Configuration for the 2024 lead-lead and pp-reference runs LPC home

Disclamer

The data in this table has been compiled in collaboration with the HI machine experts. This document is work in progress and will be updated whenever needed or useful.

Heavy Ion configuration and setup

• Intensity ramp-up requested by MPP
  • Intitial cycle performed with low intensity (filling schemes to be finalized).
    • 80b  : 1 fill; 2h Stable Beams
    • 250b  : 2 fills; more than  5h in Stable Beams 
    • 450b  : 2 fills; more than  5h in Stable Beams 
    • Check list needed to be completed before going to higher number of bunches
    • 850b  : 2 fills; more than  5h in Stable Beams 
    • 1240b  (full machine): corresponding to ~20 MJ of stored energy
  • ALICE will perform a polarity change roughly half way through the run. After the polarity change, MPP requires one cycle with low intensity followed by one fill of 450b and more than 2h  in Stable Beams .
• The ion run is expected to be done with 50ns bunch spacing, with slip stacking injection configuration.

LHC configuration

VdM scans

The VdM scans need to be done in the 100ns configuration. They will be done with regular physics optics and using a physics filling scheme.

After discussions in defining the filling scheme for the VdM scans, three filling schemes have been prepared.

Filling scheme optimised for IP2/8:

100ns_432b_204_324_301_28bpi_27inj_VdMPbPb Download

Filling scheme optimised for IP1/5:

100ns_432b_374_250_181_28bpi_27inj_VdMPbPb Download

Filling scheme equalized to all IPs (backup):

100ns_432b_290_264_256_28bpi_27inj_VdMPbPb Download

Filling schemes

The following AGKs can be assumed: 33201

Default filling schemes per intensity step, with 50ns slip-stacking and 56bpi, WITH INDIVs:

Default filling schemes per intensity step, with 50ns slip-stacking and 56bpi, NO INDIVs

Default filling schemes at full machine, with 50ns slip-stacking and 56bpi, NO INDIVs

Backup filling schemes with 50ns slip-stacking and 40bpi

pp reference run configuration and setup

• Intensity ramp-up requested by MPP
  • Intitial cycle performed with low intensity: 3b with SB declared and AFP inserted, followed by 12b, one fill with least 2h in SB.
    • 4b  : 1 fill; 2h Stable Beams
    • 75b  : 1 fill; 2h Stable Beams
    • 400b  : 1 fill; more than  5h in Stable Beams 
    • 1200b  : 1 fill; more than  5h in Stable Beams 
    • 2400b  : full machine and checklist
  • ALICE will perform a polarity change roughly half way through the run. After the polarity change, no MPP requirements

LHC configuration

VdM scans

The VdM scans need to be done with physics optics but VdM beams (INDIVs, low bunch intensity and large emittance). One full day (24h) allocated with contingency in the plan, with roughly 4-4.5hours scan per experiment.

The proposed filling scheme for the pp reference run (AGK 31481) has bunches separated by 525ns, with 2 batches of 4 separated by 800ns each:

525ns_122b_120_48_40_8bpi_17inj_bs800ns_VdMppref Download

Given the current constraints, the scan will be done in two fills: the first fill dedicated to ATLAS/CMS. The second fill dedicated to LHCb/ALICE, where LHCb will have to start with the SMOG OFF program. This ensures that LHCb can provide ghost-charge measurement during all the scans of the other experiments.

Filling schemes

The following AGKs can be assumed: 33211 (only for the full machine filling scheme)