The BRAN luminosity detectors for the LHC
| Autor: | Enrico Bravin, A. Ratti, Ryoichi Miyamoto, M. Placidi, W. C. Turner, H. S. Matis |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Accelerator Physics (physics.acc-ph)
Nuclear and High Energy Physics Physics - Instrumentation and Detectors Physics::Instrumentation and Detectors FOS: Physical sciences 01 natural sciences High Energy Physics - Experiment 030218 nuclear medicine & medical imaging law.invention Nuclear physics 03 medical and health sciences High Energy Physics - Experiment (hep-ex) 0302 clinical medicine law 0103 physical sciences Detectors and Experimental Techniques Collider Neutral particle physics.ins-det Instrumentation physics.acc-ph Physics Range (particle radiation) Large Hadron Collider Luminosity (scattering theory) hep-ex 010308 nuclear & particles physics Detector Instrumentation and Detectors (physics.ins-det) Accelerators and Storage Rings Ionization chamber Physics::Accelerator Physics Physics - Accelerator Physics Particle Physics - Experiment Beam (structure) |
| DOI: | 10.48550/arxiv.1612.01238 |
| Popis: | This paper describes the several phases which led, from the conceptual design, prototyping, construction and tests with beam, to the installation and operation of the BRAN (Beam RAte of Neutrals) relative luminosity monitors for the LHC. The detectors have been operating since 2009 to contribute, optimize and maintain the accelerator performance in the two high luminosity interaction regions (IR), the IR1 (ATLAS) and the IR5 (CMS). The devices are gas ionization chambers installed inside a neutral particle absorber 140 m away from the Interaction Points in IR1 and IR5 and monitor the energy deposited by electromagnetic showers produced by high-energy neutral particles from the collisions. The detectors have the capability to resolve the bunch-by-bunch luminosity at the 40 MHz bunch rate, as well as to survive the extreme level of radiation during the nominal LHC operation. The devices have operated since the early commissioning phase of the accelerator over a broad range of luminosities reaching 1.4*10^34 cm-2 s-1 with a peak pileup of 45 events per bunch crossing. Even though the nominal design luminosity of the LHC has been exceeded, the BRAN is operating well. After describing the multiple applications that the BRAN can be used to monitor the luminosity of the accelerator, we discuss the technical choices that led to its construction and the different tests performed prior to the installation in two IRs of the LHC. Performance simulations are presented together with operational results obtained during p-p operations, including runs at 40 MHz bunch rate, Pb-Pb operations and p-Pb operations. Comment: 22 pages, 32 Figures |
| Databáze: | OpenAIRE |
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