STFC ASB/IoP PAB Workshop - Towards a UK XFEL

Diamond Light Source Interest in FELs R. Bartolini (on behalf of R.P. Walker and Diamond Technical Division) Outline

• Diamond’s interest in FELs 2006-2016

• Diamond Technical Groups capabilities towards an XFEL Accelerator Physics and FELs, IDs, Diagnostics, Engineering, Vacuum, RF

• Diamond Principal Scientists interest in XFELs XFEL hub, Soft Xrays, Inelastic Xray scattering, Powder diffraction, THz, …

• Possible contribution to a new initiative 2006-2007: Sapphire - in response to a request from our Science Advisory Committee to consider possibilities for producing short pulses

SAC Mar. 2007: “The SAC felt that there was a brilliant science case for the femtosecond work” “The SAC felt that the Linac was the exciting option”

A Phased Approach to Short Pulse X-ray Radiation Phase 1: 3 GeV Linac Spontaneous Radiation 300 eV – 12 keV (i=5) Phase 2: 3 GeV Linac Free- Laser 300 eV – 12 keV (i=5) Phase 3: ~ 6 GeV Linac Free-Electron Laser 300 eV – 12 keV (i=1)

2008-2010: New Light Source

Very strong and effective collaboration between ASTeC & Diamond (and others).

Diamond contributed in particular to: - Coordination (Source Manager) - Stage 1 RF gun design - Electron beam gun & linac optimization - FEL studies - Layout and engineering - Diagnostics - Radiation safety 2009 FEL conference The NLS work gained wide international visibility and high scientific standings 2010-2011: post NLS - X-band option (1 kHz)

 From the beam dynamics point of view, an X-band linac operating at ~ 20 MV/m is a suitable driver for a soft X-ray seeded FEL facility, giving similar performance to the NLS baseline.

2014: Response to BIS Capital Consultation Exercise (April-July 2014) Energy ~ 8.7 GeV Peak photon energy ~ 18.6 keV Put forward the idea of a Gap tuneable e.g. ~ 5.5 -16.5 keV “Swiss-FEL+” normal Repetition rate ~ 100 Hz conducting machine which Initial no. of FELs ~ 2 was adopted for the Possible no. of FELs ~ 4 response to BIS. Total length ~ 850 m Power ~ 7 MW Cost < £450m (to be confirmed !)

http://ukfel.org/wordpress/wp-content/uploads/2014/07/UKX.pdf

UK X-ray FEL Facility Overview “In this brief document we present the case for building a UK-based X-ray Free Electron Laser facility. This case, prepared for submission as input to the UK Government consultation on the UK’s scientific infrastructure, has been endorsed by over 400 active scientists and technologists“

Possible site for UK-FEL at RAL to allow co-location with high power lasers for High Energy Density Science and Shock Physics (see response to BIS Capital Consultation)

2016: Start of a New Initiative ? draft FEL Strategy presented to Science Board Feb. 11th 2016 “The time taken from fully committing to the construction of a UK FEL facility to it being operational is likely to be at least six years. The final decision on whether to build an X-ray FEL in the UK and to what specification to build could be taken in five years, around 2020.”

Long enough … UK-FEL LCLS-II

EU-XFEL

LCLS

“To prepare for this decision in five years’ time the following actions are recommended in parallel with the development of the community (see Figure 4): • initiate a programme to define the specification that is required and prepare preliminary costings;  • develop a fully coordinated FEL R&D programme, building upon existing expertise in the following areas: accelerators;  Diamond can detectors;  contribute to lasers and auxiliary light sources; these diagnostics;  sample environment and target delivery;  simulation, control, data acquisition, data analysis, and storage.” 

Diamond Technical capabilities: Accelerator and FEL design

UK NLS: 2.25 GeV SC CW linac L- band

High brightness electron gun operating (initially) at 1 kHz experimental stations gas filters

IR/THzundulators photoinjector diagnostics 3rd harmonic cavity accelerating modules spreader laser heater collimation BC BC2 BC3 1 FELs

Astra/PARMELA Elegant/IMPACT/CSRTrack GENESIS/GINGER Impact-T • Tracking studies to optimise the beam quality at the beginning of the undulators: peak current, slice emittance, slice energy spread

• linac simulations include CSR, longitudinal space charge, wake-fields in RF cavities

• Validation with full start-to-end simulation Gun to FEL (time dependent) Diamond Technical capabilities: Accelerator and FEL design Tailoring the 6D phase space to optimise the UK NLS FEL performance (slice control and jitter studies)

Diamond Technical capabilities: Accelerator and FEL design

R. Bartolini Future Light source workshops 2010 SLAC

Generation of attosecond pulses

More complex schemes in A. Seryi’s talk

Diamond Technical capabilities: IDs • ID specifications & simulations • Magnet design • Mechanical design • Cryogenic design • Assembly (machining, metrology and UHV) • Field measurements and shimming (Hall probe, coils, stretched wire benches) • Installation and commissioning • Beamline user support • ID development (CPMUs and SCUs)

