1 / 30

Fast luminosity measurements and MDI questions for super B factories A_RD_8_2012

This workshop aims to collaborate and exchange on simulating and comparing background and particle loss processes, as well as fast luminosity monitoring methods for Super B Factories.

rruppert
Download Presentation

Fast luminosity measurements and MDI questions for super B factories A_RD_8_2012

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Philip Bambade LAL: P.B., F. Blampuy (grad. student), C. Rimbault (Acc. Dept.), F. Bogard & S. Wallon (mechanical eng.) KEK: S. Uehara, Y. Funakoshi, M. Iwasaki Fast luminosity measurements and MDI questions for super B factoriesA_RD_8_2012 Joint TYL-FKPPL workshop, Clermont-Ferrand 28-30 May 2012

  2. Y. Ohnishi (KEK, joint bkgd w.s., Feb. 2012

  3. ILC CLIC ATF2 Super-KEKB Super-B Parameters 4-7 4.18-6.7 Beam Energy [GeV] 1.3 250 1500 L* [m] 1 3.5 - 4.5 3.5 0.47-1.3 0.6 x/y [m.rad] 5 10-6 / 3 10-8 10-5 / 4 10-8 6.6 10-7 / 2 10-8 2-3.3 10-5 / 0.5-1.2 10-7 25-32 / 0.2-0.4 IP x/y [mm] 4 / 0.1 21 / 0.4 6.9 / 0.07 IP ’ [rad] 0.14 0.0094 0.00144 E [%] ~ 0.1 ~ 0.1 ~ 0.3 0.08 - 0.06 0.05 Chromaticity ~  / L* ~ 104 ~ 104 ~ 5 104 1.7-3.2 103 Number of bunches 1-3 (goal 1) ~ 3000 312 978 Number of bunches 3-30 (goal 2) ~ 3000 312 978 Bunch population 1-2 1010 2 1010 3.7 109 5.08-6.56 1010 IP y [nm] 37 5.7 0.7 59 36 ATF2 = scaled ILC & CLIC final focus

  4. Luminosity operational mode & backgrounds / MDI design dominated by several beam loss processes Y. Funakoshi (KEK, joint bkgd w.s., Feb. 2012 ee eeee process (pair bkdg in VD) M. Boscolo (LNF, SuperB meeting, March 2012

  5. Aim of A_RD_8_2012 is to collaborate & exchange on: • simulating & comparing several background / particle loss processes • fast luminosity monitoring methods

  6. Radiative Bhabha (“Compton”) process Represents major background source via particle loss after IP can be used for luminosity monitoring  ~ 250 mbarn (E > 1% Ebeam )

  7. F. Blampuy (LAL)

  8. Different EPA factorization methods F. Blampuy (LAL)

  9. Y. Funakoshi (KEK, joint bkgd w.s., Feb. 2012 Macroscopic quantum effect… issue for luminosity monitoring ?

  10. Where are the signals? R-side L-side Recoilelectron g from positron LER HER Recoilpositron Outside g from electron 12

  11. Specifications and rates Ground motion analysis and experience from Belle & PEP-II Relative accuracy <10-3 at 0.1-1 kHz Detected particles >106 at 0.1-1 kHz L ~ 1036 cm-2s-1 ~ 250 mbarn (E > 1% Ebeam )  expected total rate ~ 250 106 / 0.001 s Should also work for lower initial luminosities: 102-4 range

  12. Possible locations R-side L-side Deflected e- g, e+-side Deflected e+ g, e--side Outside Downstream magnets from Masuzawa-san Possible problems: Material quantity of the beam chamber in r.l. Undesirable sensitivity to angle and position/size of the beams at IP 14 S. Uehara and Y Funakoshi (KEK)

  13. F. Blampuy (LAL) 2 candidate locations in SuperB LER Estimated counting rate in 5  5 mm2diamond sensor placed 3.5 cm from beam ~ 5 106 / 0.001 s Mechanical adjustment and / or structure with variable size strips can provide some dynamic range 5 cm

  14. Hyojung Hyun (LAL, KNU)

  15. Hyojung Hyun (LAL, KNU) 1st test @ LAL, April 2012 ABCD Project ATF2 Beam halo and Compton electron Diamond sensor project Frédéric Bogard (LAL)

