Feedback On Nanosecond Timescales (FONT): Robert Apsimon, Philip Burrows, Neven Blaskovic, Douglas Bett, Glenn Christian, Michael Davis, Davide Gamba, Alexander Gerbershagen, Young Im Kim, Colin Perry, Jack Roberts John Adams Institute Oxford University Beam feedback and phase FF 1

Oxford k-contract WP1: design of FB and control systems staff months + £58k WP2: design of FF systems staff months + £165k WP3: design of laserwire systems staff months + £21k Total: staff months + £244k Key:UK, CERN 2

WP3: design of laserwire Laser Wire Scanner for Profile Measurements on the CLIC Drive Beam - PETRA Exploitation of LWS facility at PETRA 3 in DESY Design a laser wire scanner system adapted to the Drive Beam requirement (2.4GeV, 20um resolution) Implement an electro-optically driven fast scanning system by shipping out a mode-locked laser system from RHUL to DESY and validate the concept of fast scanning for Drive Beam trains as long as 140us Laser Wire Scanner for Profile Measurements on the CLIC Main Beam – ATF2 Exploitation of LWS facility at ATF2: Use nearby BPM and subtract beam position jitter form the LWS scans Design of the CLIC MB Laser Wire at different beam energies along the complex (2.4GeV, 9GeV, 1.5TeV) - Study the different detection scheme and laser system implications Fibre laser developments for cost reduction and implementation in CLIC infrastructure In close relation with industry, follow and test the performance of fibre lasers in term of beam quality and laser power. Test of high power fibre laser in the accelerator environment (ATF2) Define the implementation of laser system for LWS in CLIC Complex (Drive beam and Main beam) 3

WP1: FB and control Simulation, design and prototyping of IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation at CLIC. Integration of components within Machine Detector Interface (MDI) design. Completion of the ATF2 prototype systems as part of the ATF2 collaboration goals of 37nm beam size and nm- level beam stabilisation. Bench testing of relevant components for CLIC prototypes, and exploration of the possibility of beam tests of prototype components at CTF3. Provision of feedback system parameters for modeling the integrated performance of feedback and feed-forward systems in the global CLIC design. 4

WP1: FB and control Simulation, design and prototyping of IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation at CLIC. Integration of components within Machine Detector Interface (MDI) design. Completion of the ATF2 prototype systems as part of the ATF2 collaboration goals of 37nm beam size and nm- level beam stabilisation. Bench testing of relevant components for CLIC prototypes, and exploration of the possibility of beam tests of prototype components at CTF3. Provision of feedback system parameters for modeling the integrated performance of feedback and feed-forward systems in the global CLIC design. 5

WP1: FB and control Simulation, design and prototyping of IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation at CLIC. Integration of components within Machine Detector Interface (MDI) design. Completion of the ATF2 prototype systems as part of the ATF2 collaboration goals of 37nm beam size and nm- level beam stabilisation. Bench testing of relevant components for CLIC prototypes, and exploration of the possibility of beam tests of prototype components at CTF3. Provision of feedback system parameters for modeling the integrated performance of feedback and feed-forward systems in the global CLIC design. 6

CLIC Final Doublet Region 7

8

9

WP1: FB and control Simulation, design and prototyping of IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation at CLIC. Integration of components within Machine Detector Interface (MDI) design. Completion of the ATF2 prototype systems as part of the ATF2 collaboration goals of 37nm beam size and nm- level beam stabilisation. Bench testing of relevant components for CLIC prototypes, and exploration of the possibility of beam tests of prototype components at CTF3. Provision of feedback system parameters for modeling the integrated performance of feedback and feed-forward systems in the global CLIC design. 10

CLIC IP FB model 11

CLIC IP FB performance Single random seed of ground motion (Model C): beam tracked through whole CLIC complex 12 Many seeds of ground motion, and Models A, B, C, K:

IP FB documented in CDR 3.6 Machine-Detector Interface (p. 167) 3.8 Integrated simulations on low-emittance preservation (p. 191) 5.12 Machine-Detector Interface (p. 552) 5.15 Real-time feedback equipment (p. 583) 13

