First measurements of beam backgrounds at SuperKEKB
| Autor: | Lewis, P. M., Jaegle, I., Budano, A., Cautero, G., Cecchi, C., Chen, Y.-T., Chu, K.-N., Cinabro, D., Cristaudo, P., de Jong, S., de Sangro, R., Finocchiaro, G., Nakayama, H., Flanagan, J., Funakoshi, Y., Gabriel, M., Giordano, R., Giuressi, D., Hedges, M. T., Honkanen, N., Ikeda, H., Ishibashi, T., Kaji, H., Aloisio, A., Kanazawa, K., Kiesling, C., Koirala, S., Križan, P., La Licata, C., Lanceri, L., Liau, J.-J., Lin, F.-H., Lin, J.-C., Liptak, Z., Ameli, F., Longo, S., Manoni, E., Marinas, C., Miyabayashi, K., Mulyani, E., Morita, A., Nakao, M., Nayak, M., Ohnishi, Y., Passeri, A., Barrett, M., Poffenberger, P., Ritzert, M., Roney, J. M., Rossi, A., Röder, T., Seddon, R. M., Seong, I. S., Shiu, J.-G., Simon, F., Soloviev, Y., Beaulieu, A., Suetsugu, Y., Szalay, M., Terui, S., Tortone, G., Vahsen, S. E., van der Kolk, N., Vitale, L., Wang, M.-Z., Windel, H., Yokoyama, S., Bosisio, L., Belle II Collaboration, Branchini, P., Browder, T. E. |
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| Přispěvatelé: | Lewis, P. M., Jaegle, I., Nakayama, H., Aloisio, A., Ameli, F., Barrett, M., Beaulieu, A., Bosisio, L., Branchini, P., Browder, T. E., Budano, A., Cautero, G., Cecchi, C., Chen, Y. -T., Chu, K. -N., Cinabro, D., Cristaudo, P., de Jong, S., de Sangro, R., Finocchiaro, G., Flanagan, J., Funakoshi, Y., Gabriel, M., Giordano, R., Giuressi, D., Hedges, M. T., Honkanen, N., Ikeda, H., Ishibashi, T., Kaji, H., Kanazawa, K., Kiesling, C., Koirala, S., Križan, P., La Licata, C., Lanceri, L., Liau, J. -J., Lin, F. -H., Lin, J. -C., Liptak, Z., Longo, S., Manoni, E., Marinas, C., Miyabayashi, K., Mulyani, E., Morita, A., Nakao, M., Nayak, M., Ohnishi, Y., Passeri, A., Poffenberger, P., Ritzert, M., Roney, J. M., Rossi, A., Röder, T., Seddon, R. M., Seong, I. S., Shiu, J. -G., Simon, F., Soloviev, Y., Suetsugu, Y., Szalay, M., Terui, S., Tortone, G., Vahsen, S. E., van der Kolk, N., Vitale, L., Wang, M. -Z., Windel, H., Yokoyama, S. |
| Rok vydání: | 2019 |
| Předmět: |
Accelerator Physics (physics.acc-ph)
Nuclear and High Energy Physics Physics - Instrumentation and Detectors FOS: Physical sciences Synchrotron radiation Accelerator BELLE Electron 01 natural sciences 7. Clean energy Beam–gas law.invention High Energy Physics - Experiment Beam background Nuclear physics High Energy Physics - Experiment (hep-ex) Beam–ga KEK-B law 0103 physical sciences Electron–positron collider ddc:530 Neutron Detectors and Experimental Techniques angular distribution [n] numerical calculations 010306 general physics Collider Touschek Instrumentation Nuclear and High Energy Physic Physics Luminosity (scattering theory) synchrotron radiation 010308 nuclear & particles physics energy spectrum [n] Detector Instrumentation and Detectors (physics.ins-det) Neutron temperature induced [background] Physics::Accelerator Physics Physics - Accelerator Physics injection [beam] Infrastructure for advanced calorimeters [14] Beam (structure) |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Nuclear instruments & methods in physics research / A A914, 69-144 (2019). doi:10.1016/j.nima.2018.05.071 Nucl. Instrum. Methods Phys. Res., Sect. A, () pp. |
| ISSN: | 0168-9002 |
| DOI: | 10.1016/j.nima.2018.05.071 |
| Popis: | The high design luminosity of the SuperKEKB electron-positron collider is expected to result in challenging levels of beam-induced backgrounds in the interaction region. Properly simulating and mitigating these backgrounds is critical to the success of the Belle~II experiment. We report on measurements performed with a suite of dedicated beam background detectors, collectively known as BEAST II, during the so-called Phase 1 commissioning run of SuperKEKB in 2016, which involved operation of both the high energy ring (HER) of 7 GeV electrons as well as the low energy ring (LER) of 4 GeV positrons. We describe the BEAST II detector systems, the simulation of beam backgrounds, and the measurements performed. The measurements include standard ones of dose rates versus accelerator conditions, and more novel investigations, such as bunch-by-bunch measurements of injection backgrounds and measurements sensitive to the energy spectrum and angular distribution of fast neutrons. We observe beam-gas, Touschek, beam-dust, and injection backgrounds. We do not observe significant synchrotron radiation, as expected. Measured LER beam-gas backgrounds and Touschek backgrounds in both rings are slightly elevated, on average three times larger than the levels predicted by simulation. HER beam-gas backgrounds are on on average two orders of magnitude larger than predicted. Systematic uncertainties and channel-to-channel variations are large, so that these excesses constitute only 1-2 sigma level effects. Neutron background rates are higher than predicted and should be studied further. We will measure the remaining beam background processes, due to colliding beams, in the imminent commissioning Phase 2. These backgrounds are expected to be the most critical for Belle II, to the point of necessitating replacement of detector components during the Phase 3 (full-luminosity) operation of SuperKEB. 101 pages, 127 figures |
| Databáze: | OpenAIRE |
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