Configuration for the 2025 Special Runs: Proton-Oxygen, Oxygen-Oxygen, Neon-Neon and VdM scans
| |
Configuration for the 2025 Special Runs: Proton-Oxygen, Oxygen-Oxygen, Neon-Neon and VdM scans |
|
This document is work in progress and is being updated as information is collected and decisions are made.
| General beam properties | ||
|---|---|---|
| Beam energy | 6.8 ZTeV | |
| Beam 1 | Protons | |
| Beam 2 | Oxygen ions | |
| Max number of bunches per beam | 30-36 | Multi_36b_24_24_24_3bpi_12inj_800ns_bs1000ns_v2 is possible. Exact scheme to be defined/discussed. |
| Minimum Bunch spacing | 1 µs | Injections widely spaced to aid ATLAS IBL veto. |
| Proton bunch intensity | 9 x 109 protons per bunch | Setup beam limit is 3 x 1011 charges per beam (Hopefully a bit higher!) |
| Ion bunch intensity | 1.1 x 109 ions per bunch | Setup beam limit is 3 x 1011 charges per beam (Hopefully a bit higher!) |
| Proton beam emittance | 2.0 µm | Assumed from 2024 operation. |
| Ion beam emittance | 2.1 µm | Large uncertainty on this. |
| Hadronic cross-section | 0.45 barns | Can we agree on this value between the experiments? |
| IP1 (ATLAS/LHCf) | ||
| β* | 1 m | |
| Half crossing angle | -145 µrad | V (negative) is optimal for LHCf |
| Leveling value (pile-up) | µ = 0.01-0.03 | 8h at 0.01 then 0.03 |
| IP5 (CMS) | ||
| β* | 1 m | |
| Half crossing angle | 0 µrad | Plane is undefined but H (positive) |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.06 | To be determined depending on intensity. |
| IP2 (ALICE) | ||
| β* | 1 m | |
| Dipole polarity | + / + | No change during the run |
| External crossing angle | + 72 µrad | |
| Internal crossing angle | - 72 µrad | |
| Total half crossing angle | 0 µrad | |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.06 | To be determined depending on intensity. |
| IP8 (LHCb) | ||
| β* | 1.5m | |
| Dipole polarity | negative | No change during the run |
| External half crossing angle | -139 µrad | |
| Internal half crossing angle | + 139 µrad | |
| Half crossing angle | 0 µrad | |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.04 | To be determined depending on intensity. |
This assumes a squeeze for this energy is commissioned and that the lower center-of-mass energy is prefered.
| General beam properties | ||
|---|---|---|
| Beam energy | 5.36 ZTeV | |
| Beam 1 | Oxygen ions | |
| Beam 2 | Oxygen ions | |
| Max number of bunches per beam | 9 / 12 / 15 | Exact scheme to be defined/discussed. |
| Minimum Bunch spacing | Batches widely spaced to aid ATLAS IBL veto. | Injections of single bunches. |
| Bunch intensity | 3.6 x 109 / 2.7 x 109 / 2.1 x 109 ions per bunch | Setup beam limit is 3 x 1011 charges per beam (Hopefully a bit higher!) |
| Beam emittance | 2.1 µm | Large uncertainty on this. |
| Hadronic cross-section | 1.30 barns | Can we agree on this value between the experiments? |
| IP1 (ATLAS) | ||
| β* | 0.5 m | |
| Half crossing angle | 0 µrad | Plane is undefined but V (positive) |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.32 | To be determined depending on intensity. |
| IP5 (CMS) | ||
| β* | 0.5 m | |
| Half crossing angle | 0 µrad | Plane is undefined but H (positive) |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.32 | To be determined depending on intensity. |
| IP2 (ALICE) | ||
| β* | 0.5 m | |
| Dipole polarity | + / + | No change during the run |
| External crossing angle | + 91 µrad | Adjusted for lower beam energy |
| Internal crossing angle | - 91 µrad | Adjusted for lower beam energy |
| Total half crossing angle | 0 µrad | |
| Leveling value (pile-up) | µ = 0.2 | |
| IP8 (LHCb) | ||
| β* | 1 m | |
| Dipole polarity | negative | No change during the run |
| External half crossing angle | -176 µrad | Adjusted for lower beam energy |
| Internal half crossing angle | + 176 µrad | Adjusted for lower beam energy |
| Half crossing angle | 0 µrad | |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.16 | To be determined depending on intensity. |