Design inputs for an improved BWS sensoracquisition system

Design inputs for an improved BWS sensor/acquisition system Future acquisition system meeting 31. 10. 2017 J. Emery

Design inputs for an improved BWS sensor/acquisition system • 2018 Last run before LS 2 • Installation of 17 operational systems • In 3 different accelerators: PSB: 8 scanners, previous system is kept for at least one run PS: 5 scanners, no other scanner to backup the new system SPS: 4 scanners, 414 can stay in place, but not ideally placed can we keep the old rotational system for a while ? • We must test the selected acquisition strategy in the 3 machines => Build 3 similar systems and install them in this YETS • Extensive test with various machine conditions. J. Emery 31. 10. 2017

Design inputs for an improved BWS sensor/acquisition system • 1) Dynamic range: The system needs predefined settings (2 parameters) to adapt to the various machines operating points (energy, intensity, revolution period) => Lots of measures have been ‘lost’ during try and error process. • 2) Sensor assembly linearity is perturbed by shower on the PMT => beams with high intensities are difficult to measure (SPS, LHC) • 3) Today’s PMT setup are difficult to operate without linearity distortion (‘saturation’ effects) • 4) Signal transmission limitations (Crosstalk between bunches, noise) • 5) Acquisition modes: Turn by turn / Bunch by Bunch J. Emery 31. 10. 2017

Dynamic range • The system needs predefined settings (2 parameters) to adapt to the various machines operating points (energy, intensity, revolution period) => Lots of measures have been ‘lost’ during try and error process. https: //indico. cern. ch/event/229959/timetable/#20130418 J. Emery 31. 10. 2017

Dynamic range J. Emery 31. 10. 2017 % 10 0 5% 0. 5 % R 7400 U PM and Filter wheel combination

Dynamic range 0. 5 104 J. Emery 31. 10. 2017 5% % DB extraction 21. 07. 2017, PS, 85. V % 0 10

Dynamic range Challenge of the PM optimal operational point Same signal height but… High noise when wire interaction @ 0. 2% => Better to use lower PM gain and high transmission (MSWG 17. 06. 2011) => But experience (Ana & Guido) advised to do the opposite…(less saturation? ) J. Emery 31. 10. 2017

• Sensor assembly linearity is perturbed by the particle shower hitting the PMT => beams with high intensities are difficult to measure (SPS, LHC) • Probably same issue with small PMT (charges collected are reduced, output capability is reduced etc…) SPS: https: //issues/browse/BIWS-298 https: //issues/browse/BIWS-319 https: //issues/browse/BIWS-325 J. Emery 31. 10. 2017 J. J. Gras measures Shower on the PMT

Shower on the PMT Signal A. Guerrero presentation, 27. 02. 2013 J. Emery 31. 10. 2017 PM voltage

PMT linearity distortion MSWG 19. 11. 2010 Measure by Ana/Jonathan J. Emery 31. 10. 2017

PMT linearity distortion • Different mode of operation to take into account. • For example: - PS MTE J. Emery 31. 10. 2017

Signal transmission limitation • Crosstalk between bunches • Was measured in the LHC: 8% for 25 ns spacing LHC Transverse Profile Monitors studies (MD on May 6 th, 2011), ATS/Note/2011/049 (MD) • Seen much larger on the SPS installation • Improved in 2017 by Georges & Stephane, (tunnel amplifier circuit and surface choke) J. Emery 31. 10. 2017

Signal transmission limitation - draft table Machine Energy Detector ? Digitalization Cable length PSB Injection/Extraction Scintillator multi-PMT Surface 65 m PS Injection/Extraction Scintillator multi-PMT Surface 185 -225 m Cables length SPS Injection/Extraction Scintillator multi-PMT Tunnel or Surface 140 – 165 m (517: 88 m) Shower on the PMT Cables length SPS Extraction Diamond Tunnel or Surface 140 – 165 m (517: 88 m) Acquisition dynamic range (if one sensor) LHC Injection/Top Scintillator multi-PMT Tunnel or US/UA 110 m Shower on the PMT LHC Injection/Top Diamond Tunnel or US/UA 110 m Acquisition dynamic range (if one sensor) J. Emery 31. 10. 2017 Potential issue

Acquisition modes • SPS (and LHC) Bunch by Bunch clock available • PSB and PS, another strategy need to be put in place for bunch by bunch • Large scanner speed for high intensities will reduce the number of pts per sigma J. Emery 31. 10. 2017

Conclusion • The selected acquisition need to be tested in 2018 to be ready for service after LS 2 • Still possible to fall back to existing acquisition and improving the current system (PMT selection & powering, scintillator design, etc. . ) • Should we investigate into other detectors: IC + BLM detection chain? High dynamic range + robust, is it fast enough for the turn-by-turn? • Can we postpone the large dynamic range system for later, to be tested during the run after LS 2 J. Emery 31. 10. 2017