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CALIFES-Based Beam Facility. W. Farabolini K. Yaqub. Contents. CALIFES today Present uses of CALIFES Beam test of the accelerating structure Beam Instrumentation tests Possible evolutions . CTF2/CTF3 overview. Dog-leg experiment. Stand-alone test stand. PHIN gun.
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CALIFES-Based Beam Facility W. Farabolini K. Yaqub W. Farabolini - CLIC Workshop 2014
Contents • CALIFES today • Present uses of CALIFES • Beam test of the accelerating structure • Beam Instrumentation tests • Possible evolutions W. Farabolini - CLIC Workshop 2014
CTF2/CTF3 overview Dog-leg experiment Stand-alone test stand PHIN gun W. Farabolini - CLIC Workshop 2014
CLEX experimental hall PB DB TBL 8 m 42 m W. Farabolini - CLIC Workshop 2014
CALIFES today F. Peauger et al., Proceedings of LINAC08, Victoria, BC, Canada W. Farabolini - CLIC Workshop 2014
CALIFES Performances A very easy to operated LINAC (by users themselves) W. Farabolini - CLIC Workshop 2014
The Two-Beam Test stand Presently PB Dmitry Gudkov And after CLIC module installation (June 2014) DB W. Farabolini - CLIC Workshop 2014
Extensively instrumented test stand 2 phase shifters 1 variable splitter 1 FCU 1 Flash box 2 screens 3 PMTs 16 WFMs channels 15 RF channels (Diodes and IQ) Thermal probes and flow rate W. Farabolini - CLIC Workshop 2014
Test of 12 GHz accelerating structures performances RF On Power fluctuations Phase scan RF Off Califes beam on the final spectrometer Energy gain for various RF phases Require to master: timing and phase between beams, phase between structures, power and phase measurement accuracy, energy measurement accuracy. ESSENTIAL PERFORMANCE VALIDATED for CLIC W. Farabolini - CLIC Workshop 2014
Beam kick during Breakdown Beam before BD 0.68 mm Beam after BD On YAG screen without BD With BD Time resolved position on cavity BPM Results in accordance with SLAC measures A. Palaia PhD Thesis EXPERIMENTS WORTH to be CONTINUED with much more statistics W. Farabolini - CLIC Workshop 2014
Why it is so important for CLIC ? M. Jonker Example exercise: • Most restrictive structure: Collimators (200 μm opening of spoilers). • Potential damage: Destruction of spoilers • In the present design spoilers are consumables: 1 hit – you're out! • If we can use spare surface (8mm), fully consumed after 1 – 10?? impacts (depending on the severity). • Derive maximum kicks, displacements, transverse RF in the Main Linac corresponding to 100 μm. • Note: to kick any of the other sensitive structures (accelerator structures, vacuum chamber) the required kicks are 2 orders of magnitude larger! • However, in addition to a dipole kicks, a break down may also contain higher order modes, leading to a blow-up of the beam (which is beneficial). W. Farabolini - CLIC Workshop 2014
Wakefield Monitors studies 0.12 mm Without RF power ACS with WFM F. Peauger Position scan with corrector With RF power • Already promising results (misalignment between the 2 ACS detected and corrected) • Electronics completed recently • Performances at nominal power still to be assessed EXPERIMENT to be RESUMED during next Run with nominal RF Power W. Farabolini - CLIC Workshop 2014
Why it is so important for CLIC ? Impact of Wakemonitors D. Schulte Single machine shown With no wakemonitors With wakemonitors • Goal is to keep emittance growth due to wakefields below 1nm • Average emittance growth with no wakemonitor is about 40nm • Sensitive to prealignment, girder accuracy, structure accuracy etc. • With wakemonitor we find about 0.5nm • Only sensitive to accuracy of structure and on electronics W. Farabolini - CLIC Workshop 2014
Octupolar field study For very weak RF power (few MWs, uncertain phase) At zero-crossing (rising RF power side), 25 MW At zero-crossing (falling RF power side), 25 MW Ray-tracing model through octupolar fields “Multipoles of the accelerating field and the beam distortion in TBTS”, Alexej Grudiev, 29/05/2013 CLIC RF Structure Development Meeting EXPERIMENT to be RESUMED during next Run with well calibrated power to benchmark the Panofsky-Wenzel and Lorentz force models W. Farabolini - CLIC Workshop 2014