Measuring bench and shimming

Thanks to S. Milward (DLS)

In house capabilities - I05 helical undulator

Diamond Technical capabilities: Vacuum

• Vacuum Group 14 people – 5 Engineer/scientist – 9 Technical • Design

– Vacuum simulations Analytical multi-gas vacuum simulation for DDBA Comsol™ angular coefficients vacuum simulation of DDBA • Analytical (In-house code) NEG pumping port • Monte Carlo (Synrad, Molflow, Comsol™) • Angular Coefficients (Comsol™) – Vacuum Engineering FEA • Mechanical (ANSYS) • Thermal (ANSYS) Thermal and stress analysis of DDBA vacuum component – Vacuum Controls and Interlocks • EPICS • PLC

• Automated bakeout systems EPICS control screen for RF • Automated pumping and venting systems cavity straight Automated PLC-based Thanks to M. Cox (DLS) bakeout rack for DDBA

Diamond Technical capabilities: Vacuum

• Processing / assembly / testing – UHV cleaning – Clean UHV assembly – Vacuum bakeout and NEG coating activation – Helium leak testing Clean assembly – Materials and components testing (outgassing, leak rate) – Pump and gauge characterisation and testing • Operations – System monitoring – Maintenance and repairs Bakeout

Test rig for outgassing Gauge test rig 5m long NEG-coated vessel Clean installation measurements installed and activated Diamond Technical capabilities: Diagnostics • Transverse Profile/Emittance: screens (YAG/OTR), SR light monitors, X-ray pinhole cameras • Cavity Beam Position Monitors: Experimental System of CBPMs developed and installed, including prototype acquisition electronics (collaboration with JAI@RHUL) • Micro-bunching diagnostics: mm-wave sensors, characterisation of emission spectra (collaboration with JAI@RHUL) • Expertise in beam stability: characterisation of vibration and drift sources, feedback loops for stabilisation of orbit, tune, emittance, x-ray beams, coupled bunch instabilities… • FPGA/software development: Many relevant projects realised in house (FOFB, TMBF, CBPM)

Cavity BPM installation in the booster tunnel (DLS + JAI@RHUL)

Thanks to G. Rehm (DLS)

Diamond Technical capabilities: RF

100 MeV pre-injector linac 80 kW IOTs driving cavities

• Diamond has operated reliably for users since 2007 • High power RF linac • Normal conducting, driven by pulsed 37 MW klystrons • 300 kW CW cavities in storage ring • Superconducting, driven by multiple 80 kW Inductive Output Tubes • Cryogenic experience with 500 MHz SC RF cavities • LLRF and electronics • Test facilities for high power RF Thanks to C. Christou (DLS)

Diamond Technical capabilities: RF

A 3 GHz photocathode RF gun has been designed built and tested • Low-power cold tests have measured coupling and resonant frequency • Bead-pull measurement has verified field calculation • High power testing and conditioning has been carried out in-house

E/M model of dual-feed RF gun Completed RF gun Fully designed RF gun assembly

The S-band programme for the UK NLS that has been downscaled after the cancellation of NLS. A second iteration of the design is however under construction

Diamond Technical capabilities: Engineering

• Civil engineering • Mechanical and electrical engineering • Design and engineering integration • Survey and alignment • Stability (thermal, vibrations, power supply, …) • FEA • …

Thanks to J. Kay (DLS)

Diamond Technical capabilities: Engineering

Diamond Technical capabilities: Controls

• Design, development and operation of distribute control systems based on EPICS for accelerator and experiment control • Software design, development, testing, and deployment • FPGA design and developed for example TMBF, BPMs, DLLRF, low latency communication, Distributed Control Systems Architecture continuous scanning TMFB Controller

Dispersion • Real-time feedback system FB Controller Orbit FB design for example position, tune, Controller Coupling FB emittance, TMBF, LMFB Controller Tune FB Controller • Distributed timing information to Tune FF Controller Master Optics FF Osc psec resolution Emit Y Controller Pos X,Y Emit. Orbit FF RF pBPM • High integrity PSS design and Pos X,Y Tunes X, Y Gap Controller Amp operation to IEC61508 eBPM TMBF ID

Camera pBPMs 172 eBPMs Buttons Insertion Device Corrs local Quads 248 Quads 96 Skew 172 Corrs RF Cavity Strip lines to ID local to ID Quad on Sext

Thanks to M. Heron (DLS) Real-time Feedback Applied to Diamond

Diamond Technical capabilities: beamline optics

Optics & Metrology Group • World-class facilities and expertise (~10 experienced scientists) • Optics Design (both ray tracing and wave-front propagation) • Metrology laboratory: state of the art instruments capable of measuring <50nrad optics • B16 Test beamline: for testing and development of novel optics • Nano-focusing optics: development of both mirrors and lenses • Adaptive Optics: extensive experience with Bimorph mirrors • At-wavelength (i.e. using X-rays) metrology on B16: provides unprecedented <10nrad optics measurement capability • Publications by Group’s scientists: ~80 in last 8 years - many in high-impact journals: • Scientific Reports, Phy. Rev. Lett., Appl. Phys. Lett., Optics Letters, Optics Express, Physical Review A & B, ...

