LHC 2010 - latest news

Week 36: Machine coordinators: Ralph Assmann, Roger Bailey

Main aims of the week:

• Inject 12 nominal bunches
• Ramp and squeeze bunch trains (150 ns spacing)

Statistics (from Mon 6/9/2010 07h to Monday 10/9/2010 07h)

	%	Mon	Tue	Wed	Thu	Fri	Sat	Sun
Beam availability	66.7	22.5	15.5	9.5	12.0	15.0	20.5	17.0
Set-up without beam	12.8	1.5	4.0	4.5	2.5	4.0	1.0	4.0
Faults	20.5	0.0	4.5	10.0	9.5	5.0	2.5	3.0
	100.0	24.0	24.0	24.0	24.0	24.0	24.0	24.0

Bunch train commissioning plan (version 09/09/2010)

LHC coordination vistar

Day	Summary	Link to report from morning meeting
Monday 13th September		Slides from 08h30 meeting
Sunday 12th September	07.00-10.00 Collimator problem 10.00-15.00 Setting up new ramp 15.00-24.00 Collimator set up 3.5 TeV with 170urad 24.00-10.00 Ramp and squeeze set up	Slides from 08h30 meeting
Saturday 11th September	Decision based on Friday's results Stick with 170urad Xing angle at injection. This will allow operation with any bunch spacing. Set up procedures to handle change of Xing angle through the operational cycle. 07.00-15.00 RF setting up and energy matching 15.00-23.00 Collimator set up 450GeV with wider TCTs 23.00-07.00 Qualification of collimators (loss maps)	Slides from 08h30 meeting
Friday 10th September	07.00-12.00 Hit a series of problems needing access 12.00-13.00 Recover and cycle 13.00-15.00 BPM interlock in point 6 15.00-20.00 Injection of 3 trains of 8 for beam-beam 20.00-02.00 Aperture studies 02.00-06.00 Test ramp Could reduce Xing angle to 80urad before affecting lifetime Could reduce Xing angle to 20urad, 1h lifetime Xing angle of 100urad OK for trains of 150ns Predicted aperture measurements in squeeze do not exist Measured n1=10-12 instead of predicted 7 Plenty of aperture in the triplets	Slides from 08h30 meeting
Thursday 9th September	07.00-09.00 Recover from 3.5TeV and setting up 09.00-14.00 Cryo problem 14.00-22.00 Injection/Injection protection 22.00-02.00 Access LHC then SPS problems 02.00-04.00 Ramp and squeeze with Xing angles 04.00-07.00 Beam lost PC trip. Access needed. Recover.	Slides from 08h30 meeting
Wednesday 8th September	07.00-12.00 Scheduled access before long weekend 12.00-14.00 Setting up 14.00-19.00 Technical faults then setting up 19.00-01.00 Injection/Injection protection 01.00-07.00 Ramp and squeeze with Xing, beta-beating	Slides from 08h30 meeting
Tuesday 7th September	07.00-13.00 Collimation at 450GeV short access for RF 15.00-20.00 Collimation at 450GeV 20.00-01.00 Transverse damper 01.00-07.00 Test ramp failed ..	Slides from 08h30 meeting
Monday 6^th September	02:00-04:00 Splash events for CMS: B1 - probe beam 04:00-10.30 Ramp 10 A/s (chromaticity, crossing angle non-closure, beta-beating) 12:00-19.00 Injection/Injection protection 19.00-23.00 Transverse damper 23.00-07.00 PLL commissioning / K modulation 450GeV	Slides from 08h30 meeting