AVA Projects @ Liverpool Carsten Welsch

The Cockcroft Institute The Opening of the Cockcroft Institute by the Minister of Science, Lord Sainsbury “When we talk about world-class science we need Institute” look no further than the North West and the Cockcroft - Prime Minister, Tony Blair (2006)

CI Beam Diagnostics (examples) Go through all devices briefly and mention methods used and beams, main message – whatever your beam…we can measure it (position, intensity, profiles, emittance) @ CI, CERN, RIKEN, Australian Synchrotron, ESS, CCC, etc. Benefit from lab infrastructure

BLMs@Australian Synchrotron Installation of several prototypes in the AS Two (one) 7 m (5 m) optical fibres with 365 μm (200 μm) SiO2 core: Multi Pixel Photon Counter (MPPC) Photon Multiplier Tube (PMT) Avalanche Photon Diode (APD) Demonstrated time resolution of better than 300 ps – best resolution to date with oBLM system !

Medical Accelerators Aim: Non-destructive measurement of beam tails; Idea: Use LHCb Velo detector to correlate between halo signal and beam current; Study halo – dose relationship. Proof-of-principle: G. Casse, et al., Liverpool

Physics and Biology of Proton Beams Clatterbridge Cancer Centre T. Cybulski, et al., 'A Non-Invasive Beam Monitor for Hadron Therapy Beams‚ Proc. IBIC, Phys. Rev. STAB and Nucl. Instr. Meth. A, in prep.

D-Beam Ltd Commercialization of beam diagnostics www.d-beam.co.uk Optical sensors Beam loss monitors Profile measurement Machine protection www.d-beam.co.uk Established Dec 2015 Presented at IPAC, IBIC, workshops and advertisement campaigns Will apply for CERN BIC

Diagnostics for Beams Based on university R&D Supported by Enterprise Fellowship Benefiting from international links www.d-beam.co.uk

AVA – R&D across all 3 WPs Better facility design New beam handling techniques Online diagnostics Improved detectors Experiments: Novel cooling schemes Spectroscopy on antihydrogen.

Past work: Emittance Measurement Emittance measurements using a scraper Only emittance measurement technique @ ELENA Challenges: Effect of finite dispersion, systematic errors (diffusion, fast scraper) Developing custom codes for realistic simulation – algorithm shall be implemented in future. x x’ Scraper blade moving slowly into beam xs Aβ1/2 xc+Dδ Optimize during ELENA commissioning. J. Resta-López, et al, Nucl. Instr. Meth. A 834 (2016)

AVA – WP1 Beam Stability & Life Time in Low Energy Storage Rings Investigate all effects impacting on beam stability and establish realistic models of beam storage and cooling Develop new simulation tools that enable start-to-end simulations of antiproton pulses through electrostatic low energy beam lines Apply for an overall optimization of beam handling towards the various experiments within AVA.

AVA – WP2: Halo Monitor General definition difficult to make: Accelerator physicists Instrumentation specialists Low density / difficult to measure

Problem Very high intensity in core: Saturates pixels Signal overflow to neighbouring pixels Tail regions are being modified, wrong measurement. Concentrate measurement on tail region ONLY as this is the interesting part ! How ??

SOHO *Solar and Heliospheric Observatory

Halo Monitoring: Core Masking (1) Aquire profile (2) Define core (4) Re-Measure (3) Generate mask C.P. Welsch et al., Proc. SPIE (2007) J. Egberts, et al., JINST 5 P04010 (2010)

Basis: Micro Mirror Array (TI) 1024 x 768 pixels (XGA) USB Interface high-speed port 64-bit @ 120 MHz for data transfer up to 9.600 full array mirror patterns / sec (7.6 Gbs) 16 mm in size +/- 12°tilt angle Switch of 15 ms physically, 2 ms optically

