The European XFEL: Commissioning of the Electron Accelerator Presented at the Radsynch 2017 Workshop at NSRRC, Taiwan April 19-22, 2017 Albrecht Leuschner, Norbert Tesch, Wolfgang Clement: DESY Hamburg
Radiation Safety at the European XFEL Intro: The XFEL Some specifications • Length 3.4 km • Superconducting linac max. 20 GeV • Max. beam power 1.2 MW • Max. beam power per dump 0.3 MW Max. particles 10 14 electrons/s • • Rep.Rate 10 Hz (2700 bunches) • Photon energy 0.3 - 24 keV • Pulse duration ~ 10 - 100 fs • Pulse energy few mJ • 5 beamlines / 10 instruments • Start version with 3 beamlines SASE2 and 6 instruments 0.15 – 0.4 nm • Start of construction begin 2009 • Start of operation begin 2017 SASE1 0.05 – 0.2 nm SASE3 0.4 – 1.7 nm Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The XFEL Photon beamline tunnels Accelerator tunnel Schenefeld: • Research with photons • Center of the international research facility Undulator tunnels Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: Challenges 96 accelerator modules 768 accelerating cavities 1.3 GHz / 23.6 MV/m i r f u i r f u i r f u s s s a a a c c c l l l a a a y y y Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Injector Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Main Linac Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Main Linac Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Main Linac Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Beam Dumps Beam dumps will be installed here: • 2 (1 for the beginning) injector dump(s) • 1 BC1 (bunch compressor) dump • 1 BC2 (bunch compressor) dump • 1 main dump at XS1 • 2 main dumps at XSDU1 and XSDU2 Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Beam Dumps Number and Typ 3x MAIN 1x BC 2 1x BC 1 2x INJ XSDU1/2 : end e-beams BC2 BC1 Injector Purpose XS1 : Linac Tuning Tuning Tuning Tuning C core, Cu shell Al core, Cu shell Construction (see below) With beam window Without beam window Limits of operation ≤ 25GeV ≤ 2.5GeV ≤ 500MeV ≤ 300MeV E 0 , beam energy ≤ 4000nC (total) ≤ 40nC ≤ 4000nC q t , charge in bunch train ≤ 40 µ A ≤ 4 µ A ≤ 0.4 µ A ≤ 40 µ A I ave , average current ≤ 300kW (per dump) ≤ 10kW 1) ≤ 200W ≤ 12kW P ave , ave. beam power Beam properties σ x,y , size @ dump ≥ 2mm ≥ 3-4mm ≥ 0.2mm ≥ 2-3mm Slow Sweep Yes with R s = 5cm No Fast (intra train) Sweep No if minimum size is guarenteed 1) Thermal limit, radiation protection limit is 500W Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Experiments Talks by Eric Boyd and Michael Dressel in later sessions Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The Time Table Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Accelerator: Measurements / LB 6419 Measurement of ambient dose equivalent: Gammas and neutrons Pulsed and continuous radiation Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Accelerator: Air Activation / Ventilation Scheme RLT = ventilation system Concept of ventilation = outside air • 3 inputs: fresh air input = processed outside air = exhaust air only at 3 shafts • 1 output: push all air from hot regions (dumps) through the whole tunnel • With this concept the planning goal of using only 10% of the legal limit can be reached (FLUKA simulations folded with ventilation concept) • In addition there will be 12 air monitoring systems distributed over the whole facility Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Air Activation by electron energy mismatch Measured net activity concentration in the exhaust shaft: 500 Bq/m 3 mainly 13 N (10 min) and 2 GeV x 0.5 nC x 30 bunches x 10 Hz = 0.3 kW 11 C (20 min) Delay by air flow : 6 ½ min 5 h β counter with a thin wall BC 2 beam dump line 420 µSv/h 280 µSv/h Residual dose rates on surface after 1 ½ days cooldown 1100 µSv/h Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Dark Current from Cryo-Modules Experiment on dark current is planned. FLUKA model is adopted to the EuXFEL by Mario Santana Leitner, SLAC Goals: • Gain insights about field emission and dark current transport at XFEL • Verify field emission radiation for 3 rd CM of L3 installed in Linac • Verify if BLMs are adequately set to detect radiation • Evaluate applicability of SLAC field emission simulations to DESY LB 6419 : Photon and Neutron Dose Rate Monitor for Accelerators (Continuous and pulsed radiation) ICALEPCS2017 Conference in October 2017 “ MARWIN : A Mobile Autonomous Robot for Maintenance and Inspection” Andre Dehne, Nantwin Möller, Thorsten Hermes, hochschule21 gGmbH, Harburger Strasse 6, 21614 Buxtehude, Germany Reinhard Bacher, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Cockpit Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Accelerator Commissioning Status on April 13 th North Branch: Personnel Interlock System tested, beam onto main dump expected next week. Accelerator: April 9 th electron beam onto main dump 0.5 nC x 30 bunches x 10 Hz @ 12 GeV South Branch: Commissioning Sommer 2017 Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL The End. Thanks for Attention ! Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Intro: The XFEL and Money Remark: All numbers above are given in “2005 Euro”, total sum will be about 1,5 Billion Euro in “2015 Euro” Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Accelerator: AMTF and Warm Conditioning AMTF = “Accelerator Module Test Facility” to test cavities and modules for XFEL Requirement: Conditioning of RF power couplers in warm accelerator modules with access to the tunnel @ AMTF and XFEL (operate and work at the same time!) • Modules must be warm (T>200 K)! • RF cannot generate dark current on cold resonance frequency • Safety signal: temperature threshold • RF not on warm resonance frequency! • Narrow RF band filters in RF drive of klystron (LLRF controls) • Safety signal: contact of filter position Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Accelerator: Radiation Protection Calculations Most of the calculations to verify the protection of the public had been carried out with the FLUKA program tools, as there are the following topics: • Direct radiation from warm sections • Direct radiation from beam dump sections • Direct radiation due to muons • Activation of soil • Activation of ground water • Activation of tunnel air All these calculation showed that we are well below our planning goal of using not more than 10% of the legal dose limits for protection of the public A second set of calculations had been done to check the internal radiation level at critical locations, as there are the following topics: • Direct radiation from the beam dump sections in the shafts • Activation of beam dump and collimator components (to design beam dumps) • Air activation inside the beam dump cavern • Activation of cooling water • Activation of concrete (to select optimal mixture already at construction phase) Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Accelerator: Interlock Concepts Requirement: Access should Interlock be possible to each photon Areas tunnel while other photon tunnel(s) are in operation Warning Areas For details see talk of B. Racky / Radsynch 2013 Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
Radiation Safety at the European XFEL Accelerator: Interlock Concepts RF distribution and interlock Controlled access and interlock Radsynch 2017 - April 19, 2017 - Albrecht Leuschner, DESY
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