| Internal Note | |
| Report number | CERN-ACC-NOTE-2020-0056 |
| Title | MD2490 – Measurement of the TMCI threshold at flat-top in the LHC |
| Author(s) | Albert, Markus (CERN) ; Amorim, David (Universite Grenoble-Alpes (FR)) ; Antipov, Sergey ; Biancacci, Nicolo (CERN) ; Buffat, Xavier (CERN) ; Carver, Lee Robert (University of Liverpool (GB)) ; Fuchsberger, Kajetan ; Mereghetti, Alessio ; Metral, Elias (CERN) ; Mounet, Nicolas (CERN) ; Salvant, Benoit (CERN) ; Valuch, Daniel (CERN) |
| Corporate author(s) | CERN. Geneva. ATS Department |
| Publication | 2020 |
| Imprint | 28 Sep 2020 |
| Subject category | Accelerators and Storage Rings |
| Accelerator/Facility, Experiment | CERN LHC |
| Keywords | LHC ; Impedance ; Instability ; TMCI |
| Abstract | This report summarizes the results of MD2490 on the measurement of the intensity threshold of the Transverse Mode Coupling Instability (TMCI) in the LHC at flat top. The measurement took place during MD block 3 of 2017, on the night between 15th and 16th September. The betatron tune of bunches with different intensities was measured via ADT excitation and for different collimator settings, thus changing the machine impedance. The tune shift versus intensity measurement allowed to extrapolate the intensity threshold of the TMCI. Relaxing the collimator settings to mimic the HL-LHC impedance reduction also showed the beneficial effect of the collimator upgrade planned for HL-LHC. |
| Submitted by | [email protected] |
Record created 2020-10-27, last modified 2020-11-19