  16. LER Loss Position & Rate Y. Funakoshi (KEK) 0.1mA/s -> 6.2GHz 18

  17. Loss pointの座標（transverse） 4m < s < 16m (sはIPからの距離) Y. Funakoshi (KEK) 19

  18. Expected ZDLM rate (Uehara) 0.1mA/s -> 6.2GHz • Funakoshi-san’s coefficient • The rate should be proportional to luminosity 1035 luminosity --- ~ 1GHz • Effective detector length --- ~ 0.1m • Efficiency --- 10% (angular coverage and shower loss) Expected Rate --- 0.1mA/s  10 MHz LER 4 m point (upstream BLC1LP) ~ 2MHz @1035 9 m point (downstream BLC1LP) ~ 8MHz @1035 13 m point (downstream QKBLP) ~ 30MHz @1035 QKBLP- skew -- Efficiency may drop (spread to non-horizontal direction) 20

  19. Readout Methods 1. Counting rate -- proportional to Luminosity Rate < 1% of Collision rateto avoid overlaps, (< 2.5MHz) Collision rate (2-bucket spacing) 250MHz ~1035 1MHz --- 1% stat. accuracy in 100Hz readout ~1034 100kHz --- 3% stat. accuracy in 100Hz readout Tune depends on Luminosity Charge amp (Makes slow change) →　V/F conversion(1MHz max) for Feedback @ SuperKEKB Analog input (with pulse overlaps) is also OK in this scheme? 21

  20. Check for any Touschek or beam gas scattering losses in candidate areas for fast luminosity monitoring

  21. Work plan (KEK, LAL) A bit more advanced… Experience from KEKB  ZDLM @ SuperKEKB/Belle II could be necessary, possible and should be prepared. • Choices for hardware and location undergoing. • Aiming full-duty factor in the high rate • Wide L range 1031 – 1036 /cm2/s • Simulation study for dithering (active feedback) is performed  Fast luminosity monitor(s) being investigated for SuperB • Further checks / comparisons of cross-section and generator • MAD tracking in lattice to define best locations • GEANT4 for acceptance and detector layout optimization • Requirement on beam pipe shape from HOM (for photon detection) • Vacuum chamber design and magnet shapes, synchrotron rad. • Background from non-L scaling beam losses: Touschek, beam gas • Diamond sensor implementation (for ATF2 beam halo) and characterization • Readout (for ATF2, Parisroc2 front-end electronics OK  also for superB ?) Starting effort… Some synergies with ATF2 / LC R&D Connected to LNF, BINP and JAI teams

  22. Interesting collaboration prospects between LAL and KEK and between SuperB / SuperKEKB ! F. Blampuy, studentf C. Rimbault LAL/IN2P3 CR2

  23. Additional slides

  24. HER Loss Position & Rate Y. Funakoshi (KEK) 0.1mA/s -> 6.2GHz 26

  25. Loss pointの座標（transverse） 4m < s < 16m Y. Funakoshi (KEK) 27

  26. Readout Methods 2. Bunch-by-Bunch Luminosity Readout --- Trying a method to use pipeline TDC AMT3/COPPER (Belle standard) Time step 738ps No dead time, if word count is not too large. Under tested @ test bench Thank to Higuchi-san Test Condition: 2MHz ~ 1 %/bunch-collision for 2000-bunch operation ~20 hit/rev, ~ 1000 cps/bunch Data amount: ~ O(10) MB/sec in raw data --- transfer only count-data via network (after histograming) : only ~100KB every second 28

  27. Near term planning • R&D grant from P2IO LABEX covering 2012-2014 PhD grant from CSC-FCPPL (S. Liu, 3 years starting 09-2012) Collaboration with KNU and post-doc application (H. Hyun, H. Park) • Design / lab test at LAL : mechanics, electronics (PARISROC2) and more detailed simulations. Experience from FCAL coll. at DESY-Zeuthen. • New vacuum chamber fabrication and quadrupole installation at KEK • Aim to test 1st prototype in ATF2 beam  end 2012 / early 2013 tentative schedule

More Related