Revised Commissioning Strategy Sven Reiche :: SFBD :: Paul Scherrer Institut Revised Commissioning Strategy Commissioning Workshop 2016

Introduction Strategy driven by beam dynamics and FEL objectives Requisite for hardware given by objectives Hard requisites: e.g. X-band operational for Compression Commissioning should stop and allow for installation and repair if no further commissioning objectives can be achieved Soft requisites: e.g. Amplitude laser not available, but Jaguar is. Commissioning can continue but requires to return and repeat this commissioning step once the requisite is fulfilled. Missing soft requisites must be evaluated if it makes sense to continue Example 1: Setting up TDS and measurement procedures with jaguar is useful Example 2: Slice emittance optimization with jaguar is a waste of commissioning time Commissioning should not happen for the sake of filling the commissioning time slot if no further objectives can be fulfilled

Injector I - Gun Goal (Minimal Goal): Demonstrate generation of electron beam Set-up gun phase procedure Hard requisite: Gun RF commissioned, Laser available, Gun spectrometer functional Both screens, a BPM and one charge measurement (WC or ICT) ready in SINEG01 Soft requisite: Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values 200 pC charge

Injector II – Transport, Optics & Proj. Emittance Goal (Minimal Goal): Transport beam to injector spectrometer Achieve 150 MeV beam energy Establish stable beam optics for transport Measure projected emittance of uncompressed beam Hard requisite: SINSB01 and SINSB02 RF commissioned All BPMs, Screens in SINLH01, SINBC01, SINDI01, S10DI01 and S10BD01 All magnets except Bunch Compressor and Laser Heater Soft Requisite: Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values 200 pC charge

Injector III – Slice Emittance, Optimization Goal: Set-up TDS measurement Measure slice emittance and longitudinal phase space Optimize slice emittance and mismatch for uncompressed bunch Hard Requisite: TDS RF commissioned Soft Requisite: Amplitude Laser available Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values except camera S10DI01 and S10BD01 with nominal resolution 200 pC charge

Injector IV – Bunch Compression Goal: Set-up nominal bunch compression Demonstration and optimization of slice emittance values Hard Requisite: BC1 movable and operational All RF stations operational Soft Requisite: Amplitude Laser available Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values except cameras in S10DI01 and S10BD01 200 pC charge

Injector V – Laser Heater Goal: Demonstrate induced energy modulation with laser heater Hard Requisite: LH chicane and undulator operational LH laser pulse available LH diagnostics operational Soft Requisite: Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values 200 pC charge

Injector VI – Stability & Reproducibility Goal: Demonstrate reproducible and stable operation of the injector Commissioning of the beam-based feedback system Hard Requisite: All feedback-related diagnostics available Soft Requisite: Jitter and drift are fulfilling SwissFEL tolerances Diagnostics has nominal resolution 100 Hz operation BS data aquisition

Linac I - Transmission Goal (Minimal Goal): Transport of the beam to the Aramis beam dump Acceleration with C-Band to 500 MeV Hard Requisite: S10CB01 operational BPMs and screens available All magnets operational except BC2 and septum magnet / Resonant kicker Soft Requisite: 200 pC Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values

Linac II – Optics (e.g. Collimator, Switchyard) Goal: Establish nominal beam transport Commissioning energy collimator Hard Requisite Energy collimator operational Soft Requisite BAM in SARBD01 Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values

Linac III – Undulator Alignment Goal: Beam based alignment of QFF magnets Beam based alignment of undulator modules Evaluation of settings for entrance and exit correctors and earth magnetic coil Hard Requisite: All undulator modules operational Soft Requisite: 1.7 GeV beam energy 200 pC Stability in jitter and drift: 5 times the SwissFEL tolerance values Diagnostic resolution: 5 times the SwissFEL design values

Linac IV – Bunch Compression Goal: Bunch compression with BC2 Emittance optimization with two-stage compression Compression set-up Hard Requisite: BC2 operation C-Band TDS operational Soft Requisite: Amplitude laser 200 pC Full Linac 1 energy Stability in jitter and drift: 2 times the SwissFEL tolerance values Diagnostic resolution: 2 times the SwissFEL design values

Linac V – Stability and Reproducibility Goal: Demonstrate reproducible and stable operation of the linac and undulator line Commissioning of the beam-based feedback system Hard Requisite: All feedback-related diagnostics available Soft Requisite: Jitter and drift are fulfilling SwissFEL tolerances Diagnostic has nominal resolution 100 Hz operation BS data aquisition

FEL I – FEL Gain Observation Goal (Minimal Goal): Demonstration of FEL signal on Screen Hard Requirement: Same as Linac III Soft Requisite: Linac IV concluded

FEL II – FEL Characterization Goal: Commissioning of photon diagnostics and optics in front-end and optical hutch Photon beam alignment with spontaneous radiation Measurement of FEL gain curve, photon energy, spectrum and pulse energy Hard Requisite: Front-end and optical hutch hardware operational Beam energy 2.1 GeV Soft Requisite: Beam energy 3 GeV Nominal two-stage bunch compression achieved Amplitude laser 200 pC Stability in jitter and drift: 2 times the SwissFEL tolerance values Diagnostic resolution: 2 times the SwissFEL design values

FEL III – FEL Saturation and Optimization Goal: Achieving photonics milestone at 3 GeV (saturation, pulse energy, stability) Hard Requisite: Full instrumentation of front end and optical hutch Beam energy 3 GeV Soft Requisite: Amplitude laser 200 pC Nominal two-stage bunch compression achieved Stability in jitter and drift: 2 times the SwissFEL tolerance values Diagnostic resolution: 2 times the SwissFEL design values

FEL IV – Operation at 1 A, Stability, Rep Rate Goal: Demonstrate photonics milestone at 1 Angstrom Commissioning of experimental stations End of Commissioning for Aramis at 200 pC Hard Requisite: Full Instrumentation of SwissFEL Machine jitter and drift within SwissFEL tolerances Diagnostics resolution within specification.

Causal Dependence of Commissioning Steps 150 MeV 350 MeV Injector I (Gun) Injector II (Transport) Injector III (Emittance) Injector IV (BC1) Injector V (LH) Injector VI (Stability) 500 MeV 1.7 GeV 2.1 GeV Linac I (Transport) Linac II (Optics) Linac III (Alignment) Linac IV (BC2) Linac V (Stability) 2.1 GeV FEL I (Demonstr.) Minimal Goal Milestones Twice relaxed nominal stability 3.0 GeV 5.8 GeV FEL II (Charact.) FEL III (Optimiz.) FEL IV (Stability) Nominal stability

Time Line (Ideal, Soft Requisites Fulfilled) PIC plan slot for injector PIC plan slot for injector, linac, undulator and front end PIC plan slot for full machine, including end stations Relaxed Stability (x2) Much Relaxed Stability (x5) Nominal Stability 2.1 GeV @ BC2 4.7 GeV 150 MeV 350 MeV 540 MeV 2.7 GeV 5.8 GeV 2016 2017 Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Inj I-III Inj IV Lin I+II Inj V Lin III Fel I Lin IV Fel II+III Inj VI Lin V Missing: Fel IV: 28 weeks (15 weeks for 1st user station) 10 pC Mode Large Bandwidth Mode Switchyard and Athos Two Bunch Operation During User Operation ~1 week per month