Thanks to K. Sawhney (DLS) European XFEL Hub at Diamond

[email protected] www.sfx-consortium.org Germany, UK, Sweden, Slovakia, Switzerland, USA, Australia • Hub is part of the SFX consortium at Eu-XFEL • To help facilitate (time-resolved) serial structural biology experiments via sample preparation, delivery, data collection, and processing www.sfx-consortium.org • To exploit rapidly evolving XFEL methods that are complimentary and synergistic across XFEL, synchrotron, and cryo-EM sources • Using LCLS now, Eu-XFEL and probably others in the future Germany, UK, Sweden, Slovakia, Switzerland, • Facilitate complementary experiments at USA, Australia • Diamond Light Source (and other synchrotrons) • Central Laser Facility • electron Bio-Imaging Centre (eBIC) Current and anticipated XFELs • Several principal beamline scientists at • LCLS (USA) in operation Diamond Light Source already participate in • SACLA (Japan) in operation dozens of XFEL experiments • PAL XFEL (Korea) 2016 • This typically involves deep collaborations with • SwissFEL (Switzerland) 2017 larger groups of scientists and engineers in • European XFEL (Germany) 2017 the UK, Europe, USA, Asia, and Australia • LCLS-II (USA) 2019 Diamond PBSs interest: (S. Dhesi – I06 – Soft Xray Science) Soft x-ray spectroscopy and diffraction are used to understand out-of-equilibrium phenomena in strongly correlated systems. The effects of charge-redistribution following excitation with a femtosecond laser pulse can be tracked in exquisite detail

using an optical pump- XFEL probe technique.

Temporal evolution of the antiferromagnetic (AFM) order in a nickelate thin film following phonon excitation in the substrate. The ultrafast changes in the lobes (yellow circles) were used to show

., Nat. Mater. 14, 883 (2015) Mater. Nat. ., how that the disruption of the AFM ordering

et al et proceeds electronic ally. The work was performed

on I06 at Diamond and at the LCLS. M. Först Först M.

Source requirements for soft x-ray science: Soft x-ray source with complete control of polarisation Shot to shot control of wavelength down to <0.1% of bandwidth >10^12 photons per pulse Repetition rate ~1kHz Ultrashort pulses (down to 1 fs) Diamond PBSs interest: (S. Collins – I16) Ultra high resolution inelastic Xray scattering • Millivolt x-ray spectrometers provide valuable information about dynamics over nanoscale distances and ps timescales • Current spectrometers are highly inefficient and require 25-30 keV x-rays New spectrometer concepts (Xray chirping spectrometer)

• Takes advantage of ~ 10 fs pulses to disperse in the time domain. • The beam can be Why X-FELs for Inelastic X-ray Scattering? focussed to small spot • High average flux (unlike echo • High average spectral flux (10-100 meV) with seeding? spectrometer) • Photon energy (<10 keV max) well matched to new spectrometer concepts • Combine IXS with pump/probe • Allows dispersion in time domain (chirping spectrometer) Diamond PBSs interest: ultra fast powder diffraction (C. Tang – I11)

Ultrafast Lattice Dynamics and Excitations –

• Vibrational relaxation and phonon distortions in nano-composites • Spin dynamics-structural correlation in ferromagnetic materials • Shock-wave structural impacts and alternations • Strongly correlated-electron materials (superconductivity, colossal magnetoresistance)

Femto-second Chemistry –

• Laser pump-probe excitation and ultra dynamics of chemical bonds • Photoexcitation phase transitions and thermoacoustic phenomena • Ultrafast electronic transfer in Li-ion battery materials • Energy transfer in photo-chemistry • Molecular cage formations in nano-porous frameworks. Diamond PBSs interest: (G. Cinque – B22) using the spent e- beam after FEL i.e. a la TERAFERMI scheme

From A. Perucchi – ELETTRA, TERAFERMI: A THz Beamline at the Fermi-FEL in Workshop on Terahertz, July 2012 Argonne National Laboratory Conclusions: FEL Accelerator R&D Work Packages

#1: Gun development 

#2: RF 

#3: Electron Beam Transport Simulation and  Optimization Diamond can #4: FEL Output Simulation and Optimization  contribute to these #5: Electron & Photon Diagnostics 

#6: Synchronisation

Conclusions Diamond is the largest accelerator facility in the UK with a thriving users community and a strong multidisciplinary technical workforce. It is in an ideal position to provide a coherent contribution to R&D effort towards a new UK FEL, across a wide range of disciplines covering accelerator & FEL physics, engineering & vacuum, optics, detectors, end stations, computing etc Central Laser ISIS Facility (Spallation Neutron Source) Research Complex (for users of Diamond, ISIS and CLF)

Diamond Light Source Thank you for your attention!