WP1: FB and control Simulation, design and prototyping of IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation at CLIC. Integration of components within Machine Detector Interface (MDI) design. Completion of the ATF2 prototype systems as part of the ATF2 collaboration goals of 37nm beam size and nm- level beam stabilisation. Bench testing of relevant components for CLIC prototypes, and exploration of the possibility of beam tests of prototype components at CTF3. Provision of feedback system parameters for modeling the integrated performance of feedback and feed-forward systems in the global CLIC design. 14

FONT5 installation at ATF2 ATF2 extraction line 15

FONT5 operation at ATF2 16 Aim to stabilise beam in IP region using 2-bunch spill: 1. Upstream FB: monitor beam at IP 2. Feed-forward from upstream BPMs  IP kicker 3. Local IP FB using IPBPM signal and IP kicker 16

Upstream FONT5 System Analogue Front-end BPM processor FPGA-based digital processor Kicker drive amplifier Stripline BPM with mover system Strip-line kicker Beam BPM Resolution < 350nm Dynamic range of the BPM system+/-500μm System Latency<150 ns Amplifier Bandwidth~30 MHz 17

Interaction Point FONT System Analogue Front-end BPM processor FPGA-based digital processor Kicker drive amplifier Strip-line kicker Designed in house 12.5 cm stripline kicker Based on ATF stripline BPMs Beam Cavity BPM 18

ATF2 beam stabilisation results 1.Upstream FB: beam stabilised at IP to ~ 300 nm 2. Feed-forward: beam stabilised at IP to ~ 106 nm 3. IP FB: beam stabilised at IP to ~ 93 nm Getting interesting! (i.e. hard) 19

Upstream FB (Measured at IPB) FB Off Jitter: 0.35 ± 0.02 μm FB On Jitter: 0.30 ± 0.01 μm FB Off Correlation: 79% FB On Correlation: 14% 20

Feedforward Results FF Off Jitter: 160 ± 10 nm FF On Jitter: 106 ± 10 nm FF Off Correlation: 73% FF On Correlation: 23% 21

IP Feedback Results FB Off Jitter: 170 ± 10 nm FB On Jitter: 93 ± 4 nm FB Off Correlation: 81% FB On Correlation: -16% 22

WP1: FB and control Simulation, design and prototyping of IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation at CLIC. Integration of components within Machine Detector Interface (MDI) design. Completion of the ATF2 prototype systems as part of the ATF2 collaboration goals of 37nm beam size and nm- level beam stabilisation. Bench testing of relevant components for CLIC prototypes, and exploration of the possibility of beam tests of prototype components at CTF3. Provision of feedback system parameters for modeling the integrated performance of feedback and feed-forward systems in the global CLIC design. 23

Future work proposal Optimisation of the performance of ATF2 feedback systems as part of the ATF2 collaboration goals of 37nm beam size and nm-level beam stabilisation. Optimised design of CLIC IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation. Integration of component designs within Machine Detector Interface (MDI) design. Where relevant, bench testing of prototypes: drive amplifiers, signal processors, feedback boards. Beam tests of prototype systems at ATF2 and CTF3. With task 2.1: simulation of the integrated performance of feedback (and feed-forward) systems in the global CLIC design. 24

Future work proposal (1) Optimisation of the performance of ATF2 feedback systems as part of the ATF2 collaboration goals of 37nm beam size and nm-level beam stabilisation: Tuning shifts at ATF2 (tuning tools – Rogelio et al) Commission new IP chamber (with LAL, KNU, KEK) Understand new C-band cavity BPMs + signal processors Implement new BPMs into IP FB loop Push beam stabilisation 100nm  10nm (  1nm??) 25

Future work proposal (2) Optimised design of CLIC IP (and interface with related BDS) beam steering feedback systems for luminosity stabilisation and optimisation. Integration of component designs within Machine Detector Interface (MDI) design. More realistically-engineered design: Radiation hardness of electronics (evaluation of backgrounds) Cabling + shielding RF interference Larger L* would require a complete re-design 26

