueezed… – Beams will be circulated either separated at the IPs or injected into noncolliding bunches until that time… 17 Feb 2010 G. Rakness (UCLA)

What has been happening in Global Running? CMS Goals for Global Running… • Re-establish

What has been happening in Global Running? CMS Goals for Global Running… • Re-establish good detector performance • Get cosmic rays to understand where tracker is located • Take data in configurations for collisions Compare CSC timing relative to DT timing last week… • DT trigger from CRAFT ’ 09 (tuned for tracker with cosmic rays… – DT triggering on top and bottom – DT top delayed relative to bottom 17 Feb 2010 G. Rakness (UCLA)

CSC – DT relative timing at the Global Muon Trigger Blue circle = perfectly

CSC – DT relative timing at the Global Muon Trigger Blue circle = perfectly timed in… Monday 8 Feb 2010 Global Run 127062: • CSC in collision timing (left-over from 2009) • CSC triggering on Top and Bottom • CSC’s are early by >~ 1 bx 17 Feb 2010 G. Rakness (UCLA) 3

CSC – DT relative timing at the Global Muon Trigger Wed – Thurs, 10

CSC – DT relative timing at the Global Muon Trigger Wed – Thurs, 10 – 11 Feb 2010 Global Run 127581: • CSC in collision timing • CSC triggering on Bottom ONLY • CSC’s are early by ~ 1 bx 17 Feb 2010 G. Rakness (UCLA) 4

CSC – DT relative timing at the Global Muon Trigger Fri – Mon. 12

CSC – DT relative timing at the Global Muon Trigger Fri – Mon. 12 – 15 Feb 2010 Global Run 127902: • CSC in collision timing, delayed by 10 nsec • CSC triggering on Bottom ONLY • CSC’s are early by ~ 0. 4 bx Now CMS is happy. As of today, we moved back to collision timing not delayed by 10 nsec… 17 Feb 2010 G. Rakness (UCLA) 5

Building 904 Cosmic Ray Test Stand • Misha has a “large number” of DMB's

Building 904 Cosmic Ray Test Stand • Misha has a “large number” of DMB's and TMB's of which he doesn’t know their status… Need to test at 904 to verify that boards are OK before they go into the experiment. • I am going to meet with Misha Wednesday morning to get 904 going to take data to check out boards… – Experts have been notified that they will get called… • And Misha is making it his priority to track the boards better… 17 Feb 2010 G. Rakness (UCLA)

Comparator Hot Channels… • I pointed him to the TMB registers which record hot

Comparator Hot Channels… • I pointed him to the TMB registers which record hot channels as determined by TMB firmware – These will be stored in the database used by the “Expert System” beginning with EMUlib v 9. 6 (next version of online software) – My thought was to enable the automated masking in the configuration database after this storage begins (next week)… 17 Feb 2010 G. Rakness (UCLA)

Today the following came up… • Stan has been analyzing CFEB data from Amanda’s

Today the following came up… • Stan has been analyzing CFEB data from Amanda’s collision data, and finds that the is ~50 nsec too early, and needs… – CLCT pretrigger earlier – … together with the L 1 A earlier. . . • I need to explore the values… – cfeb[0 -4]_rxd_delay – L 1 A – CLCT pretrigger timing difference… 17 Feb 2010 G. Rakness (UCLA)

In addition… • I proposed at the CMS Run Meeting Jay’s idea to make

In addition… • I proposed at the CMS Run Meeting Jay’s idea to make a baseline measurement of the background neutron rate during collisions – Amount of background neutrons should scale with luminosity should be “zero” during cosmic ray running – CSC in “single-layer trigger” mode (in order to readout), but not included in the trigger – Estimate ~10 – 20 minutes per luminosity point – Tiziano was intrigued… – I need to do some work to update the Yellow Page to configure without writing the configuration to the user. PROM’s… 17 Feb 2010 G. Rakness (UCLA)