The data shown here is "work-in-progress"

 

The parameters on this page reflect the best current knowledge and will be regularly updated and changed accordingly. Please consider this when using these parameters for any estimate. In case of doubts do not hesitate to ask the LPC.

 

 

 

Contents

 

VDM scan 2022

Low-µ run for LHCf

90m run

 

 

 

 

AGK after TS1

It remains to be determined if a different AGK setting will be needed for the vdM and LHCf run (likely not).

VdM programme 2022

The following is largely based on 2018 procedures and expected to evolve in future discussions.

The VdM programme is scheduled to start after the 3b validation fill and vdM cycle validation after TS1 and will be interleaved with the LHCf low-µ run. This will probably fall on the weekend of the 17/9/2022 with . The programme consists of the following steps (no turn-around times taken into account here).

Maximum separation allowed by MPP: 2.5 nominal σ for each beam in one plane at a time. Separation in both planes at the same time are not allowed. The limits are given in terms of nominal emittance : ε_n=3.5µm. This means that the de-facto separation is larger since we in fact run with lower emittance (~2.3µm - to be updated). 

Step	Duration	Experiments activities	Remarks
3b validation fill - low ß* optics	30min	ATLAS CMS MPP head-on head-on 4min : emittance scan Go to Stable beams; RP insertion? (AFP or ALFA in IP1? PPS?); No ß* leveling	30min Stable Beams for MPP Need 3b fill with vdM optics as well for MPP?
Non-linearity measurement fill (3b - vdM optics)	2h	ATLAS CMS 1h   : scan of beam 1 No movement ("head-on") 1h   : scan of beam 2	Filling Scheme:   1-3 non-colliding nominals in each beam. No long-range anywhere Could potentially be done during final vdM cycle validation TBD if CMS would like to do the same type of scan
Calibration transfer fill (140b - low ß* optics)	4.5h	ATLAS CMS MPP 2h   : immediate beam separation to µ=0.5 after optimisation head-on CMS 1h head-on RP insertion 0.5h: maximal beam separation 1h   : µ-scan 1h   : head-on 45min : µ-scan ATLAS 1h head-on	Filling Scheme: Multi_525ns_140b_140_75_16_8bpi_19inj.csv Scheme optimised for few AGK changes (might change for 2022) No ß* levelling (stay at 60cm)
LHCf run (vdM optics)	2-4 days	See details below	Filling Scheme: Multi_525ns_152_150_0_0_8bpi_19inj.csv
LHCf removal	8 hours	Access to tunnel to extract LHCf detectors
Scans IP2/8	8h45min (plus overhead)	LHCb ATLAS ALICE 1h : LHCb part 1       2h : ATLAS Length scale calibration   2h15min : LHCb part 2          3h30min : ALICE scan	Filling Scheme: Multi_70b_58_20_22_4bpi_19inj.csv
Scans IP1/5	15h45min (plus overhead)	ATLAS CMS 1h : ATLAS part 1     3h30min : CMS part 1 3h : ATLAS part 2 (non-factorization)     1h30min : CMS part 2 2h : ATLAS part 3     3h30min : CMS part 3 1h ATLAS part 4     15min : CMS emittance scan & super separation (6 sigma total in x/y)	Filling Scheme: 525ns_140b_124_32_23_16bpi_11inj.csv ATLAS 1 2 and 3 4 need to be in same fill CMS: 1 and 2 need to be in same fill if beam is lost in cms part three, we need to refill
600b - ramp up fill	5h	ATLAS CMS MPP head on emittance scan 1h head-on each IP RP insertion ß* leveling to all ß* settings > 2h total	Filling Scheme: 25ns_603b_590_524_542_48bpi_17inj More special runs here?
Normal physics fill	optimal		Filling Scheme: Default 2022 full ring - TBA To be seen if additional intermediate fill needed as part of ramp-up

Beam parameters for Calibration Transfer fill

Items	Remarks
Filling Scheme	Multi_525ns_140b_140_75_16_8bpi_19inj.csv
Bunch Spacing	525 ns (minimal)
Injections	up to 2 batches of 4 bunches
Emittance in Stable Beams	tolerable variations: 2µm to 3µm
Intensity in Stable Beams	1.2x1011 ppb  --  tolerable variations: 1.1x1011 ppb to 1.25x1011 ppb;
Brightness (bunch intensity / emittance)	< 0.5 x 1011 ppb / µm

