BERLinPro An ERL Demonstration facility at the HELMHOLTZ ZENTRUM BERLIN

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 2 Main components: 100MeV, 100mA beam Small emittance, rel. short bunches High current: to address needs of storage ring users Show energy recovery Explore limits of ERL (multiturn, injection energy) Show different operational modes: high current (100mA, 2ps), short pulses (10mA, 100fs), ??, => superiority of the ERL concept to storage rings BERLinPro: ERL demonstration facility to prepare the ground for a few GeV Berlin-Adlershof Goal: SC-RF gun Booster module – Cornell development with minor modifications Merger: C-chicane, 4 rectangular dipoles Linac: based on Tesla technology, modified for high current Return arc: TBA Second loop option

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 3 Finances and time table : ‚go ahead‘ for gun development R&D money for gun development secured Further approval process for entire budget 2010 beam from 1.6 cell gun cavity in HoBiCaT Conceptual design 2011 Technical layout (TDR) 5 years after approval: first recirculated electrons

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 4 GUN DEVELOPMENT SRF Gun Return Arc Merger Section Main Linac SRF Module Spent Beam Beam Dump SRF Booster 1.5 MeV 5-10 MeV 100 MeV Beam Manipulation Undulator tests

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 5 BERLinPro gun: Staged approach A high brightness source which can deliver high average current and short pulses. Stage 1-Beam Dynamics: Produce beam with cold gun in existing HoBiCaT cryomodule. Nb cavity with Pb-coated cathode (J. Sekutowicz & Co), UV laser (MBI), sc solenoid and beam diagnostics. Stage 2-Cathode integration: Extend HoBiCaT bunker, new cryomodule, cathode preparation infrastructure. Produce 1 to 10 mA with CsK 2 Sb cathode, green laser (MBI). In parallel, test gun cavities and new RF coupler (>100kW) in HoBiCaT. Stage 3-High current operation: Build SRF gun for BERLinPro (high rep. rate) From J. Sekutowicz, Proc. of PAC09 Courtesy of Thorsten Kamps

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 6 Stage 1 setup in HoBiCaT 1.6 cell cavity, sc-solenoid, Helium supply Stage 1 diagnostic beam line View screens, stripline, current monitor, emittance measurement, energy measurement

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 7 HoBiCat preparations:

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 8 MERGER DESIGN CONSIDERATIONS SRF Gun Return Arc Merger Section Main Linac SRF Module Spent Beam Beam Dump SRF Booster 1.5 MeV 5-10 MeV 100 MeV Beam Manipulation Undulator tests

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 9 Zigzag chicane: (Brookhaven) Space charge forces: compatible with emittance compensation scheme Higher order dispersion: intrinsically cancelled by C-chicane with rectangular magnets equal focussing in both planes 2. order dispersion not 0 Small trajectory displacement Fixed relation D1/D2 „Geometrically challenging“ (vertical construction in Brookhaven) Easier to incorporate in machine Flexible drift lengths Offset adjustable by drift length Vertical focussing C-chicane:

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 10 ASTRA: Emittance for Zigzag / C- chicane for increasing bunch charge and different energy spread (correlated) C-chicane Zigzag Gaussian bunch:  x,y = 1.0  mrad  x,y = 1.0 mm  z = 1.0 mm  x,y = 20.0 m  x,y = 0

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 11 Bunch lengthening in merger due to energy spread / space charge Effect is reduced when going to 10 MeV injection energy.

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 12 Emittance vrs. bunch length Gaussian bunch: E = 10 MeV  x,y = 1.0  mrad  x,y = 1.0 mm  x,y = 20.0 m  x,y = 0  E = 20keV Emittance depends strongly on bunch length: Charge  zCompression 77pC6ps3 or more 10pC1ps10 or more 77pC 10pC

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 13 Lambertson magnet: Good idea?? Last merger dipole deflects high energy beam by up to 4° => extra chicane necessary Lambertson: High energy beam travels in field free region, injected low energy beam runs parallel Lambertson would reduce 4° to less than 0.14°, which is rather an orbit correction By Lars-Johan Lindgren, MAX-lab

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 14 L1 d  d \ L20.4m0.8m1.2m 10mm mm mm  [°] as a function of d, L rad = 1.432deg. High energy beam deflected by 1/10: 0.14° mean 2.5cm offset after 10m linac  Steering for HE beam is necessary  Place for HE optical elements before Lambertson Steerer Last merger dipole Lambertson?

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 15 Linac: SRF Gun Return Arc Merger Section Main Linac SRF Module Spent Beam Beam Dump SRF Booster 1.5 MeV 5-10 MeV 100 MeV Beam Manipulation Undulator tests

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN MeV Linac: 1.3 GHz Start with multicell TESLA and adapt this for CW and high current Single cryomodule with 6-7 cavities 7 cells/cavity (?) Application „Verbundforschungsantrag“: federal funding for a collaboration with Univ. Rostock and Dortmund for the calculation of HOM Options for HOMs: Ferrite loads, waveguide dampers HoBiCaT test

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 17 RECIRCULATOR - ARC SRF Gun Return Arc Merger Section Main Linac SRF Module Spent Beam Beam Dump SRF Booster 1.5 MeV 5-10 MeV 100 MeV Beam Manipulation Undulator tests

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 18 Path length management: Short bunches require pathlength adjustment Second loop option: 100MeV: 1. turn: L=(n+1/2) rf 200MeV: 1. turn: L= n rf ( rf /2=12cm) Variable injection energy alters path length in merger & splitter for HE beam 20 o 5-20MeV = MeV => 0.5cm t E E = E 0 cos (  t +  0 ) X   =  – 2  0   =  head with higher E  gives compression with “normal” arc R 56 chirp at deceleration doubles  inacceptable energy spread  L = 2    rf =2-3cm    deg. Courtesy of Michael Abo-Bakr

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 19 3 Approaches to pathlength adjustment: 1 - Brookhaven: Build arc on sledge, mechanical adjustment very precise expensive slow 2 - C-chicane 100MeV: 2-3m CSR – bunches are short 3 - Incorporate into the arc 11 00 00 11 KK SBSB X0X0 X1X1 D0D0 D  1, 3 [ °]  2 [° ]  K [°]  x max /c m Angle and offset for 6cm additional pathlength Courtesy of Michael Abo-Bakr

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 20 Radiation safety requirements: Different ‚league‘ than storage rings Drive costs =>drive beamloss requirements Permissable beamloss:<1e-5? => Too little space for shielding above ground => Consider construction underground reduced shielding, vibrations and temperature fluctuations at comparable costs

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 21 BESSY II Cryogenic plant

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 22

March, 1st, 2010, Bettina Kuske, FLS 2010, SLAC, USA BERLinPro: An ERL demonstration facility at the HELMHOLTZ ZENTRUM BERLIN 23 Building: All dimensions preliminary 55m6.4m 6.0m 15m Storage Ring Hall