Status of the ESS Accelerator Workpackage

Transcription

1 Status of the ESS Accelerator Workpackage Peter McIntosh STFC Daresbury Laboratory UK ESS Interactions and Opportunities Rutherford Appleton Laboratory 3 Dec 2014

2 The ESS Linac The European Spallation Source (ESS) will house the most powerful proton linac ever built: Average beam power of 5 MW. Peak beam power of 125 MW Acceleration to 2 GeV Peak proton beam current of 62.5 ma Pulse length of 2.86 ms at a rate of 14 Hz (4% duty factor) 97% of the acceleration is provided by superconducting cavities. The linac will require over 150 individual high power RF sources: With 80% of the RF power sources requiring over 1.1 MW of peak RF power. Expect to cost over 200 M on the RF system alone! 2

3 Top-Level ESS Project Schedule Start Of Construction Construction End Of Construction 3 ESS Program Conventional Facilities Accelerator Target Neutron Scattering Systems Integrated Control Systems Design Design Construction Building Commissioning Design & Prototyping Procurement Design Procurement Concept Devlopment Design Design Development Ground Break Installing Commissioning Licensing Preliminary Design Acccelerator Bldngs Detailed Design Accelerator Bldngs Construction Installation Commissioning Installation Commissioning Commissioning First installations (of Machine Systems) Earth Works G01 Linac Tunnel G02 Klystron Bldng Cryo Kompressor Bldng Commissioning First Neutrons Machine 2.0 GeV Concluding Initial Operation Accelerator, Target, Aux, Office, Lab & Instr Bldngs* Medium Beta Fabrication Spoke Series Procurement High Beta Fabrication 570 MeV Installation Phase 1 CS Network Operational Instrument Selection - Decision 3 Instruments ready for Comm. Innstr 16 Constr & Inst. 1st Call for User Proposals Installed for 2.0 GeV Installation Phase 2 Innstr 16 Cold Comm. 16 Instr

4 ESS Linac Evolution

5 New Baseline New Baseline Headline Parameters: 5 MW Linac 2.0 GeV Energy (30 elliptical cryomodules) 62.5 ma beam current 4% duty factor (2.86 ms pulse length, 14 Hz) First beam by 2019 (1.0 MW at 570 MeV) The new baseline was achieved by: Increasing beam current by 25% Increasing Peak Surface Field by 12% Setting High Beta b g to 0.86 Adopting maximum voltage profile Adopting a uniform lattice cell length in the elliptical section to permit design flexibility schedule flexibility. 5

6 Linac Design Choices User facilities demand high availability (>95%) ESS will limit the peak beam current below 65 ma Linac Energy > 2 GeV to accomplish 125 MW peak power. Front end frequency is 352 MHz (CERN Standard) High energy section is at 704 MHz 6

7 Ion Source and NC Linac The RFQ and DTL will be similar to the CERN Linac4 design. The RFQ: 4.5 m long Energy of 3.6 MeV The DTL: Will consist of five tanks Tank length ~7.5 m Final energy of 88 MeV Six klystrons: Operating at 352 MHz Max. saturated power of 2.8 MW Duty factor of 4% Prototype proton source operational, and under further development, at ESS-Bilbao (Spain). Output Energy 75 kev. Design exists for ESS RFQ similar to 5m long IPHI RFQ at CEA-Saclay (France). Energy 75 kev -3.6 MeV. Picture from CERN Linac4 DTL. DTL design work at ESS and INFN-Legnaro (Italy), Energy MeV. 7 Design work at ESS-Bilbao for MEBT with instrumentation, chopping and collimation.

8 Spoke Cavities Superconducting double-spoke accelerating cavity, for particles with b=0.5, energy MeV. ESS will be the first accelerator to use 352 MHz double spoke cavity resonators. Design performed by CNRS-IN2P3 (France). 28 cavities with an accelerating gradient of 9 MV/m, requiring 320 kw peak power. What type of power source to choose? Tetrode Klystron IOT Solid State First IN2P3 in Oct

9 Elliptical Cavities Universal Cryomodule: Cryomodules are expensive and difficult to fabricate. Pick cavity b and number of cells: Optimize power transfer Optimize length Power in couplers is limited to 1200 MW (peak). Cavity and cryomodule design well advanced at CEA-Saclay (France). Medium b = cell cavities Cavity length = 0.86 m 32 cavities in 8 cryomodules Maximum peak RF power = 800 kw High b = cell cavities Cavity length = 0.92 m 88 cavities in 22 cryomodules Maximum peak RF power = 1100 kw 9

10 10 Universal Cryomodule

11 First Test of ESS high-b Prototype Cavity Expected in vertical cryostat Rs = 9 nw Test limited by RF amplifier (saturation at 190 W) and high X-ray level Specification in cryomodule No quench observed Vertical test done the 22th of May 2014 at CEA Saclay Next plans: Measurement of resonant frequency of 1st bandpass mode at 2K Measurement of resonant frequency of HOM at 2K If possible, increase accelerating field up to the quench limit Perform heat treatment at CERN at 650 o C under vacuum 11 11

12 Spoke Linac (352 MHz) RF System Layout 26 Double Spoke cavities Power range kw Combination of two tetrodes Other options: Solid State Amplifiers Large power supply (330 kva) to supply 8 stations (16 tetrodes) 12

13 ESS Linac RF System 13 Each ESS cavity to be individually powered: 36 med-b amplifiers (klystrons) 84 high-b amplifiers (IOTs/klystrons) Total 120 high power RF amplifier systems delivering 1.1 MW each! 4 amplifiers per modulator anticipated.