Beam profiles studies “Measurement of transverse coupling in the TBTS, Christopher Borgmann, 22. October 2013, CLIC/CTF3 Exp. Verification meeting” EXPERIMENT to be RESUMED during next Run W. Farabolini - CLIC Workshop 2014
CALIFES used for testing beam diagnostics W. Farabolini - CLIC Workshop 2014
EOS for bunch length measurement Rui Pan (PhD student), Electro-0ptical Bunch Profile Measurement at CTF3 IPAC’13 MOPME077. Inside CLEX optical tables for laser beam injection Electron bunch synchronous with laser pulse W. Farabolini - CLIC Workshop 2014
Test of high resolution BPMs F. Cullinan (PhD student), J. Towner A Prototype Cavity Beam Position Monitor for the CLIC Main Beam, IBIC'12 MOPA18 Cavity BPM installed on CALIFES line Position and beam charge linearity W. Farabolini - CLIC Workshop 2014
Why it is so important for CLIC ? Main Beam Cavity BPM T. Lefevre • High luminosity foreseen for CLIC requires small beam size at the IP (nm regime) -> low emittancebeam transport throughout the linac • Dispersion free steering minimizes emittance growth.Concept: • Apply an energy chirp along the beam pulse • Dispersive effects can be detected within the same beam pulse, independent from jitter, starting conditions, etc. • BPM requirements: • High spatial and temporal resolution simultaneously! • 50 nm spatial resolution requirement. • 50 ns requirement to make 2-3 position measurements within the 156 ns long bunch train. • Ultimate goal is demonstrate the combined spatial and temporal resolutions using a system of 3 BPMs in CTF3. • CALIFES is essential for this, as it can deliver beam with CLIC-like parameters. W. Farabolini - CLIC Workshop 2014
Test of beam loss monitors Electro-optic bunch profile monitor in CALIFES (CERN-Dundee University) F. Burkart, O. Stein, E. Nebot Del Busto Diamond beam loss detectors Sophie Mallows(PhD student),A fiber Based BLM System Research and Development at CERN, HB2012 THO3C05 W. Farabolini - CLIC Workshop 2014
Why it is so important for CLIC ? Quantity of LC Beam Instruments M. Wendt • Impressive quantities! • Calls for well though through engineering and optimization W. Farabolini - CLIC Workshop 2014
CALIFES: a very flexible beam 1, 2, 3… bunches with transverse space separation Streak camera measurements : s = 6.5 ps, S. Mazzoni Very small beam size 37 x 33 mm Califes Swiss FEL from Simona W. Farabolini - CLIC Workshop 2014
Califes for BI test Thibaut Proposal W. Farabolini - CLIC Workshop 2014
Califes for BI test • ‘’TéPaFou’ - A Beam Instrumentation Test Facility at CERN for CLIC but also for existing and future accelerators • with the present CERN accelerator schedule, every 3 years, we have 1-2 years long shutdown with no testing capabilities • Electron linac is the cheapest way to provide relativistic beams • Beam energy : more than 150MeV • Wish list for Beam parameters • Short and long bunches (100fs up to 200ps) • Large range of beam/bunch intensity • Possibility to study time to position correlation (Crabbing) • Photo-injector is a best way to provide a modular bunch spacing • Single bunch capability • Possibly bunch spacing similar to CERN beams (1ns, 5ns, 25ns, 50ns, .. ) • Pump – probe experiment (wakefieldstudy, impedance measurement, ..) W. Farabolini - CLIC Workshop 2014
Califes for BI test Machine layout to cover BI needs based on CALIFES Time to position correlation Large range of Bunch intensity Short and long bunches (100fs up to 200ps) Magnetic chicane Shorten or lenghthen • RF deflector • for crabbing Collimator Reducing the bunch intensity Beam position monitor Beam profile monitor Beam current monitor W. Farabolini - CLIC Workshop 2014
