Recent LLRF Developments at CERN and New Projects Wolfgang Hofle on behalf of BE-RF-FB and BE-RF-CS Section LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk

Overview CERN LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk Advanced Proton Driven Plasma Wakefield Acceleration Experiment LHC 2015: 6.5 TeV reached, half nominal Luminosity; upgrades for HighLumi: crab cavities  challenging LLRF SPS: major LLRF and RF upgrades under way: 4  6 MHz, 800 MHz system upgrade Roll-out of DLLRF: PSB, LEIR, AD, ELENA; new Finemet system for PSB PS: Coupled Bunch feedback with Finemet cavities HIE-Isolde, 100 MHz SRF with DLLRF LINAC4: staged commissioning: Connection to PSB: 2018/2019

Last two years: Restart after Long Shutdown 1 (LS1) LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk Physics Beam commissioning Shutdown Powering tests FMAMJJASONDJFJFMAMJJASOND MA beam to beam available for works LHC Run 2: 2015 (6.5 TeV), 2016, 2017, flat out Preparing for Long shutdown 2 (LS2) LHC Injector Upgrades: LLRF for SPS, new RF system for PSB (Finemet), LINAC4 connection, crab cavity tests in SPS

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk LHC LLRF: controlled noise injection  Studies on the use of colored noise and RF modulation to shape the longitudinal bunch profile (needed for stability and longitudinal blow-up)  LHC RF phase noise generation, phase loop, and bunch length feedback implemented in new numerical code “BLonD” to include the LLRF  Implementation of LLRF control and blow-up in software H. Timko, E. Shaposhnikova, P. Baudrenghien Initial Final Talk by A. Butterworth on CERN LLRF Software Architecture

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk Linac4 LLRF J. Noirjean, J. Galindo, D. Stellfeld, G. Hagmann, P. Baudrenghien, M. Ojeda May 2014 Cavity Filling Ramp (50  s) Feedback On Zoom  Installed on RFQ, Bunching cavities 2-3, DTL1  Observed ripple: 0.06% voltage, 0.05 deg, without beam  Transient beam loading: 1% voltage with 8 mA beam  Pulse to pulse reproducibility: deg LHC LLRF type VME platform See Talk by J. Galindo

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk 6 New PSB Digital LLRF system Four operational Digital LLRF systems (Ring 1 to 4) + development ring (ring 0) which operates Ring 4 beams in PPM with Ring 4 DLLRF. Big RF group investment (manpower) for Meyrin machines. PSB operational LLRF after LS1 Mandatory for PSB Finemet R&D campaign ( ). Will be deployed in LEIR in 2015 and in ELENA (Anti-proton deceleration) in The hardware The results Talks by M.E. Angoletta and J. Molendijk

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk CERN-MedAustron collaboration (HLRF + LLRF) Successfully delivered & contributed to commission Digital LLRF (PSB-style) + HLRF (Finemet-based ) systems for MA synchrotron. MA milestones so far: LLRF team to keep supporting MA Ring RF system when possible.  26 May ‘14: first capture  20 Oct ‘14: first extraction to MeV  6 Nov ‘14: 10E8 protons extracted to MeV MedAustron synchrotron Irradiation Room 3 (IR3) MedAustron complex M. E. Angoletta, M. Jaussi, J. Molendijk, M. Paoluzzi, J. Simonin, J. Sanchez Quesada

HIE-Isolde DLLRF LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk Front end computer 6x LLRF controller LHC type VME Platform radioative ions post acceleration (low intensity) only 16 meters long, final stage: 32 superconducting cavities (100 MHz) challenge to control the cavity, only few Hz bandwidth LLRF entirely digital, direct RF sampling, direct RF generation 32 solid state RF amplifiers, 700 W each commissioning started in summer 2015 (1 RF module with 5 cavities) first Beam successfully accelerated last month D. Valuch, M. Elias, M. Mician Poster (M. Mician) and Talk (D. Valuch)

