Diamond Light Source Interest in FELs R. Bartolini

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 Beamline 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
Phase 2: 3 GeV Linac
Free-Electron Laser
Phase 3: ~ 6 GeV Linac Free-Electron Laser
300 eV – 12 keV (i=5)
300 eV – 12 keV (i=5)
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)
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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)
Put forward the idea of a
“Swiss-FEL+” normal
conducting machine which
was adopted for the
response to BIS.
Energy ~ 8.7 GeV
Peak photon energy ~ 18.6 keV
Gap tuneable e.g. ~ 5.5 -16.5 keV
Repetition rate ~ 100 Hz
Initial no. of FELs ~ 2
Possible no. of FELs ~ 4
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;
detectors;
lasers and auxiliary light sources;
diagnostics;
sample environment and target delivery;
simulation, control, data acquisition, data analysis, and
storage.”
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Diamond can
contribute to
these
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
3rd harmonic cavity
diagnostics
accelerating modules
laser heater
BC
1
Astra/PARMELA
Impact-T
BC2
BC3
spreader
collimation
FELs
Elegant/IMPACT/CSRTrack
GENESIS/GINGER
•
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
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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 and stress analysis of DDBA vacuum component
• Thermal (ANSYS)
– Vacuum Controls and Interlocks
• EPICS
• PLC
• Automated bakeout systems
EPICS control screen for RF
cavity straight
• Automated pumping and venting systems
Thanks to M. Cox (DLS)
Automated PLC-based
bakeout rack for DDBA
Diamond Technical capabilities: Vacuum
• Processing / assembly / testing
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UHV cleaning
Clean UHV assembly
Vacuum bakeout and NEG coating activation
Helium leak testing
Materials and components testing (outgassing, leak rate)
Pump and gauge characterisation and testing
Clean assembly
• Operations
– System monitoring
– Maintenance and repairs
Test rig for outgassing
measurements
Bakeout
Gauge test rig
5m long NEG-coated vessel
installed and activated
Clean installation
Diamond Technical capabilities: Diagnostics
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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
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80 kW IOTs driving storage ring 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
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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,
continuous scanning
• Real-time feedback system
design for example position, tune,
emittance, TMBF, LMFB
• Distributed timing information to
psec resolution
• High integrity PSS design and
operation to IEC61508
Distributed Control Systems Architecture
TMFB
Controller
Dispersion
FB Controller
Orbit FB
Controller
Coupling FB
Controller
Tune FB
Controller
Tune FF
Controller
Emit Y
Emit.
Camera
Thanks to M. Heron (DLS)
Pos X,Y
pBPM
pBPMs
Master
Osc
Optics FF
Controller
Pos X,Y
Gap
Tunes X, Y
eBPM
TMBF
ID
172 eBPMs
Buttons
Insertion Device
Orbit FF
Controller
RF
Amp
Corrs local
to ID
Quads
local to ID
248 Quads
96 Skew
Quad
172 Corrs
on Sext
RF Cavity
Strip lines
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:
• Nature 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
www.sfx-consortium.org
Germany, UK, Sweden, Slovakia,
Switzerland, USA, Australia
[email protected]
• 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
• Facilitate complementary experiments at
• Diamond Light Source (and other synchrotrons)
• Central Laser Facility
• electron Bio-Imaging Centre (eBIC)
• Several principal beamline scientists at
Diamond Light Source already participate in
dozens of XFEL experiments
• This typically involves deep collaborations with
larger groups of scientists and engineers in
the UK, Europe, USA, Asia, and Australia
Germany, UK, Sweden,
Slovakia, Switzerland,
USA, Australia
Current and anticipated XFELs
• LCLS (USA) in operation
• SACLA (Japan) in operation
• PAL XFEL (Korea) 2016
• SwissFEL (Switzerland) 2017
• European XFEL (Germany) 2017
• LCLS-II (USA) 2019
Diamond PBSs interest: (S. Dhesi – I06 – Soft Xray Science)
M. Först et al., Nat. Mater. 14, 883 (2015)
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
how that the disruption of the AFM ordering
proceeds electronic ally. The work was performed
on I06 at Diamond and at the LCLS.
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
focussed to small spot
Why X-FELs for Inelastic X-ray Scattering?
(unlike echo
• High average flux
• 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 –
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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 –
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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
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#3: Electron Beam Transport Simulation and
Optimization
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#4: FEL Output Simulation and Optimization
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#5: Electron & Photon Diagnostics
#6: Synchronisation
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Diamond
can
contribute
to these
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
Facility
ISIS
(Spallation
Neutron Source)
Research Complex (for
users of Diamond, ISIS and CLF)
Diamond
Light Source
Thank you for your attention!