Phase stability and RF level distribution Requirements Distribution type & MO location Cable requirements ( phase versus T° stability & diameter) Coupling value T° regulation solution (heater, water, ...) A PRDS 9m prototype is realized to test several T° regulation and insulation solution. The tests are in progress. 50 100 150 200 0 0.1 0.2 0.3 0.4 Lg 704.4 , ( ) Lg 352.2 , ( ) Lg 176.1 , ( ) 0.1 Lg Christophe Joly*, Sylvain Berthelot, Beng-Yun Ky,Thomas Lester, Wladimir Sarlin, Jean-François Yaniche , Institut de Physique Nucléaire (UMR 8608)- CNRS/ IN2P3-Université Paris-Sud, Orsay, France Holger Podlech Johann Wolfgang Goethe Universitaet (Institute of Applied Physics) Frankfurt am Main, Germany Dirk Vandeplassche Centre d'études et de recherche Nucléaire (SCK*CEN), Mol, Belgium LLRF for the RFQ prototype of the MYRRHA project LLRF17 Workshop / Barcelona, Spain /Oct 16-19, 2017 The goal of the European project called MYRTE (MYRRHA Research and Transmutation Endeavour), is to perform research to support the development of the MYRRHA facility (Accelerator Driven System) with a main topic for the “Accelerator R&D for ADS/MYRRHA” Work Package (WP2): the Injector demonstration. Within this framework, a Low Level Radio Frequency system for the Radio Frequency Quadrupole (RFQ) is developed by IPNO with an in-house standalone digital board including 2 FMC boards associated to a FPGA linked to a processor ARM by PCIe. A Phase References generation system has been also realized and tested with the expected performance. This poster presents the project and focuses to the hardware developments and to some results before the tests with the RFQ planned in May 2018. This work is supported by the European Atomic Energy Community’s (Euratom) H2020 Program me under grant agreement n°662186186 (MYRTE Project). Conceptual layout of the MYRRHA Facility Single SPOKE 352MHz Double SPOKE 352MHz Elliptical 704MHz RFQ + CH 176MHz Goals : Build a hybrid reactor demonstrator for transmuting radiotoxic waste, (ADS). Radio Isotopes production to medicine Fundamental research Parameters of the MYRRHA project Particles protons Energy [MeV] 600 Frequency [MHz] 176.1 - 352.2 -704.4 Duty Factor [%] 100 (cw) I [mA] 4 Beam power [MW] 2.4 MTBF [Hour] 250 Energy stability [%] ±1 Current stability [%] ±2 Reactor power th [MW] ≈60 keff ≈0.95 Fuel MOX Target Eutectic Pb-Bi RFQ LLRF requirements Amplitude stability [%] ±0.2 rms Phase stability [Degree] ±0.2 rms Frequency [MHz] 176.1 Bandwidth [kHz] > 84 RFQ Parameters RF Structure 4.Rod Frequency [MHz] 176.1 Beam current [mA] 5 Duty factor [%] 100 E out [MeV] 1.5 R p [kWm] 72 RF Power [kW] 113 Specific power [kW/m] 26.5 Voltage [kV] 44 Length [m] 4 Institut für Angewandte Physik LINAC AG RFQ assembly in progress at NTG facility LLRF Requirements ECR RFQ MEBT-1 CH-cavities MEBT-2 CH-cavities Injector in detail (new design) Due to beam dynamics studies of the global accelerator and the RFQ characteristics, the stabilities requirements will be better than ±0.3% rms and ±0.3° rms. In this respect, a budget has been defined for the complete LLRF system composed to the Master oscillator (MO), the Phase Reference Distribution System (PRDS) and the LLRF Feedback loop system. Then other parameters must be taken into account as accelerator length, temperature variation into the tunnel, etc. LLRF FB System Master Oscillator REF Distribution 0.2 - - 0.1 0.1 0.1 Distribution by subsystem PRDS MO LLRF FB loop system Frequency [MHz] Jitter rms [mDeg] Jitter rms [fs] 88.05 1.6 50 176.1 2.0 33 352.2 4.5 36 704.4 8.4 33 Results and [email protected] X2 X2 X4 X2 704.4 MHz 352.2 MHz 176.1 MHz 88.05 MHz PLL 88.05 MHz Splitter X2 Multipliers 10 MHz REF for Local oscillator generation Sampling clock 25kHz bandpass Filter X N 10MHz Oscillator Distribution amplifier The LLRF system for the RFQ is based on a in-house digital mother board called DALTON using a FPGA linked to a processor ARM by PCIe, with two FMC slots. For HW and SW details, see P-38 “EPICS and VHDL developments in the LLRF for MYRRHA Project's RFQ prototype” poster. The regulation loop principle is based on the processing of the RF cavity pick-up signal which is down-converted to an 10 MHz Intermediate Frequency (IF) signal. This IF signal is then sampled by an ADC (FMC104-4DSP) to be processed into the FPGA. The result is two I/Q control signals which are converted by 2 DACs ( and used to modulate the RF reference signal feeding the cavity, via a vector modulator. The MO provides the Phase reference at 176.1MHz and the 10MHz need to produce the Local oscillator (LO) signal, used by the down converter. The Master Oscillator is realized using parts with Phase Noise requirements very hard providing by ar Electronique (OCXO, PLL) and Wenzel Associates (multipliers). A narrow bandpass filter allows reducing the PLL noise as it is shown on the plot. Conclusion Fault tolerance Interlocks Bus Auxiliaries Control System PLC Master Oscillator LLRF Feedback Loop System PRDS Frequency Tuning System Fast Interlocks System Pf Pr Pt Coupler 10MHz Beam axe Vacuum , T°, cooling, Cooling, defaults SSPA RF authorization Personnel Safety System RF authorization Machine Protection System Gb-Eth (EPICS) IOC Timing EVG Timing EVR Optical link tuner RFQ P A Timing & Master Oscillator FPGA Digital board DAC ADC DAC I Q ADC • Digital signal processing • Set points • Frequency tuning • Interlocks management • Communication EPICS • Feed Forward DAC REF Clock ( ADCs & DACs) Timing ( Beam pulses, RF pulses,…) 10MHz RF REF RF RF-10MHz Frequency Tuning System Fault tolerance Interlocks Bus Others Data (Forward power, Reflected Power,…) RF switch Frequency Down converter Personal Protection Safety Diagnostics signals Gb-Eth (EPICS) Vector modulator RFQ Machine Protection System The LLRF prototype for the RFQ composed of the MO, PRDS and the FB loop will be tested in real condition in 2018 at Louvain-La-Neuve in Belgium where will be installed the injector until 6 MeV. The Master Oscillator prototype gives very good phase noise results with a jitter inferior to 50fs for all references. The PRDS needs more tests to conclude about the T° regulation. The FB loop hardware and software (VHDL and EPICS) are close to be operational and in parallel, we are studying a MTCA based version adapted to the MYRRHA reliability requirements. Thank you to the IAP, SCK*CEN and IPNO teams for their support. ECR LEBT RFQ CH β 0.375 Single Spoke β 0.705 Elliptical ECR LEBT RFQ CH β 0.49 Double Spoke 176 MHz 352 MHz 704 MHz SC section injectors 60 cavities 18 cavities 72 cavities Beam stop Spallation target & sub-critical core 600 MeV 32 m 11 m 91 m 35 m 120m 15 cavities Phase stability versus length for 0.1°C temperature variation using a LCF38-50J FN( phase vs T° stability coef <6 ppm/°C, velocity : 87%) 10 Tc (K type) per 3 m section positioned inside and outside for a profile of temperature. Insulated duct heater Cooling water Coupler T° sensors REF cables Contact : [email protected]