RF system & magnetic PU ELENA review meeting CERN, November 2015 M.E. Angoletta, S. Hancock, M. Haase, M. Jaussi, A. Jones, J. Molendijk, M. Paoluzzi, J. Sanchez-Quesada (BE/RF), F. Caspers, F. Pedersen (BE/RF honorary members)

Overview RF Workpackages Sub-WP1: HLRF Sub-WP2: LLRF Sub-WP3: Magnetic PU Sub-WP4: Head ampli + summing unit Sub-WP5: Longitudinal processing system Sub-WP9: Procurement of instrumentation & diag. ConclusionsOutline M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

RF workpackage overview RF workpackage includes (with budget):  Sub-WP1  Sub-WP1: Low-voltage broadband cavity and amplifier (HLRF)  Sub-WP2  Sub-WP2: LLRF hardware, firmware, DSPing, controls integration  Sub-WP3  Sub-WP3: Magnetic Longitudinal PU (LPU) – ring + extraction lines  Sub-WP4  Sub-WP4: Ultra-low-noise head amplifier, summing unit & cabling  Sub-WP5  Sub-WP5: Longitudinal Schottky processing system  Sub-WP9:  Sub-WP9: Procurement of lab/ring instrumentation & diagnostics  BI in charge of the system  Same digital signal processing as for magnetic LPU case [RF Sub-WP5] after signals rotation & sum. Collaboration with BI on longitudinal diagnostics from distributed electrostatic system, implemented on BI orbit system BI orbit system uses same h/w as LLRF  Interfaced with LLRF, as it receives clock + frev information from LLRF crate  Local clock generator during cold checkout RF Magnetic PU M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

RF workpackage layout Sub-WP1 Sub-WP2 Sub-WP3(ring) Sub-WP4 Sub-WP5 M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 1 HLRF M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 1 HLRF: overview  Located in ELENA’s section 5.  Finemet-based, broadband, untuned cavity.  Operating freq. range: 144 kHz → > 2 MHz  Voltage: 100 V, f< 500 kHz 500 V, f ≥ 500 kHz  Multi-harmonic voltage amplitude/phase loop by LLRF.  Gap-relay shortcircuits cavity when no voltage is applied.  HLRF control rack: AYE03 NB: HLRF voltage range agreed after many discussions on noise that could heat the beam M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 1 HLRF: status & budget  Installation planned for April  Oasis signals already foreseen and budgeted for.  Cost for whole sub-WP: 125 kCHF M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP2 LLRF M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP2 LLRF: overview  Location: RF01+RF02 in ELENA hall to minimize cable length from ring equipments (LPU).  Will interface with new Btrain distribution system (white rabbit)  Capabilities:  Cavity servoloop + multi-harmonic control of HLRF  Phase loop (from magnetic PU)  Radial loop (now only one TPU planned, discussions ongoing for more TPUs)  Synchro injection (reference generated in both cases by AD Highland module)  LLRF hosts LPU processing h/w and RF crate hosts Tomoscope hardware. M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting  Same CERN custom-made hardware as PSB DLLRF, ADC FMC optimised for low noise

