Configuration for the 2025 Special Runs: Proton-Oxygen, Oxygen-Oxygen and Neon-Neon
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Configuration for the 2025 Special Runs: Proton-Oxygen, Oxygen-Oxygen and Neon-Neon |
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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 | |
| Nucleon-nucleon CoM energy | 9.62 TeV | |
| Beam 1 | Protons | |
| Beam 2 | Oxygen ions | |
| Max number of bunches per beam | 52 (48 colliding) | Multi_52b_32_32_32_4bpi_13inj_800ns_bs1000ns_Oxygen |
| Minimum Bunch spacing | 1 µs | Injections widely spaced to aid ATLAS IBL veto. |
| Proton bunch intensity | ∼ 2.3 x 1010 protons per bunch | |
| Ion bunch intensity | ∼ 2.3 x 1010 charges per bunch | |
| Proton beam emittance | 2.0 µm | Assumed from 2024 operation. |
| Ion beam emittance | ∼ 1.9 (H) / ∼ 2.2 (V) µm | |
| Hadronic cross-section | 0.45 barns | |
| IP1 (ATLAS/LHCf) | ||
| β* | 1 m | |
| Half crossing angle | -145 µrad | V (negative) is optimal for LHCf |
| Leveling value (pile-up) | µ = 0.01-0.03-0.2 | 2h at 0.2 then 8h at 0.01 then 0.03 for the rest |
| Peak pile-up | µ ∼ 0.44 | This is if head-on at the start of the fill. |
| IP5 (CMS) | ||
| β* | 1 m | |
| Half crossing angle | +60 µrad | H (positive) |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.5 | This is when head-on at the start of the fill. |
| 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) | µ = 0.05-0.1 | 0.05 in the first fill, 0.1 in the second fill. |
| Peak pile-up | µ ∼ 0.5 | This is if head-on at the start of the fill. |
| 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 ∼ 0.33 | This is when head-on at the start of the fill. |
| General beam properties | ||
|---|---|---|
| Beam energy | 5.36 ZTeV | |
| Nucleon-nucleon CoM energy | 5.36 TeV | |
| Beam 1 | Oxygen ions | |
| Beam 2 | Oxygen ions | |
| Max number of bunches per beam | 52 (48 colliding) | Multi_52b_32_32_32_4bpi_13inj_800ns_bs1000ns_Oxygen |
| Minimum Bunch spacing | 1 µs | Injections widely spaced to aid ATLAS IBL veto. |
| Bunch intensity | ∼ 2.3 x 1010 charges per bunch | |
| Beam emittance | ∼ 1.9 (H) / ∼ 2.2 (V) µm | |
| Hadronic cross-section | 1.30 barns | |
| IP1 (ATLAS) | ||
| β* | 0.5 m | |
| Half crossing angle | +100 µrad | V (positive) |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.2 | This is when head-on at the start of the fill. |
| IP5 (CMS) | ||
| β* | 0.5 m | |
| Half crossing angle | +100 µrad | H (positive) |
| Leveling value (pile-up) | No leveling | |
| Peak pile-up | µ ∼ 0.2 | This is when head-on at the start of the fill. |
| 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 = 0.05-0.1 | 0.05 in the first fill, 0.1 in the subsequent fills. |
| Peak pile-up | µ ∼ 0.22 | This is if head-on at the start of the fill. |
| 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 ∼ 0.11 | This is when head-on at the start of the fill. |
The Neon-Neon run will follow closely the Oxygen-Oxygen configuration but the emittance may be different and intensity per bunch will also be different. Some tests in the injectors have been done but this beam has never been into the SPS so the performance still has large uncertainties.
| General beam properties | ||
|---|---|---|
| Beam energy | 5.36 ZTeV | |
| Nucleon-nucleon CoM energy | 5.36 TeV | |
| Beam 1 | Neon ions | |
| Beam 2 | Neon ions | |
| Max number of bunches per beam | 52 (48 colliding) | Multi_52b_32_32_32_4bpi_13inj_800ns_bs1000ns_Oxygen |
| Minimum Bunch spacing | 1 µs | Injections widely spaced to aid ATLAS IBL veto. |
| Bunch intensity | ∼ 1.17 x 1010 charges per bunch | This beam is yet to be seen in the SPS. |
| Beam emittance | 2.1 µm | Large uncertainty on this. |
| (Assumed) Hadronic cross-section | 1.30 barns | We use the same as OO to simplify the configuration. |
| IP1 (ATLAS) | ||
| Peak pile-up | µ ∼ 0.044 | This is when head-on at the start of the fill. |
| IP5 (CMS) | ||
| Peak pile-up | µ ∼ 0.044 | This is when head-on at the start of the fill. |
| IP2 (ALICE) | ||
| Peak pile-up | µ ∼ 0.047 | This is when head-on at the start of the fill. |
| IP8 (LHCb) | ||
| Peak pile-up | µ ∼ 0.02 | This is when head-on at the start of the fill. |