 

Beam parameters for Scans in IP2 and IP8

Items	Remarks
Filling Scheme	Multi_70b_58_20_22_4bpi_19inj.csv
Bunch Spacing	1000 ns (minimal)
Injections	up to 4 batches of 1 bunch ("traditional" VdM schemes)
Emittance in Stable Beams	3µm for LHCb;  >3µm for ALICE (second in scan programme)
Intensity in Stable Beams	0.7x1011  - 0.9x1011 ppb in LHCb 0.4x1011  - 0.9x1011 ppb in ALICE (Alice is second in the scan programme)
Profiles	Preparation for VdM : Gaussian profiles which factorise the beam wrt H and V planes
IP 8 Dipole polarity	+ / +
IP 8 external half crossing angle	145 µrad; internal half crossing angle : -75 µrad --> effective half crossing angle at IP: 70 µrad which is ok for using the ZDC.
Injection Optics	With crossing angle to not have problems with LR interactions when beams are large at injection
IP2 polarities	+ / + (Dipole and L3 magnet)
IP2 internal crossing angle	-75µrad
IP2 external crossing angle	145 µrad
IP2 effective crossing angle	+70µrad
IP2 y - vertex shift	-1 mm

 

Beam parameters for scans in IP1 and IP5

Items	Remarks
Filling Scheme	525ns_140b_124_32_23_16bpi_11inj.csv
Bunch Spacing	525 ns (minimal)
Injections	up to 4 batches of 4 bunches
Emittance in Stable Beams	3µm -- tolerable variations: 2µm to 4µm; some spread O(20%-30%) is welcome
Intensity in Stable Beams	0.85x1011 ppb  --  tolerable variations: 0.70x1011 ppb to 0.95x1011 ppb;  some spread O(20%-30%) is welcome
Profiles	Preparation for VdM : Gaussian profiles which factorise the beam wrt H and V planes
IP 8 Dipole polarity	+ / +
IP 8 external half crossing angle	145 µrad; internal half crossing angle : -75 µrad --> effective half crossing angle at IP: 70 µrad which is ok for using the ZDC.
Injection Optics	With crossing angle to not have problems with LR interactions when beams are large at injection
BGV measurements	Requested by CMS (to be followed up by LPC)

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Low-µ run for LHCf

The LHCf run is scheduled to start shortly after the first luminosity calibration related fills after TS1 This will probably start around of the 20/9/2022 with up to four days of data taking foreseen.

LHCf will take data with their detector in two different positions. AFP or ALFA roman pots to be inserted as well. The luminosity request is for about 40/nb per detector position. This will take about 26 hours of stable beam per position with 150 colliding bunches.

Beam parameters for LHCf run

Items	Remarks
Filling Scheme	Multi_525ns_152_150_0_0_8bpi_19inj.csv
Bunch Spacing	525 ns (LHCf could go to 200ns, but would require a different filling schemes)
Injections	up to 4 batches of 4 bunches
Emittance in Stable Beams	3µm
Intensity in Stable Beams	0.85x1011 ppb
Beam crossing in IP1	Vertical, downward
Luminosity leveling in IP1	Offset leveled to µ=0.02
Beam crossing in IP5	CMS requested to run with zero crossing - might do some luminosity-related scans

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90m run for TOTEM

The 90m run is scheduled for taking place after TS2 when the new T2 detector is installed, nominally around 10/11/2022.

The squeeze for this fill will be very long (40m - TBC) and might go to 120m to achieve the optimal pile-up level.

The TOTEM roman pots will be inserted close to the beam, so there will be no stable beam and beam should stay below "SETUP BEAM" limits (3x10¹¹ protons.

Beam parameters for TOTEM run

Items	Remarks
Filling Scheme	4 colliding bunches in IP1/5, all well separated
Emittance in Stable Beams	Ideally 3µm as otherwise need lower intensity or larger ß*
Intensity in Stable Beams	0.6-0.7x1011 ppb
Target pile-up level in IP6	µ=0.04-0.1 No offset leveling allowed
Beam crossing in IP5	Zero crossing
Target luminosity	About 1/nb - should take around 6 hours

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