Future work proposal (3) Where relevant, bench testing of prototypes: drive amplifiers, signal processors, feedback boards. Beam tests of prototype systems at ATF2 and CTF3. With task 2.1: simulation of the integrated performance of feedback (and feed-forward) systems in the global CLIC design. 27

Future proposed FB resources Faculty: Burrows, Christian Electronic engineer: Perry Postdoc: Vice Bett (working jointly on phase feed-forward) Existing student: Blaskovic New student:TBD 28

WP2: drive beam phase FF Simulation, design and prototyping of components for feed- forward systems for correcting phase instabilities in the CLIC drive beam. Integration of components within CLIC drive beam design. Liaison and coordination with collaborators working on related systems, in particular the phase monitors and kickers. Development and bench testing of relevant prototypes and components, in particular for the high-power kicker drive amplifiers. Study for possible beam tests of prototypes at CTF3. 29

WP2: drive beam phase FF Simulation, design and prototyping of components for feed- forward systems for correcting phase instabilities in the CLIC drive beam. Integration of components within CLIC drive beam design. Liaison and coordination with collaborators working on related systems, in particular the phase monitors and kickers. Development and bench testing of relevant prototypes and components, in particular for the high-power kicker drive amplifiers. Study for possible beam tests of prototypes at CTF3. 30

WP2: drive beam phase FF Simulation, design and prototyping of components for feed- forward systems for correcting phase instabilities in the CLIC drive beam. Integration of components within CLIC drive beam design. Liaison and coordination with collaborators working on related systems, in particular the phase monitors and kickers. Development and bench testing of relevant prototypes and components, in particular for the high-power kicker drive amplifiers. Study for possible beam tests of prototypes at CTF3. 31

Phase FF documented in CDR 4.3 Beam transport (p. 250) 5.15 Real-time feedback equipment (p. 585) 32

WP2: drive beam phase FF Simulation, design and prototyping of components for feed- forward systems for correcting phase instabilities in the CLIC drive beam. Integration of components within CLIC drive beam design. Liaison and coordination with collaborators working on related systems, in particular the phase monitors and kickers. Development and bench testing of relevant prototypes and components, in particular for the high-power kicker drive amplifiers. Study for possible beam tests of prototypes at CTF3. 33

WP2: drive beam phase FF Simulation, design and prototyping of components for feed- forward systems for correcting phase instabilities in the CLIC drive beam. Integration of components within CLIC drive beam design. Liaison and coordination with collaborators working on related systems, in particular the phase monitors and kickers. Development and bench testing of relevant prototypes and components, in particular for the high-power kicker drive amplifiers. Study for possible beam tests of prototypes at CTF3. 34

WP2: drive beam phase FF Simulation, design and prototyping of components for feed- forward systems for correcting phase instabilities in the CLIC drive beam. Integration of components within CLIC drive beam design. Liaison and coordination with collaborators working on related systems, in particular the phase monitors and kickers. Development and bench testing of relevant prototypes and components, in particular for the high-power kicker drive amplifiers. Study for possible beam tests of prototypes at CTF3. 35

Future work proposal Develop feedback boards and amplifiers for CTF3 phase feed-forward prototype system. Commission CTF3 prototype feed-forward system with beam. With beam experience, optimise component design and test modified components. Apply experience gained from CTF3 prototype to CLIC drive beam design, including performance simulations. 36

Future proposed FF resources Faculty: Burrows, Christian Electronic engineer: Perry Postdoc: Vice Bett (working jointly on beam feed-back) Existing students: Roberts, Gamba New student:TBD 37

Oxford resources (1/4/11-31/3/14) Oxford-k CERN-k actual Staff effort (months): Burrows, Christian 54 Christian, Kim, Bett, Corner, Nevay 73 Perry 36 PhD students (months): Apsimon, Bett, Davis, Blaskovic102 Gerbershagen, Roberts, Gamba 57 Materials + travel (k£):