14 Elliptical (704 MHz) RF System Layout Klystrons Racks and Controls Modulator WR1150 Distribution Cells of 8 klystrons for Med-b 10.5 Cells of 8 klystrons (IOTs) for High-b

15 ESS Cryogenics Three cryogenic plants: Accelerator: K, K - plus 8 g/s helium liquefaction Target: - ~ 20 16K Test & Instruments - ~ 250 W@ 4.5 K K Distribution system: Permits independent cool down & warm up of cryomodules, likely IKC Cryoplant orders to be placed in 2015 with operations starting in 2017/18 Valve box Cryoline Jumper connection Cryomodule 15

16 ESS Beam Diagnostics Beam Loss Monitor Beam Current Monitor Beam Position Monitor Slit (H & V) Grid (H & V) Faraday Cup Wire Scanner Non-Invasive Profile Monitor Optical Imaging Halo Monitor LEBT MEBT DTL Spoke Med-b High-b Upgrade High-b A2T DumpLine TOTAL Day 1 Day 1+ Note: These numbers were the result of an scope reduction from the initial diagnostics to meet budget targets. Still need to be confirmed by beam physics studies and commissioning planning. Bunch Shape Monitor 16

17 Diagnostics In-Kind Status BLM (IC) BCM BPM FC EMIT WS/Halo IPM Lumi/BIF BSM Imaging SEM TC LEBT MEBT DTL Spoke MBE HBE HEBT A2T BLD procurement with CERN DAQ BLD Bilbao DAQ BLD Bilbao Legnaro DAQ BLD procurement Bilbao DAQ BLD Saclay Bilbao DAQ Saclay Bilbao BLD Bilbao DAQ BLD DAQ BLD Bilbao DAQ BLD Bilbao DAQ Bilbao BLD DAQ BLD DAQ BLD DAQ Overarching agreement exists, technical details/specification to be refined Discussions with potential partner ongoing (e.g. DESY, Trieste, Legnaro, CI, RAL/ISIS, PSI, GSI ) 17

18 Linac Warm Section Layouts BPMs BPMs BSM BCT WS BIF BPMs WS BPMs IPM 18

19 Diagnostics Prototypes Position Monitors Current Monitors 19

20 ESS Integrated Control System The ESS Control System is a complex network of hardware, software, and configuration databases that integrate the operations of the Accelerator, Target, Instruments and Conventional Facility infrastructure. Hardware platforms MicroTCA High performance applications such as fast signal processing EtherCAT Distributed, khz range acquisition PLC Low-end I/O, interlocking, etc. Software EPICS Used for control of the entire facility(some offline use of LabVIEW) CS-Studio Generic user interface tool (GUI, Alarms, Archiving) DISCS Distributed Services for Controls (databases, configuration, ) 20 20/

21 ESS Control System Work Packages The ESS Cost Book lists 39 separate control system work packages, 30 of which include provision for a significant In-Kind contribution. In addition, many other technical work packages either include a requirement for a control system interface or are interested in adding this as an option. The main areas covered are: Application software Development of application, frameworks and toolkits Core Software Databases, software tools and services Core Hardware Development of timing system and control boxes Equipment Supply of computer/electronics hardware Infrastructure Control room, data centre and network equipment Integration Support Integration of Accelerator, Target and Conventional Facilities 21 21/

22 What s Happening Now? Accelerator areas being investigated: RF: SRF elliptical cavity procurement (med-b and high-b), test and delivery: STFC ASTeC/Technology. RF Distribution systems: Huddersfield University. Diagnostics: Target diagnostic imaging: Liverpool University, STFC ISIS Other diagnostic systems being discussed: Liverpool University, STFC Technology/ISIS. Vacuum: Vacuum component test facilities (incl. Controls): STFC ASTeC/Technology. Design and supply of Linac Warm Units (incl. Controls): STFC ASTeC/Technology. Controls: EPICS for Freescale PowerPC P2020 FPGA controllers: STFC Technology Timing and Event EPICS applications: STFC Technology Other control system areas: STFC Technology/ISIS 22

23 23 RF & Vacuum

24 Diagnostics & RF Targetry Beam Imaging RF Distribution Spoke Distribution Elliptical Distribution C Welsch (Liverpool University & opac) 24 R Edgecock (Huddersfield University)

25 UK Opportunities RF: High power amplifiers Klystrons, IOT s or SSA s. RF distribution systems. RF control systems. Cryogenics: Cryogenic distribution systems. Diagnostics: Diagnostic device production (wide variety). DAQ/Interfacing. Vacuum: Pumps, controllers, gauges Controls: I/O controllers, DAQ units, software development. Generic: Cabling 25

26 ACCSYS update in-kind discussions Potential partners identified for 47% of the total planned/potential in-kind value, contracting under way! Planned/potential in-kind is 78% of accelerator budget Many activities start 2014, reflecting the importance of reaching agreements soon 26 Håkan Danared, ACCSYS in-kind manager 26