SPS Beam Synchrotron Radiation monitor SPS transverse beam
SPS Beam Synchrotron Radiation monitor SPS transverse beam size diagnostics review 09/11/2015
LHC MD 1900: Measuring the beam halo population via SR Coronagraph G. Trad, D. Mirarchi, J. Barros, E. Bravin, S. Redaelli Merit: Commissioning of the Coronagraph demonstrator installed on B 2. Description: In EYETS a Coronagraph system was installed on B 2 sharing the same optical table of the BSRT. The Coronagraph uses the emitted SR for a non-invasive beam halo measurement. The demonstrator system aims for a contrast ranging from 1 e-3 to 1 e-4. Operational experience is crucial for the Coronagraph final design aiming for the contrast of 1 e-6 needed for Hi. Lumi LHC. The requested MD aims to validate the system alignment and the characterization of the optical diffraction along the coronagraph stages. At Injection, "Halo" will be simulated by blowing Up few bunches and preserving some to act as the "core". Primary collimators will be used to scrape the blown up bunches while simultaneously images will be recorded from the coronagraph. The post processing will probe the capabilities of the instrument to correlate the losses with measured halo. 2 LSWG 08/11/2016
3 LSWG 08/11/2016
Coronagraph Configuration Optical Configuration width Entrance Slit Aperture 19. 9 mm Entrance Slit Centre Occulting Mask Lyot Stop Aperture Lyot Stop Centre 4 19. 7 mm Horizontal Vertical -500 μm -1. 5 mm Position (x, y, s) Diameter (26. 1 K, 43. 3 K, 4 K) 350 μm width Height 5. 2 mm 3. 8 mm Horizontal Vertical -2. 4 mm -1. 85 mm Long. Position Camera Height 0 Analysis of the Magnification q 1 st Stage: • Analytical Calculation (singlet lens) Energy: 450 Ge. V SR source: Undulator Distance_Source_to_Lens: ~28. 5 m 1 st Lens_Focal: ~2 m Mag_1=0. 0755; q 2 nd 3 rd 4 th Stage MAG: • Using the Occulting Mask Fitting a Circle to the mask in the halo images and knowing its real diameter, Þ Mag_2_3_4=(312 px*5. 86μm)/350μm = 5. 22 q Total Magnification MAG=Mag_1*Mag_2_3_4 =0. 394 LSWG 08/11/2016
Experiment A Coll. Gap Intensity Emittances 5 LSWG 08/11/2016
Experiment A 6 LSWG 08/11/2016
REF Experiment A 7 LSWG 08/11/2016
Experiment A Reference image is before scraping start 8 LSWG 08/11/2016
Experiment A Reference image is reset at each step of scraping 9 LSWG 08/11/2016
Experiment A 5. 7090 e+04 prot/grey level Linear Correlation between the lost SR and the scraped halo! 1 0 LSWG 08/11/2016
Conclusions: q Successful MD! q To be repeated varying the coronagraph configuration to probe the system’s sensitivity and maximum measureable contrast 1 1 LSWG 08/11/2016
- Slides: 11