Moving to higher energy

Moving to higher energy (preliminary)

From 3.5 TeV to 4 to 5 TeV. On the list:

Task	Comment	Time estimate
Hardware commissioning of main circuits to higher energy	Modification and testing of dump resistors Possible installation of snubbing capacitors for QPS Calorimetry and detailed QPS measurements - all sectors	~2 weeks
Qualification of machine protection to higher energy without beam	FMCMs, PIC, Collimators, TCDQ, BLMs, BPM interlocks, SMPs, RF, LBDS	In parallel with HWC
Operations dry runs of qualified sectors	Ramp, squeeze to/at higher energy	Sector by sector - after hand over from HWC

Re-commissioning of ramp and associated machine protection appropriate to the higher energy	With safe beam. Machine protection: LBDS, BLMs, RF	~1 week
Re-commissioning of squeeze	Could possibly ramp-squeeze-ramp which would avoid the need of recommissioning the 3.5 TeV squeeze.	~1 week
Optics and operations checks at high energy		~2 days
Re-optimisation of collimators		~4 days

Possible Strategy

Physics at 3.5 TeV at beta* = 2m, no crossing angle, 156 bunches maximum
For higher energy: ramp, squeeze at 3.5 TeV to 2 m., ramp to 4 -5 TeV.
Provide collisions at beta* = 2 m, no crossing angle, 156 bunches maxium - minimum effort if it works
Squeezing to 2 m at 3.5 TeV with the crossing angle on is a bit tight - would either need to re-commission squeeze at a higher energy or ramp-squeeze-ramp-squeeze. The last step fom 4 to 2 m say.

ML August 09