PETRA III. Machine development Satellite bunch clearing Rainer Wanzenberg DESY - MPE - for the PETRA III team Three Way Meeting, DESY, Hamburg Sep 15, 2016 1

The DESY site in 2016 Extension Hall East Extension Hall North LINAC II  PIA  DESY II  PETRA III C = 29 m, E =450 MeV C = 293 m, E = 6 GeV C = 2304 m, E = 6 GeV Extension Hall East Max von Laue Hall Extension Hall North

PETRA III Implementation of the PETRA III extension: Parameter PETRA III Energy / GeV 6 Circumference /m 2304 Emittance (horz. / vert.) /nm 1.2 / 0.012 Total current / mA 100 Number of bunches 960 40 Bunch population / 1010 0.5 12 Bunch separation / ns 8 192 Damping Wigglers: B ~ 1.5 T, l = 0.2 m 2 x 10 x 4 m = 80 m, ex: 5 nm  1.2 nm Implementation of the PETRA III extension: Feb 2014 – Feb 2015, Two New Halls PXN, PXE

New beam lines: Tentative time line First beam P65 X-ray absorption spectroscopy Oct. 2015 P64 Spring 2016 P24 Chemical crystallography 2Q 2017 P21 High-energy X-ray materials science P22 Nano X-ray spectroscopy P23 Nano X-ray diffraction P66 Time-resolved luminescence spectroscopy t.b.d. P61 High-energy X-ray eng. mat. sci. (HZG) LVP extreme conditions (DESY) 2018 P62 Small-angle X-ray scattering >2018 P63 t.b.c. ----- P25 t.b.c Phase 1 Phase 2 Phase 3 4 4 4 4

PETRA III Extension North New Beam lines P64 and P65 Tue 8.9.15, first photon beams from PU64 and PU65, 1 mA run P 65 First experiments in Oct. 2015 scheduled user from June 2016 P 64 First experiments in May 2016 after a problem with the monochromater was solved

Beam line Set Up P 64 / P 65 (April, 2016) Large fringe field from the PDE dipole compensation for the horizontal kick small residual vert. kick compromise for the photon beams PU64 PDE Dipole 20 mrad PDE dipole: New coil configuration has been ordered installation is planned for the 2016/17 winter shut down kick compensation: A correction coil of the dipole is set according to the undulator gap P65

Satellite bunches Timing mode with 40 Bunches, some experiments need a very good bunch purity (~ 10-9 … 10-8 ) But there are satellite bunches generated in PETRA (2 ns and 4 ns) from the injector chain (125 MHz in PIA) Studies started Aug. 2015: satellite bunch clearing using the Multibunch feed back system Ref.: Longt. bunch structure in the Photon Factory T. Obina et al. NIM A 354 (1995) 204-214 Bunch Purity Measurements at PETRA III J. Keil et al. IPAC 2016 Measurement at beam line P01, July 31, 2015 13:45 h

Satellite bunch clearing Measurement after clearing and 1 h later In timing mode: X-ray pulses with 90ps width and 192ns separation for pump probe & nuclear resonant scattering (NRS) measurements. Suppression down to 10-8 is required MBFB, vert. excitation of the satellite bunches Bunch clearing in 2015 proof of principle satellite bunches can be cleared using the multibunch feedback measurement of the sattelite bunches in close collaboration with beam line P01 procedure and claering parameters not yet optimized

→ powerful broadband feedback neccessary Multi bunch feedback Coupled bunch instabilities in PETRA: longitudinal horizontal vertical Ithres (mA) 7 6 1/t (Hz) 35 50 60 Zeff 3.6 MΩ 45 MΩ/m 54 MΩ/m PETRA III: 12 seven cell cavities which large par. shunt impedance → powerful broadband feedback neccessary Required damping 1/t: Longt. 800 Hz or 1.25 ms Horz. 1400 Hz; Vert. 1400 Hz or 0.7 ms Bandwidth 62.5 MHz (8 ns bunch spacing) Sattelite bunch clearing: Intensity dependent tune shift: ~ 1.6 kHz / mA (vert. Plane) 40 Bunche mode: 2.5 mA bunch current vert. Feedback can excite the low intensity sattelite bunches at their betatron tune J. Klute, K. Balewski et al., DIPAC’11, TUPD81

Sattelite bunches: automatic clearing procedure (2016) satellite bunches measured at beam line P01 generated in PETRA (2 ns and 4 ns) from the injector chain (125 MHz in PIA) User Run 2016: satellite bunch clearing using the Multibunch feed back system, automatic procedure at every n-th top up injection (n = 1, n =100) – 8ns 8 ns red 8 ns, blue – 8ns Timing mode with 40 Bunches, some experiments need a very good bunch purity (~ 10-9… 10-8) measurement cycle ~ 15 min 10-8

Clearing procedure: impact on beam line signals Signal from beam line P10 (counts per second) drop by ~ 25 % is not acceptable for some experiments. further optimization with reduced kick amplitude and sweep range (tune frequency range) User Run 2016: successful satellite bunch clearing using the multi bunch feed back system with neglectable impact for the beam lines automatic procedure at every top up injection was development in close collaboration with the beam lines *), the feedback group, the software group, the Preaccelerators (DESY II, Linac, Pia) zoom signal current *) Beam line P01: O. Leupold, H.-C. Wille

Emittance Diagnostics North: interferometric measurement dipole radiation (originally set up for a bunch length measurement) Von Laue Hall: Diagnostic Beam Line South East: new diagnostic station

Emittance Diagnostics in SE South East: new diagnostic station

PETRA III: Beamlines in hall East – Further plans P 22 Nano spectroscopy P 21 High-energy X-ray materials science P 23 Nano diffraction P 24 Chemical crystallography Front end components for the photon beam lines P 22, 23, 24 have been installed in the East hall during the last shut down 2015/16. Welche Beamlines sind das? Flaggen reinpacken, international: Schwedisch, Indisch, Russisch Beginn Nutzerbetrieb: P64 war sogar schon

Tentative schedule and plans 2017 Shut down 2017 Jan / Feb / March installation of a chicane in the straight section east preparation for the installation of an In Vacuum Undulator survey / realignment of the accelerator components installation of the undulators PU 22, 23 and 24 new coil configuration for PDE magnets Shut down 2017 July / Aug installation of an new absorber in the wiggler section North 2017: installation of a chicane, and front end components front end components installed in 2015/16 2017: installation of undulators, realignment of accelerator components 2017 July: new absorber + front end components installed in 2015

In-vacuum undulators Two in-vacuum undulators PETRA III: 14 Beamlines in the Max von Laue Hall Two in-vacuum undulators (One undulator for P21) have been ordered delivery of the first undulator is scheduled for 2017 Number ID Type Energy range (keV) Cell P01 10 m U32 (2 x 5 m) 5 – 40 P02 2 m U23 20 – 100 1 P03 2 m U29 8 – 25 P04 4 m U65 (APPLE) 0.2 – 3.0 2 P05 8 – 50 3 P06 2 m U32 2.4 – 50 P07 (option low beta) 4 m U19 (IV) (pres. 2m) 50 – 300 4 P08 5.4 – 30 5 P09 P10 5 m U29 4 – 25 6 P11 8 – 35 7 P12 4 - 20 P13 5 – 35 8 P14 5 - 35 another one is foreseen for P07 High bx Low bx High beta: bx = 20 m by = 4 m Low beta : bx = 1.4 m by = 4 m Max von Laue Hall: 14 beam lines 8 DBA cells ( length 23 m)

Thank you for your attention !