PS Coupled Bunch Feedback LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk -3 dB 66 Splitter + amp. Coupled- bunch feedback Comb. + att. Beam- loading reduction Wall current monitor f clk = 256 f rev  Single LLRF driving all six cells Cavity return sum  Two feedbacks: 1. Beam  Finemet cavity, 2. Cavity return  cavity  no detrimental effect on beam stability observed so far See Talk by H. Damerau

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk  One-Turn delay feedback added on TWC800MHz Cavity 1 for compensation of transient beam loading LIU SPS: LLRF for 800 MHz TWC (1) G. Hagmann, P. Baudrenghien, D. Valuch, S.J. Calvo  Cavity Vector sum (37 cells)

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk LIU SPS: LLRF for 800 MHz TWC (2) G. Hagmann, P. Baudrenghien, T. Bohl, M. Ojeda, A. Rey, F. Killing, J. Noirjean  Amplitude and phase of measured cavity voltage (800MHz)  Very effective compensation of the transient beam loading  To be deployed on 200 MHz RF system as well  RF (800MHz) demod to IF (25MHz)  ADC’s & Digital IQ (BW=12MHz)  FPGA:100MSPS signal processing  DAC’s & SSB Modulator to RF  ≤3.2Gbits/s links (SFP) Nov. 26 th, 2014 Feedback Gain=1 Feedback Gain=25 See Talks by G. Hagmann and C. Rivetta

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk SPS – Damper (transverse feedback) 12 G. Kotzian, T. Levens, D. Valuch A. Rey, Y. Le Borgne 4x new Board 120 MHz clocked complete new LLRF commisioned in 2014

Data recording: Observation Box LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk Linux kernel Driver Stack Transmitter SPEC Fiber Transmitter SPEC Transmitter SPEC TransmitterSPEC PCIe (DMA) FESA 3 RDA 3CMW ObsBox class Java RDA 3 OP application Ethernet Computer in TN LHC / SPS /.. Observation Box GPGPU RAM syscalls & sysfs CUDA/OpenCL VME modules with integrated Transmitters 4 x 1 / 2.5 Gb/s Objective: Overcome limitation of VME for data transfer to fully explore diagnostic potential of the digital LLRF systems SuperMicro’s SuperServer 6028U-TR4+ Simple PCIe FMC carrier (SPEC) RF specific firm ware: T. Levens A. Butterworth, M. Ojeda et al. ICALEPCS’15, WEPGF062

LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk LHC future upgrades: Crab Cavities  Transverse emittance growth caused by CC RF noise can reduce the integrated luminosity much  The dominant noise comes from the LLRF demodulator that must be improved: target= kHz offset.  Conceptual design of feedbacks is advancing  Test with a prototype cavity foreseen in the SPS in coming years For all betatron bands, the demodulator noise dominates the TX noise (filtered by cavity). 100 kHz regulation band T. Mastoridis, P. Baudrenghien

AWAKE Experimental Program LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk  Proton driven Plasma Wakefield experiment at CERN  Phase 1: Understand the physics of self modulation instability processes in plasma.  Phase 2: Probe the accelerating wakefields with externally injected electrons. 15 Laser dump e-e- SPS protons 10m SMI Acceleration Proton beam dump RF gun Laser p Proton diagnostics BTV,OTR, CTR e - spectrometer Plasma cell  Rb vapour source Proton beam  drives the plasma wakefield + undergoes self-modulation instability.  LHC-type proton beam, 400 GeV/c, 3E11 protons/bunch,  = 400 ps long Laser beam:  ionizes the plasma + seeds the self-modulation instability of the proton beam.  4.5 TW laser, 100 fs Diagnostics  BTVs, OTR, CTR Electron source and beam  Witness beam to ‘surf’ on the wakefield and get accelerated  16 MeV/c, 1.2 E9 electrons/ bunch,  = 4ps long Electron spectrometer system LLRF: Synchronisation of LASER with proton beam in SPS and electron beam Fast timing See Talk by J. Molendijk (fiber link drift compensation)

Summary  CERN Focus is on Injector Upgrades during the coming years: many LLRF challenges  New Projects: AWAKE, HIE-Isolde, ELENA  Make or buy ?  make  Platform ?  VME  Solution for data recording (ObsBox) LLRF'15 Shanghai, China - W.Hofle CERN Lab Talk