2025 Special Run Configurations

This page reflects the planned program in 2025. The times for scans are not updated after data-taking but some are based on previous years as indicated. In case of doubts do not hesitate to contact the LPC (or in case inconsistencies/mistakes are spotted).

van der Meer scan program

Step

Duration

Experiments activities

Remarks

Scans IP2/8 - VdM optics

~10h
(plus overhead)

ATLAS	CMS	LHCb	ALICE
0h15: DOROS Gain scan
head-on	head-on	1h50 : LHCb part 1 (SMOG-less + VELO fully closed)	no automatic leveling during scans
		1h40 : LHCb part 2 (SMOG-less + VELO open)
		2h40 : LHCb part 3 (SMOG + VELO open + LSC)
		ghost-charge	1h30 : ALICE part 1 (scan)
			1h30 : ALICE part 2 (LSC)
			1h00 : ALICE part 3 (scan with offset)
0h15: DOROS Gain scan

Filling Scheme:
Multi_74b_63_34_29_4bpi_23inj_1000ns_bs1000ns
Download

Scans should ideally happen in the same fill. If beams are dumped during a scan will need to repeat at least that full part

LHCb VELO Ghost charge measurements throughout ALICE scan, if possible.

Estimated times.

Scans IP1/5 - VdM optics

~22h45
(from 2024)

ATLAS	CMS	LHCb	ALICE
0h40 : head-on	0h40 : head-on	head-on, SMOG ON	ZDC in, +/+, no automatic leveling during the scans
4h00 : ATLAS VdM part 1		ghost-charge
head-on	5h30 : CMS VdM part 1
4h35 : ATLAS VdM part 2
head-on	6h50 : CMS VdM part 2
1h10++ : X-angle scan (several points between 0 & +160 urad)

Filling Scheme:
525ns_146b_144_35_20_8bpi_21inj_800ns_bs525ns
Download

Part 1 and 2 scans should ideally happen in the same fill. If beams are dump during a scan will need to repeat at least that full part

LHCb VELO Ghost charge measurements throughout the full program, if possible. Alternatively, at least at the beginning of parts 1 and 2.

Times are taken from 2024 running apart from X-angle scan.

Length Scale Calibration - VdM optics

~11h15
(from 2024)

ATLAS	CMS	LHCb	ALICE
6h00 : ATLAS LSC	head-on	head-on	no automatic leveling during scans
head-on	5h15 : CMS LSC	head-on	no automatic leveling during scans

Filling Scheme:
525ns_146b_144_35_20_8bpi_21inj_800ns_bs525ns
Download

Can ideally happen in the same fill as the previous one, if the beams are still good. If the fill is dumped, we need to re-fill with same filling scheme - require this to be with the same filling scheme as VdM.

Calibration Transfer fill with indivs ("CT-indivs") - physics optics

~7h
(plus overhead)

ATLAS	CMS	LHCb	ALICE
2h : immediate beam separation to µ=0.5 after optimisation. NO AFP insertion	head-on	head-on	no automatic leveling during scans
0.5h: maximal beam separation
1h : µ-scan
10min: maximal beam separation
15min: ß* levelling to 40-50 cm for maximum pile-up
1h : µ-scan
2h : head-on	1h : µ-scan

Filling Scheme:
525ns_140b_140_75_16_8bpi_19inj_800ns_bs525ns
Download
ß* levelling to target (40-50cm) only after first µ scan at 120cm. ATLAS ok to go up to pileup 68-70.

Calibration Transfer fill with trains+indivs ("CT-trains") - physics optics

>12h

ATLAS	CMS	LHCb	ALICE
15 min: µ-scan setup (separate immediately in IP1 to 3.5 sigma). AFP insertion.	head-on	Physics	Physics
2h: ATLAS µ-scan	head-on
head-on	2h: CMS µ-scan
30 min: Extended emittance scan	30 min: Extended emittance scan
Long decay of µ (remaining part of fill)	Physics

Filling Scheme:
25ns_2175b_2162_1914_2037_144bpi_20inj_3INDIVs
Download
ATLAS ok to go up to pileup 65.

van-der Meer scan parameters (copied from 2024 page)

Beam parameters for Calibration Transfer fill

Items	Remarks
Filling Scheme	525ns_140b_140_75_16_8bpi_19inj_800ns_bs525ns Download
Bunch Spacing	525 ns (minimal)
Injections	up to 2 batches of 4 bunches
Emittance in Stable Beams	as during physics fills
Intensity in Stable Beams	around 1.4x10¹¹ ppb
Brightness (bunch intensity / emittance)	as during physics fills

Beam parameters for scans in IP1 and IP5

Items	Remarks
Filling Scheme	525ns_146b_144_35_20_8bpi_21inj_800ns_bs525ns Download
Bunch Spacing	525 ns (minimal)
Injections	up to 2 batches of 4 bunches
Emittance in Stable Beams	3µm -- tolerable variations: 2.5µm to 3.5µm; some spread O(20%-30%) is welcome
Intensity in Stable Beams	0.8x10¹¹ ppb -- tolerable variations: 0.7x10¹¹ ppb to 0.9x10¹¹ ppb; some spread O(20%-30%) is welcome
Profiles	Preparation for VdM : Gaussian profiles which factorise the beam wrt H and V planes
Injection Optics	With crossing angle to not have problems with LR interactions when beams are large at injection

Beam parameters for Scans in IP2 and IP8 (optics applies to also scans in IP1/5)

Items	Remarks
Filling Scheme	Multi_74b_63_34_29_4bpi_23inj_1000ns_bs1000ns Download
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
IP8 beta*	24m in IP2/8 scan, 50m in IP1/5 scan
IP8 Dipole polarity	Down, +
IP8 external half crossing angle	-300 µrad; internal half crossing angle : -138 µrad --> effective half crossing angle at IP: -438 µrad.
IP2 beta*	19m
IP2 polarities	+ / + (Dipole and L3 magnet)
IP2 internal crossing angle	-72µrad
IP2 external crossing angle	145 µrad
IP2 effective crossing angle	+73µrad which is ok for using the ZDC
IP2 special request	TDIs fully open, BRANs retracted
Injection Optics	With crossing angle to not have problems with LR interactions when beams are large at injection

This web site is owned by the account lpc .