B. E. Karlsen-Baeck, T. Argyropoulos, A. Butterworth, R. Calaga, I. Karpov, H. Timko, M. Zampetakis
{"title":"腔体预调谐对注入大型强子对撞机的射频功率瞬态的影响","authors":"B. E. Karlsen-Baeck, T. Argyropoulos, A. Butterworth, R. Calaga, I. Karpov, H. Timko, M. Zampetakis","doi":"10.1088/1748-0221/19/04/t04005","DOIUrl":null,"url":null,"abstract":"\n At injection into the Large Hadron Collider (LHC), the radio\n frequency (RF) system is perturbed by beam-induced voltage resulting\n in strong RF power transients and the instant detuning of the\n cavities. The automatic tuning system, however, needs time for the\n mechanical compensation of the resonance frequency to take\n place. Acting back on the beam, the transients in RF power are\n expected to limit the maximum injected intensity by generating\n unacceptable beam loss. Reducing them is therefore essential to\n reach the target intensity during the High Luminosity (HL) LHC\n era. At LHC flat bottom, the cavities are operated using the\n half-detuning beam-loading compensation scheme. As implemented\n today, the tuner control algorithm starts acting only after the\n injection of the first longer bunch train which causes the bunches\n for this injection to experience the largest power spikes. This\n contribution presents an adapted detuning scheme for the RF cavities\n before injection. It was proposed as a path to decrease the\n transients, hence increasing the available intensity margin for the\n available RF power. The expected gain is evaluated in particle\n tracking simulations and measurements acquired during operation.","PeriodicalId":507814,"journal":{"name":"Journal of Instrumentation","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effects of cavity pre-detuning on RF power transients at injection into the LHC\",\"authors\":\"B. E. Karlsen-Baeck, T. Argyropoulos, A. Butterworth, R. Calaga, I. Karpov, H. Timko, M. Zampetakis\",\"doi\":\"10.1088/1748-0221/19/04/t04005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\n At injection into the Large Hadron Collider (LHC), the radio\\n frequency (RF) system is perturbed by beam-induced voltage resulting\\n in strong RF power transients and the instant detuning of the\\n cavities. The automatic tuning system, however, needs time for the\\n mechanical compensation of the resonance frequency to take\\n place. Acting back on the beam, the transients in RF power are\\n expected to limit the maximum injected intensity by generating\\n unacceptable beam loss. Reducing them is therefore essential to\\n reach the target intensity during the High Luminosity (HL) LHC\\n era. At LHC flat bottom, the cavities are operated using the\\n half-detuning beam-loading compensation scheme. As implemented\\n today, the tuner control algorithm starts acting only after the\\n injection of the first longer bunch train which causes the bunches\\n for this injection to experience the largest power spikes. This\\n contribution presents an adapted detuning scheme for the RF cavities\\n before injection. It was proposed as a path to decrease the\\n transients, hence increasing the available intensity margin for the\\n available RF power. The expected gain is evaluated in particle\\n tracking simulations and measurements acquired during operation.\",\"PeriodicalId\":507814,\"journal\":{\"name\":\"Journal of Instrumentation\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-04-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Instrumentation\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1088/1748-0221/19/04/t04005\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Instrumentation","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1088/1748-0221/19/04/t04005","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Effects of cavity pre-detuning on RF power transients at injection into the LHC
At injection into the Large Hadron Collider (LHC), the radio
frequency (RF) system is perturbed by beam-induced voltage resulting
in strong RF power transients and the instant detuning of the
cavities. The automatic tuning system, however, needs time for the
mechanical compensation of the resonance frequency to take
place. Acting back on the beam, the transients in RF power are
expected to limit the maximum injected intensity by generating
unacceptable beam loss. Reducing them is therefore essential to
reach the target intensity during the High Luminosity (HL) LHC
era. At LHC flat bottom, the cavities are operated using the
half-detuning beam-loading compensation scheme. As implemented
today, the tuner control algorithm starts acting only after the
injection of the first longer bunch train which causes the bunches
for this injection to experience the largest power spikes. This
contribution presents an adapted detuning scheme for the RF cavities
before injection. It was proposed as a path to decrease the
transients, hence increasing the available intensity margin for the
available RF power. The expected gain is evaluated in particle
tracking simulations and measurements acquired during operation.