Overview: Imaging System 32mm beam radiation Computer Camera Sensor L3 Mirror RadiationSource L1 DMD L2 L4 Computer Mirror Source Halo Light Core Light DMD Camera Sensor L3 L4 L1 L2 Image 2 Threshold Mask Image 1 Here is sketch of whole system. The source can be intercepted ones like OTR screen, phosphor screen or YAG screen, or non-intercepted one like sychrotron radiation. We first image this 2D transverse beam profile onto the DMD as image 1, and reimage the Image 1 onto the camera sensor as image 2. Image 2 is the one we finally get through the CCD. By change the lenses L3, L4 we can get better resolution. Here is the picture of UMER beam with 21 mA current from phosphor screen. The typical beam core size is 5mm. we use a 16bit, gated, ICCD camera in UMER. We integrated 360 pulses to get the picture near the saturation of the camera. After that, we can choose a threshold level of beam, tell the DMD generate a mask exactly the shape of the beam core, apply it on the image 1 plane. So the corresponding pixels can direct the light from beam core out of the optical system. By integrated more pulses to near the saturation of the CCD, we can get a picture show the halo distribution. In the experiment, We showed this method can have a dynamic range of 10_5. the camera can capture the image by the second focus channel.\ By integration to near camera’s satuation, we can get a beam picture. After that, we apply a mask like this on DMA, the light in the beam core will be switched out of the optical line as showed in the alimation. Finally, by integration more frame, we can set the beam profile near to saturation and get a better view of halo. KILL THE E GUN SOLENOID BEAM, CONCENTRATE ON OPTICS ; SAY BEAM CONDITIONS FOR PICTURE R. Fiorito, H. Zhang, et. al. Proc. BIW10 17

Masking at UMER (10 keV e-) Here is the image using 6mA beam after background substraction, the typical size is 3 mm . First we use our default quadrupole setting for multi-turn beam. Here is the image of the beam. The number in the lower right is the pulses we integrated so that the picture is near the saturtion of the camera, because we want to achieve high dynamic range. After we mask out the beam core, we see two hot spots along the x coordinates outside the beam core. Then we decrease the quadrupole current, introduce large mismatch effects here, we can see that the beam core shape changes but not dramatically. When we apply the threshold mask integrated more pulses of each quadrupole settings. We can find that the halo distribution change dramatically, and both the size and the intensity of halo increased. Look the holes in the mask picture, it shows that our method have a good adaptability when the shape of beam core changes. H. Zhang, et al., Phys. Rev. STAB 15, 072803 (2012)

Measurements at UMER 10 keV e- beam, Phosphor screen iCCD camera Verification of earlier lab measurements Reconstruction of beam profile with DR of 105 Effects from diffraction on DMD are minimal !! H. Zhang, et al., Phys. Rev. STAB 15, 072803 (2012)

Advantages Can be used with any raditiation (OTR, ODR, SR, Smith-Purcell, Cherenkov, etc.); Suitable for any charged particle beam; Advanced measurements possible: XDR, emittance, phase space mapping, injection optimization, etc. Here: Apply for beam imaging

A DMD based Beam Halo and Emittance Monitor Develop towards online, non-destructive beam profile measurements using light generated by the primary beam (p or pbars) In a second step, measurements will be extended towards emittance and general 6D phase space diagnostics 

AVA – WP3: Gas Jet Monitor Setup @ CI; Gas jet, IPM and BIF; Designed for use with low energy pbars: Profile monitor Collision studies. Excellent tool for studies into jet properties. M. Putignano, C.P. Welsch, Nucl. Instr. Meth. A 667 (2012) V. Tzoganis, C.P. Welsch, Apl. Phys. Letters (2014). V. Tzoganis, C.P. Welsch, et al., VACUUM (2014).

Setup @ Cockcroft Institute ^^

Results @ CI Residual gas signal Jet signal e- beam Gas Jet V. Tzoganis, et al., APL 104 204104 (2014) VACUUM (2015)

Understanding the Jet Simulations using the CST and WARP codes Excellent agreement – jet understood in simulations – tool for further optimization Unit(mm) Experiment Simulation sx 0.56 ± 0.02 0.57 sy 0.53 ± 0.03 0.61 sx (residual gas) 1.52 ± 0.07 1.23 H. Zhang, et al., Phys. Rev. AB (2016), submitted

High Luminosity LHC-UK Non-invasive diagnostics for main beam and hollow e- beam Considering different gas jet shaping schemes Nozzle-Skimmer geometry Fresnel Zone plates Analyzing quality in IPM and BIF mode with CERN and GSI Expaning simulation work into jet optimization with CERN and STFC 2nd prototype setup will be installed at the CI in 2017 FZP – with Bergen university, demonstrated already 30 um jet diameter achievable…high density…higher signal levels V. Tzoganis, et al., APL 104 204104 (2014)

AVA – Jet based experiments Identify methods to realize compact (less than 1 mm diameter), ultra-short (1-2 ns duration) antiproton beam pulses as required for investigations into correlated quantum systems Compression will be based on higher harmonic bunching and phase space ‘gymnastics’ and, for the first time, extended to a full 3D description of bunches motion, including all effects on the beam (intra beam scattering, phase space rotation, scattering, cooling) In-ring schemes will be studied, along (quasi) single-pass setups in an external beam line or a dedicated small storage ring.