WIR SCHAFFEN WISSEN HEUTE FR MORGEN Sven Reiche

WIR SCHAFFEN WISSEN – HEUTE FÜR MORGEN Sven Reiche : : SFBD : : Paul Scherrer Institut Report on SFBD Activities AC Section Meeting, Summer 2016

Publications Title: Two-color beam generation based on wakefield excitation Authors: S. Bettoni, E. Prat, and S. Reiche Journal: Phys. Rev. Accel. Beams 19, 050702 (2016) Title: Undulator beamline optimization with integrated chicanes for X-ray freeelectron-laser facilities Authors: Eduard Prat, Marco Calvi, Romain Ganter, Sven Reiche, Thomas Schietinger, and Thomas Schmidt Journal: J. Synchrotron Radiat. 23, 861 -868 (2016). Title: Two-color operation of a free-electron laser with a tilted beam Authors: Sven Reiche and Eduard Prat Journal: J. Synchrotron Radiat. 23, 869 -873 (2016). Title: Generation of ultra-large-bandwidth X-ray free-electron-laser pulses with a transverse-gradient undulator Authors: Eduard Prat, Marco Calvi, and Sven Reiche Journal: J. Synchrotron Radiat. 23, 874 -879 (2016).

THz facility Requests Facility to generate THz radiation (CERN and PSI) q l = 15 -300 um q E = 10 -100 u. J q Dw/w<10 % q Q = 1 n. C q e <5 um Stacking Wakefield-based LONGITUDINAL TRANSVERSE I~50 A e<2 um

Dechirper design finalization Injector q Defined the geometries defined for several purposes: q Dechirper q 2 -color q linearizer for the injector and the switchyard q Meetings with AMI and Radia. Beam 1. l < 1. 5 mm: dechirper 2. 3. l = 6 mm: linearizer l < 1. 5 mm: two-color Linearizer Dechirper q Geometry ok q Effectivity along the machine q CST tolerance studies (F. Marcellini) p (mm) 0. 50 g (mm) 0. 25 d (mm) 0. 50 a (mm) 1. 25 l (mm) L (m) p (mm) 2. 0 g (mm) 1. 5 d (mm) 1. 5 a (mm) 1. 5 2. 5 q 2 m length ok for the 200 p. C case l (mm) 5. 8 1+1 q Geometry ok L (m) 1+1 To be installed in the injector to test the dechirper:

New optics for ACHIP experiment @ Swiss. FEL Experimental locations: • Switchyard (until 2019): chamber is placed at dechirper’s location / measurement in energy collimator • After Athos undulators (from 2019): measurement after the beam dump Constraints: • Focusing. Along the 1 mm structure: βx ≤ 0. 01 m, βy ≤ 0. 25 m • Measurement. At the profile monitor: minimize β/D 2 • Use Swiss. FEL lattice and two quadrupole triplets at the structure RESULTS @ structure @ profile monitor Switchyard β = 0. 010 m (x) / 0. 018 m (y) σ = 0. 26 µm (x) / 0. 36 µm (x) β = 2. 89 m / D = -0. 33 m Meas. Resolution = 41 ke. V After Athos β = 0. 010 m (x) / 0. 226 m (y) σ = 0. 26 µm (x) / 1. 24 µm (x) β = 0. 01 m / D = -0. 13 m Meas. Resolution = 6 ke. V Optics (switchyard) s (m) Permanent quadrupoles: L=0. 1 m QUADP 1. K 1: -25. 886 m-2 QUADP 2. K 1: 38. 733 m-2 QUADP 3. K 1: -25. 886 m-2 Required field accuracy: 2 e-3 (size is not increased by more than 10 %) Beam at the structure (switchyard)

Participation in the commissioning of the Slice emittance for 500 p. C EXFEL injector • What was done during my stay (May 17 -27): • Projected emittance optimization: 1 µm (x&y) • Laser heater commissioning: screens for transverse overlap • Test/commissioning of orbit and dispersion correction tool • First operation and commissioning of TD: RMS bunch length is about 5. 5 ps • Commissioned slice emittance measurements. Measurements for 500 p. C w/o optimization: values around ~500 nm in the bunch core (specifications: 1 um @ injector, 1. 4 um @ undulator) • Measurement of bunch length and slice emittance with dispersion method. Reconstructed RMS bunch length is around 7 ps. Slice emittance measurement done but not analyzed. Ø Next steps: • Optimization of emittance for different charges • Full commissioning of laser heater Page 6

Self-Seeding /Angel Energy Study at C 1 (CHESS). Areal Detector Side view 1 st Si(531) CC 2 nd Si(531) CC Areal Detector Si(220) Monochromator Resolution 3 x 3 mm 2 FBD & T Thickness under study: Energy: C(400) Si (531) 10 x 10 mm 2 Two Scans: Both directions: • 500 mm • 9 ke. V. • Bragg Scans • Bragg. • 300 mm • 10 ke. V. • Laue Scans. • Forward. • 12 ke. V. Bragg diffraction An Andor C-MOS areal camera was mounted in the detector arm and used to record the forward Bragg and Bragg diffracted beams. Transmission 10 ke. V Seite 7

Self-Seeding /Angel Optical laser 800 nm- 50 fs Test experiment Focusing at FEL (Micro. XAS). M. Harmand et al. NATURE PHOTONICS 7 (2013) 215 KB-Mirrors BD Detector BD ph. SASE 2 nd echo 1 st echo Si 3 N 4 film T XFEL 10 ke. V 80 fs C(220) Wd = 1. 186 Precision Blade 10 -5 d(220) = 1. 26 Å Dx 1 Dx 2 Proposal accepted and experiment taking place this fall. Side view Camera Collaboration with EXFEL for the simulation of photon beam in a crystal. Laue Seite 8

• Pre-beam checks - All injector magnets checked and OK (except gun quads: not accessible + some missing labels) - Next step: diagnostics and vacuum • Controls infrastructure - Launcher, Archiver, Alarm handler running - Config files in preparation - File systems: groups, access list, file structure (afs/nfs) in place • High level applications - Some python applications (BPM overview, Energy manager) already running on VA, need some real channels to test… - First pshell scripts in preparation (gun alignment) - New version of camtool (background subtraction, EPICS interface…) to be released this week

Towards Swiss. FEL Commissioning (Sven) • Online Model-Version 2 - More modular approach(Core, Tracking, Machine-Interface) • Layout 9. 0. 1 released - Mostly «ACHIP» and Athos 2 layout. • HHG –Simulation for Athos (HHG @ 4 nm 1 nm) Seed at 4 nm End of Stage 1 End of Stage 2 @ 1 nm Page 10

Group Activity • Kanu Trip on the Reuss from Bremgarten to Gebensdorf: - One Person per boat: 99 CHF - Two persons per boat: 159 CHF - Three persons per boat: 199 CHF http: //www. daily-adventure. ch/de • Please fill out the Doodle (for those who haven’t yet) to find the date: http: //doodle. com/poll/736 rgzip 8 ttqgqtn Page 11