Califes for BI test Machine layout to cover BI needs based on CALIFES Synchrotron radiation test stand Under vacuum DUT area Synchrotron radiation test stand In-air DUT area • Including SR test stand for infrared, visible and UV light: Several port available • Including Testing area for beam instruments – Under Vacuum DUT • Including Testing area for particle detectors – In air DUT – low intensity option W. Farabolini - CLIC Workshop 2014
Califes for BI instrument test • Synchrotron radiation source • Testing optical detectors with short photon probes over a wide range of wavelength (IR, visible, UV) • Possible use for developing • Beam halo monitor, longitudinal density monitor, … • Under vacuum DUT area • Independent vacuum zone with easy access and pumping capabilities • Including steering magnets to move the beam around • Equipped with a Permanent instrumentation test stand • Used for beam cross calibration: beam size, position and bunch length • But also using ... • BTV station for screen and imaging system development • Pick-up for providing fast EM signal for testing electronic acquisition system • Coherent diffraction slit as a source for GHz-THz • Possible use for developing • Beam position monitor, Wall current monitor, fast beam transformer, Ionization gas monitor, Wire scanner… • In-air DUT area • Possibility to decrease the beam intensity to low or very low values • Possible use for developing Beam Loss monitors and Particle detectors • Study of MIP response, Time response study, Signal saturation studies, Space charge studies, Dose damage W. Farabolini - CLIC Workshop 2014
Possible evolutions of CLEX • Keep Califes alone for beam instrumentation test • Add an available S-band klystron • Add a chicane • Switch for the PHIN gun • Push the beam line toward the X-Box1 in CTF2 • Or transport the 12 GHz power to CLEX • Add an undulator, a Compton scattering experiment… • Add a 12 GHz crab cavity for bunch length diagnostic • Produce special beam for Wakefield study • 2 bunches of different energies with adjustable delay W. Farabolini - CLIC Workshop 2014
An additional klystron for CALIFES BOC Present Klystron Cradle for 2nd klystron W. Farabolini - CLIC Workshop 2014
Instrumentation line with chicane • A preliminary study has been done:“Short Pulse Capabilities of the Instrumentation Beam Line – V. Ziemann – 6 May 2010” • Short pulses (200 fs – 35mm) are necessary to mimic the CLIC main beam for instrumentation tests • Pulses of 20 mm are achievable with a chicane R56 = 2 cm and energy encoding of 10-3 , maximum energy reduced to 78% of the on crest one • All equipments will be available from the DB lines (magnets, powers, chambers…) W. Farabolini - CLIC Workshop 2014
Switch for PHIN gun PHIN gun and its spectrometer line W. Farabolini - CLIC Workshop 2014
CALIFES beam to CTF2 26.5 m 42 m 4.7 m Stand Alone Test Stand 8 m W. Farabolini - CLIC Workshop 2014
X-Box1 RF power to CLEX 26.5 m 42 m Low loss circular waveguide 4.7 m Stand Alone Test Stand 8 m W. Farabolini - CLIC Workshop 2014
Use of CALIFES for Wakefield tests First bunch second bunch N x 333 + variable delay(0-65) ps 70 o phase acceptance 65 ps Gun bunch charge as function of phase 3 GHz Accelerating field W. Farabolini - CLIC Workshop 2014
Summary of some possibilities W. Farabolini - CLIC Workshop 2014
Oslo Interest E. Adli: We got approved a significant amount of money in Oslo for further CLIC/CTF3 work (very good news!), and we plan to work further with design and tests of Wake Field Monitors, and Califes is the natural test-bed. W. Farabolini - CLIC Workshop 2014
Conclusions • CALIFES has proven its value for studying and qualifying the novel accelerating structures, • In addition, CALIFES has gain a growing interest from the beam diagnostic community, • Keeping CALIFES in operation is cost effective, • Simple upgrades will offer even more opportunities to progress in Lepton accelerators Science and Technology. A big thanks to all the colleagues who have contributed with enthusiasm to this presentation by sending me material . W. Farabolini - CLIC Workshop 2014