Status of the ESS Accelerator

Workpackage

Peter McIntosh

STFC Daresbury Laboratory

UK‐ESS Interactions and Opportunities

Rutherford Appleton Laboratory

3 Dec 2014

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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!

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2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

ESS Program

Conventional

Facilities

Accelerator

Target

Neutron

Scattering

Systems

Integrated

Control Systems

Building

Commissioning

Concluding

Design

Design

Construction

Commissioning Design &

Prototyping Procurement

Installation

Commissioning

Design

Procurement

Installation

Commissioning

Installing

Construction Construction

Ground Break

First installations (of Machine Systems)

First Neutrons

Machine 2.0 GeV

Accelerator, Target, Aux, Office, Lab & Instr Bldngs*

570 MeV

Instrument Selection - Decision

Design

Commissioning

Construction

Design

Development

Commissioning CS Network Operational

3 Instruments ready for Comm.

Initial Operation Initial Operation

Installed for 2.0 GeV

16 Instr

End Of Construction Start Of Construction

Concept

Devlopment

Licensing Preliminary Design Acccelerator Bldngs

Detailed Design Accelerator Bldngs

Earth Works

G01 Linac Tunnel G02 Klystron Bldng

Cryo Kompressor Bldng

Medium Beta Fabrication Spoke Series Procurement

High Beta Fabrication

Installation Phase 1

Installation Phase 2

Innstr 16 – Cold Comm.

Innstr 16 – Constr & Inst.

Top-Level ESS Project Schedule

1st Call for User Proposals

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ESS Linac Evolution

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1992

2013

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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 bg to 0.86

– Adopting maximum voltage profile

– Adopting a uniform lattice cell length in the elliptical section to permit

• design flexibility

• schedule flexibility.

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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

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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.

Design work at ESS-Bilbao for MEBT with instrumentation, chopping and collimation.

DTL design work at ESS and INFN-Legnaro (Italy), Energy 3.6 - 90 MeV.

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% Picture from CERN Linac4 DTL.

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Spoke Cavities

• Superconducting double-spoke

accelerating cavity, for particles with

b=0.5, energy 90 - 216 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 cavity @ IN2P3 in Oct 2014

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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 = 0.67 – 6 cell cavities

– Cavity length = 0.86 m

– 32 cavities in 8 cryomodules

– Maximum peak RF power = 800 kW

• High b = 0. 86 – 5 cell cavities

– Cavity length = 0.92 m

– 88 cavities in 22 cryomodules

– Maximum peak RF power = 1100 kW

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Universal Cryomodule

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First Test of ESS high-b Prototype Cavity

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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 650oC under vacuum

Test limited by RF amplifier

(saturation at 190 W) and

high X-ray level

Specification in

cryomodule

Expected in vertical cryostat

No quench observed

Rs = 9 nW

Vertical test done the 22th of May 2014 at CEA Saclay

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Spoke Linac (352 MHz) RF System Layout

26 Double Spoke cavities

Power range 280 - 330 kW

Combination of two tetrodes

Other options:

Solid State Amplifiers

Large power supply (330 kVA) to

supply 8 stations (16 tetrodes)

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ESS Linac RF System

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.

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4.5 Cells of 8 klystrons for Med-b

10.5 Cells of 8 klystrons (IOTs) for High-b

WR1150 Distribution

Klystrons

Modulator Racks and Controls

Elliptical (704 MHz) RF System Layout

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Valve

box

Cryoline

Jumper

connection

Cryomodule

ESS Cryogenics

Three cryogenic plants:

• Accelerator: - 3.1 kW @ 2K,

- 12.8 kW @ 40 - 50 K

- plus 8 g/s helium liquefaction

• Target: - ~ 20 kW @ 16K

• Test & Instruments - ~ 250 W@ 4.5 K

- 200 W @ 40K

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

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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

Bunch

Shape

Monitor

LEBT 0 2 0 1 2 1 0 0 0 0 0

MEBT 0 4 6 1 1 1 4 2 0 0 1

DTL 15 7 15 0 0 2 1 1 0 0 1

Spoke 39 0 26 0 0 0 1 1 0 0 0

Med-b 27 1 18 0 0 1 3 3 0 0 1

High-b 63 1 42 0 0 0 1 1 0 0 0

Upgrade

High-b 67 2 44 0 0 0 4 1 0 0 1

A2T 19 2 11 0 1 0 3 3 2 3 0

DumpLine 6 2 3 0 0 0 0 0 1 1 0

TOTAL 236 21 165 2 4 5 17 12 3 4 4

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.

Day 1 Day 1+

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LEBT MEBT DTL Spoke MBE HBE HEBT A2T

BLM (IC) BLD

DAQ

BCM BLD

DAQ

BPM BLD

DAQ

FC BLD

DAQ

EMIT BLD

DAQ

WS/Halo BLD

DAQ

IPM BLD

DAQ

Lumi/BIF BLD

DAQ

BSM BLD

DAQ

Imaging BLD

DAQ

SEM BLD

DAQ

TC BLD

DAQ

Diagnostics In-Kind Status LEBT MEBT DTL Spoke MBE HBE HEBT A2T

BLM (IC) BLD procurement with CERN

DAQ

BCM BLD Bilbao

DAQ

BPM BLD Bilbao Legnaro

DAQ

FC BLD procurement Bilbao

DAQ

EMIT BLD Saclay Bilbao

DAQ Saclay Bilbao

WS/Halo BLD Bilbao

DAQ

IPM BLD

DAQ

Lumi/BIF BLD Bilbao

DAQ

BSM BLD Bilbao

DAQ Bilbao

Imaging BLD

DAQ

SEM BLD

DAQ

TC 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 …)

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Linac Warm Section Layouts

WS

IPM

BPMs

BPMs BPMs

BPMs

WS BIF

BCT BSM

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Diagnostics Prototypes

Position Monitors Current Monitors

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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, …)

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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/

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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

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RF & Vacuum

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Diagnostics & RF

Targetry Beam Imaging

C Welsch (Liverpool University & oPAC)

RF Distribution

Spoke Distribution

Elliptical Distribution

R Edgecock (Huddersfield University)

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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

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ACCSYS update in-kind discussions

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• 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

Håkan Danared, ACCSYS in-kind

manager