Run 3 Results
Results from LHC Run 3 commissioning
Global aperture measurement at 30cm
29 June 2022: Collimator Scans and BBA
Link to LHC Logbook
The measurement was carried out with a \beta* of 30cm without separation bump. The crossing angles were -160urad in ATLAS and +160urad in CMS.
Global aperture measurements at injection
01 June 2022: Collimator Scans and BBA
Link to LHC Logbook
Fill number: 7686
The measurement was carried out with crossing and separation bumps, the reference orbit and optics were established with a nominal bunch which was then dumped and six pilot bunches were injected
27 April 2022: BBA Measurement
The measurement was carried out with flat machine at injection energy (450GeV). One pilot bunch (some 10^9 protons) was used for the measurement in each plane for both beams. As a first step the primary collimators were aligned (also angular alignment). Then all collimators were sent to parking and TCSP6 and TCDQ were driven out even further. After the excitation with the ADT, the primary collimators were aligned and the aperture is inferred from the gap when the beam is touched.
| Plane | Aperture (sigma) | Bottleneck location |
|---|---|---|
| B1H | >12.8 | TCDSA |
| B1V | 12.0-12.5 | n/a |
| B2H | >12.4 | TCDQ |
| B2V | >11.7 | Q4R6 |
Link to LHC Logbook
Offline analysis data [All, B1H, B1V, B2H, B2V]
24 April 2022: Collimator Scan Measurement
The measurement was carried out with flat machine at injection energy (450GeV). One pilot bunch (some 10^9 protons) was used for the measurement in each plane for both beams. We used the collimator scan method with the results listed in the table below.
| Plane | Aperture (sigma) | Bottleneck location |
|---|---|---|
| B1H | >13.0 | IP6 warm elements |
| B1V | 12.5-13.0 | MQY.4L6.B1 |
| B2H | >13.0 | IP6 warm elements |
| B2V | >13.0 | Q4R6 |
Link to LHC Logbook
Most recent presentations
P. Hermes et. al, Preliminary results from aperture measurements at injection in the Run 3 commissioning, Presentation at the special joint LNO-NDC Meeting, 27 April 2022.
P. Hermes et. al, Aperture Measurements in the LHC Run 3 Beam Test, Presentation at the 18th NDC Section Meeting, October 2021.