DLLRF: existing & possible applications M. E. Angoletta, M. Jaussi, J. Molendijk, J. Sanchez-Quesada CERN, BE/RF Finemet ® Review, September 2015

1.PSB-style LLRF: not only LLRF 2.Medical applications and experience 3.KT transfer project & simplified LLRF 4.ConclusionsOutline

PSB-style DLLRF: not only LLRF applications!  Used for ( → later on this talk)  Evolution of LEIR DLLRF (1 st generation), deployed in  H/w family aimed at LLRF applications for Meyrin synchrotrons  Project started in  Includes LHC experience.  PSB-style DLLRF is 2 nd generation DLLRF system. M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/  Modular & flexible system : initially aimed at LLRF only, it has been adopted by BI for diagnostics applications. Ex: AD orbit, to be deployed in January 2016.

RF: ELENA LLRF + long. diag. system (baseline) M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 2

Longitudinal bunched processing  Intensity from Fourier analysis of RF harmonics (AD-style method). Bunch-shape dependence. New bunched-beam digital signal processing.  New method will integrate over bunch shape & subtract the baseline. RF: ELENA longitudinal diagnostics processing Bunched beam Bunched beam: intensity Debunched beam Debunched beam: intensity, dp/p and from Schottky signals analysis Debunched beam processing  Windowing & FFT averaging. M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 3

BI: ELENA orbit + long. diag. system (study) Beam orbit and distributed electrostatic PU system for longitudinal parameters measurement.  Innovative idea: add Σ signal from orbit transverse PUs to obtain a wide-BW distributed electrostatic PU.  Digital acquisition + processing with LLRF h/w.  Risk of head ampli saturation + very innovative processing: not baseline system for ELENA (… yet, but it could become such in the future). M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 4

4. H /w family: roadmap to other machines WhenWhatGroup 2015 LEIR DLLRF upgradeRF Discussions about possible PS LLRF upgrade.RF 2016 AD orbit systemBI ELENA LLRF + long. diagnostics from magnetic PUs (baseline)RF ELENA orbit systemBI ELENA long. diagnostics from distributed TPU (study)BI LEIR Schottky systemBI 2017 (?)LEIR orbit (if approved)BI >= 2017AD LLRF + long. diagnostics (when manpower allows)RF Isolde LLRF (it might not take place)RF >= LS2PSB operation with final HLRF system (Finemet ® or ferrite)RF M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 5

1.PSB-style LLRF: not only LLRF 2.Medical applications and experience 3.KT transfer project & simplified LLRF 4.ConclusionsOutline

DLLRF for medical applications: experience in RF group   : ME Angoletta contributed to the specification, design & commissioning of CNAO’s DLLRF as CERN expert.  CNAO HLRF: ferrite cavity.  CNAO LLRF: based on LEIR DLLRF & implemented by Grenoble team.   : LLRF development team contributed to the specification, design & commissioning of MedAustron (MA) DLLRF.  Same h/w + FPGA code as PSB DLLRF. Modified DSP code.  Boards designed by CERN for MA needs (Btrain + tune kicker interfacing).  LLRF team went to MA several times in 2014 for system commissioning  Remote commissioning sessions on MA DLLRF carried out from CERN. M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 6

CERN-MedAustron collaboration for LLRF  MA milestones so far:  26 May ‘14: first capture  20 Oct ‘14: first extraction to MeV  6 Nov ‘14: 10E8 protons extracted to MeV  4 August 2015: phase jump extraction scheme successfully validated MedAustron synchrotron Irradiation Room 3 (IR3) MedAustron complex M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 7

What a medical synchrotron (carbon and ions) needs  Beam loops & operation: similar to PSB/LEIR capture & acceleration.  Extraction: different schemes (long-duration homogeneous spill)  Medical synchrotron is typically before medical validation point. Less constraints on operation/upgrades than for beam delivery systems.  NB: need to generate/validate thousands of cycles. Substantial specification work on LLRF parameters done by MA + CERN LLRF experts.  NB: medical synchrotrons often include also non-clinical research facilities, possibly more RF gymnastic required there.  Phase, radial, frequency program. Function references: radial steering etc  Timings: soft, two hard references (C0 & extraction)  Typically PPM  Low number of harmonics to be servoed for Finemet ® HLRF (just h = 1 in MA)  Energy and f REV similar to PSB/LEIR range M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 8

Our approach & experience with MA  Functionality sharing  Functionality sharing: FPGA vs. DSP  FPGA: comms, function generation, housekeeping…  DSP: beam & cavity loops  Convenient for low-manpower machines, as DSP code can be easily modified.  Our expectations  Our expectations for MA operation/maintenance  H/w: full diagnostics available. In case of problems MA will rely on spares. CERN will keep supporting same h/w (extended in-houce usage).  FPGA code: does not change once finalised and debugged.  DSP code (C language): to be customised by MA for future system evolution.  MA experience  MA experience: planned milestones always reached but…  Now only one person for RF operation and setup. (!)  High people turnover (mostly controls integration specialists) → lost transferred knowledge.  Full system knowledge and “ownership” not yet acquired by MA. NB: Not yet fully available system documentation owing to CERN priorities. M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/2015 9

1.PSB-style LLRF: not only LLRF 2.Medical applications and experience 3.KT transfer project & simplified LLRF 4.ConclusionsOutline

Knowledge transfer project funding  In 2016 we will apply for a CERN Knowledge Transfer (KT) project funding to develop a (simplified) DLLRF for medical accelerators.  Useful application of CERN-specific knowledge. “CERN is doing its bit to make the return to society through medicine even better” [CERN DG on bio-LEIR, could very well be applied to this project, too].  CERN → KT: w e’ll develop in any case several features (ex: multi harmonic HLO sources) that will be included in the simplified DLLRF.  KT → CERN: the KT-funded manpower will contribute to develop concepts useful for our 3 rd generation LLRF (ex: FPGA with embedded processor: Xilinx ZYNQ SoC FPGA family well suited to replace Main FPGA + DSP).  This project fits well within the KT framework  Funding required for development: manpower (fellow?) + material + prototyping.  DLLRF companion of Finemet ® HLRF (but it can work with other HLRF systems). M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/

Simplified LLRF?  Remove from FPGA+DSP code features/setup parameters not strictly required (but deployed in PSB system) powerfulintelligent complex There is room for simplification but LLRF is a very powerful, intelligent & complex system per se, highly integrated in the synchrotron. Simplification possible only to a certain extent.  LLRF is not a standalone box: it must interact with many other systems in the accelerator. Interfaces will be available (but systems might require adaptation boards).  FESA 3 (master VME code) is designed to be more easily decoupled from the CERN facility (already exported to GSI).  LLRF loops depend also on beam and synchrotron specs./performance. Difficult to provide a turn-key commissioning.  some PSB-style parameters left in MA proved to be very useful!! Ex: fixed frequency for PSB ≠0. M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/

Conclusions  A powerful DLLRF system has been and successfully deployed on 4 rings PSB + MedAustron.  DLLRF h/w will be also used for diagnostics by RF & BI groups.  Experience exists in RF group on LLRF for medical machines (CNAO, MedAustron) + for Finemet operation: LEIR (since 2005), MedAustron + PSB Ring 4 (since 2014).  KT project funding request to be submitted in 2016 for manpower + material + prototyping to develop a simplified LLRF for medical applications. M. E. Angoletta “DLLRF: existing & possible applications” Finemet Review, 14/09/  DLLRF companion of Finemet ® HLRF.  DLLRF team would profit to validate concepts for 3 rd generation DLLRF  DLLRF team very enthusiastic of this “do good” project.