Sub-WP2 LLRF: status & planning  H/w ready for installation in May  Standard tools will operate it:  Analogue signals available for observation also in ADCR  Btrain interfacing  Firmware & software, Oasis signals specifications (analogue + digital), detailed system specs: still to be started (lack of manpower)  “Non trivial” interfacing  Successful tests with RF-made white rabbit frame simulator.  Must validate with real fiber transmission → need help from Btrain people.  Number of TPU for radial loop  Since 2007 only 1 TPU planned. More TPUs might be desired (all ELENA PU in dispersive regions).  It affects system layout + h/w needed → decision must come by Dec 2015  knobs, function editors etc.  RF-specific application program (synoptic) done by RF group. M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP2 LLRF: budget  Cost for whole sub-WP: 100 kCHF Controls hardware, FMC production, installation M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 3 magnetic LPU: ring LPUs M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 3 magnetic LPU: overview  Complete re-design of AD version  Smaller dimensions  Different ferrite(s)  Bakeable  4 LPUs for ELENA, 3 ferrites  Ring: high-frequency (HF) + low-frequency (LF) in section 2. Combined BW = [0.003 – 30 MHz].  Extraction lines: 2 LF as single-pass beam transformers (only intensity meas needed.) C2010 (HF LPU) CN20 (LF LPU) M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 3 magnetic LPU: overview (cont’d)  LLRF: beam phase + synchronisation loops.  Longitudinal diagnostics processing (see Sub-WP5)  Tomoscope: bunch length, emittance  Oasis: analogue signal acquisition  TRIC system (BI): single-pass intensity measurement in extraction lines ring  Output: analogue signal. See Sub-WP4 for associated electronics.  Users:  NB: LPU development was not an easy task: succession plan for magnetic PU sub-WP and lack of documentation on AD-style magnetic PU. M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 3 magnetic LPU: status & planning  Ferrite already received: 10 rings C2010 (HF) and 20 rings CN20 (LF).  By 10 Dec expected 20 rings “New Ferrite” (LF).  Installation: expected to be completed by May 16 th for all LPUs (ring + extraction line).  No spare C2010 ferrites (HF) → careful when assembling!  Ordered different type of ferrite for LF LPU → to be measured when received (what if not acceptable?)  Early installation on extraction lines not urgent but preferred so as not have to break vacuum and re-bake afterwards (LPUs on extraction lines are part of the vacuum enclosure). Drawback: it takes manpower from ring-related tasks.  No contingency with respect to bakeout (starts on May 24 th and lasts for 6 weeks).  Delay now depends mainly on main workshop workload. M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 3 magnetic LPU: budget  Cost for whole sub-WP: 225 kCHF  NB: 120 kCHF for main workshop job currently allocated to 2015 (but it could move to 2016). M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 4 head ampli, summing unit M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 4 head ampli, summing unit: overview  Head amplifier (attached to magnetic LPU): re-design of AD version  Lower low-frequency cut-off needed (20 kHz in AD, now it must be ~ 3 kHz)  Will be removed during bakeout  Summing unit (ELENA hall): new design  Sums ring LF + HF to provide single, wide-band analogue signal.  Distance between LPU gaps introduces phase frequency bigger than for AD → the design of this unit is more complex!  We can start with LF signals only and add the summing unit at a later stage.  Several analogue signals available also in AD CR for observation  Ex: summed and LF/HF signals for spectrum analyse “a la AD”. M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 4 head ampli…: status, planning & budget  Simulations done for Schottky noise, noise levels referred to the gap etc.  Head amplifier: ready for installation before end May.  Cost for whole sub-WP: 64 kCHF M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 5 magnetic LPU processing M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 5 magnetic LPU processing: overview  Output: longitudinal beam parameters for ring signals  Bunched beam: intensity  Debunched beam:  intensity (from Schottky scans)  Δp/p (main ecooling diagnostics)   Averaged beam spectra  Interfaced to LLRF as piggy-back (no influence on LLRF operation)  ADC FMC optimised for low-noise  Hosted in same crate as LLRF. Noise floor below 10 nV / √ Hz. To be used also for BI Orbit system AD Schottky Gui (picture from 2002) M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 5 magnetic LPU processing: status & planning  Hardware: ready for installation before mid-May,  Detailed system specifications: still to be started (lack of manpower).  New firmware development  Will be available asap but possibly not as early as July (it depends on manpower available)  New firmware + DSP code to be developed  A new clocking scheme (fixed clock instead of sweeping clock) will be required for final system deployment (bunched beam measurements).  Application program done by OP once FESA classes are ready (May 2016). M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 5 magnetic LPU processing: budget  Cost for whole sub-WP: 30 kCHF  Cost limited as system is piggy-back on LLRF (not standalone or separate system). M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Sub-WP 9 procurement of instrumentation & diagnostics  Instrumentation & diagnostics for lab/ring  Includes Tomoscope and Oasis hardware  Cost for whole sub-WP: 140 kCHF VNA + Spectrum analyser + probes (received & operational) M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Conclusions  RF workpackage well advanced for ELENA project.  ELENA project will profit from the successful experience with new DLLRF in PSB (and soon also in LEIR).  Good synergy with BI (win-win situation)  Lack of manpower! Same people working on concurrent projects (LEIR LLRF upgrade, PSB upgrade, machine maintenance & support…)  Critical path: magnetic LPU assembly and installation.  ELENA beam commissioning will be tough very interesting…  It depends now on the main workshop workload.  LPU development was not an easy task: succession plan for magnetic PU sub-WP and lack of documentation on AD-style magnetic PU.  … and the fact that it starts in summer does not help (see LEIR experience).  Expenses consistent with previous estimates. Total: 680 kCHF  No commissioning expenses in M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Additional slides M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Processing system: debunched beam  Spectral analysis of Schottky signals to obtain longitudinal beam parameters.  Intrinsically noisy: noise statistical properties (incoherent signal) observed.  In AD: sensitive to instabilities, filamentation/ external noise… → Schottky power “explodes”.  Noise offset calibration needed  S/N improved by FFT averaging.  AD typical meas. rep. period: ~ 1 s.  Observation BW changed during cooling. Longitudinal Schottky integrated power. M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Processing system: bunched beam Longitudinal bunched processing: RF harmonics Fourier analysis.  DAQ clocked at h · f REV,  AD method: Fourier analysis of RF harmonics assuming a certain bunch shape.  Drawback: dependency on bunch shape. New bunched-beam digital signal processing.  New h/w + firmware allows integrating over bunch shape and subtracting the baseline. M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting

Longitudinal diagnostics calibration Bunched beam vs. LF LPU in transfer line Bunched beam intensity vs. debunched Schottky meas.  Extraction LPUs can be calibrated in absolute way via C discharge.  Bunched measurement before extraction compared to measurement in extraction line (single-pass beam transformer)  Assumptions: 100% extraction efficiency.  Same magnetic LPU and control chain  Debunched intensity = f(GAIN 2 ), bunched = f(GAIN). M. E. Angoletta, 12 November 2015 “RF system & Magnetic PU” ELENA review meeting