The new LEIR LLRF New LEIR LLRF features

The new LEIR LLRF New LEIR LLRF features HLRF Studies LLRF for MDs & operation Maria Elena Angoletta, A. Findlay, M. Jaussi, J. Molendijk, J. Sanchez-Quesada and S. Albright, S. Hancock and M. Haase, M. Paoluzzi MD Days, CERN, 24 March 2017

Outline 1. Overview & features (2016) 2. 2017 operation: Xe run 3. Plans for 2017 4. Conclusions & outlook

1. Overview & features (2016) v New, PSB-style LLRF successfully deployed in LEIR by July 2016 q 2 harmonics/Finemet cavity, h=1+2 or h=2+4 q Implements parallel operation of 2 Finemet cavities v Reasons for replacing previous LLRF: q Technical: s/w + h/w obsolescence q Functional: parallel operation of the two LEIR cavities required for Pb 2016 run (MDs, possible future operational mode). Could not be implemented in previous LLRF system for lack of processing power. v Acceptance limitation ~7 Me. V on flat bottom [Oct 2016, S. Albright]. q 2 -cavity operation not required anymore as operational mode. It might still be useful for MDs. → Simon’s talk for main beam results obtained. M. E. Angoletta “New LEIR LLRF features for MDs & operation” MD Days 24/03/2017 1

2. 2017 operation: Xe run v No new LLRF features required specifically for Xe operation: q general system setup with new ions species. q simple cycle, h=1 (EARLY-style), low intensity. . . q h/w + s/w cleanup planned to fully remove old LLRF → Little manpower originally planned for LEIR in 2017 run BUT v New features required for: q Operation of new LEIR orbit system (BE/BI) q MDs with Xe in 2017 to prepare for Pb operation. Aim: further optimization of RF capture process to gain intensity margin. M. E. Angoletta “New LEIR LLRF features for MDs & operation” MD Days 24/03/2017 2

3. Plans for 2017: overview v Many discussions with OP & ABP on new features. v Several potential requests (brainstorming ideas): q operation at h=3+6 q operation with additional harmonics (ex: h=1+2+3, as for PSB Finemet) q hollow bunches (as for PSB) q feedback on injection frequency offset function (LLRF) from Schottky measurement @end of accumulation plateau… Limitation: manpower-related, not technical (the LLRF could do it). Priority given to PSB → yesterday’s talk by MEA on PSB LLRF M. E. Angoletta “New LEIR LLRF features for MDs & operation” MD Days 24/03/2017 3

3. Plans for 2017: what we can do v Interfacing with new LEIR orbit system (BE/BI) Modify LLRF to provide frev value in real time via optical fiber q LEIR orbit: same h/w & mostly same firmware as LEIR new LLRF q Same ORBIT LLRF interface deployed in ELENA q MRP available to LLRF from new orbit system via fiber. Likely too slow to be of use for the radial loop (signals integration constraints from turnby-turn measurement needs) q v Setup LLRF operation @h=3+6 0 V q h=6 cavity voltage available only 500 V until mid-ramp 4 k. V q LLRF + Tomoscope s/w to be upgraded to h=3+6 operation M. E. Angoletta “New LEIR LLRF features for MDs & operation” MD Days 24/03/2017 4

4. Conclusions & outlook v v LEIR LLRF fully operational q Higher performance/capabilities than with previous LLRF q Very high reliability BUT New features (already!) required For studies / future beams (not Xe but Pb-related) q To interface with new systems q v Limited manpower available in 2017 for LEIR. q Only a selection of additional capabilities in view of Pb run 2018 can be developed and validated with beam in 2017. M. E. Angoletta “New LEIR LLRF features for MDs & operation” MD Days 24/03/2017 5