1 / 22

“THE OLYMPUS LUMINOSITY MONITORS” Ozgur Ates Hampton University

“THE OLYMPUS LUMINOSITY MONITORS” Ozgur Ates Hampton University. *. * Supported by NSF grant No. 0855473. A R eview of the MC S tudies of t he L umi M onitor s Some GEM Reports from PREX at JLAB April 26-27 OLYMPUS MEETING at DESY. Luminosity Monitors: Telescopes.

khalil
Télécharger la présentation

“THE OLYMPUS LUMINOSITY MONITORS” Ozgur Ates Hampton University

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. “THE OLYMPUS LUMINOSITY MONITORS” Ozgur Ates Hampton University * * Supported by NSF grant No. 0855473 • AReview of the MC Studies of the LumiMonitors • Some GEM Reports from PREX at JLAB April 26-27 OLYMPUS MEETING at DESY

  2. Luminosity Monitors: Telescopes Luminosity monitors for LEPTON in coincidence withRecoil PROTON detected in the opposite sector, and vice versa. 2 tGEM telescopes, 1.2msr, 12o, R=187/237/287cm, dR=50cm, 3 tracking planes Forward telescopes PROTON LEPTON 12o LEPTON PROTON TOF

  3. Control of Systematics Triple Super Ratio: Run the Exp. For the “4 different states” i= e- vs e+ j=toroidalmagnet polarity(+-) Repeat cycle many times Ratio of luminosities Ratio of acceptances (phase space integrals) Ratio of counts • Forward-angle (high-epsilon, low-Q) elastic scattering (se+ = se-) means there is no two-photon exchange • Separately determine three super ratios • Left-right symmetry = Redundancy

  4. Forward Elastic Luminosity Monitor • Forward angle electron/positron telescopes or trackers with good angular and vertex resolution • Coincidence with proton in BLAST • High rate capability • It will be built at Hampton University this year! • GEM Technology MIT prototype: Telescope of 3 Triple GEM prototypes (10 x 10 cm2) using TechEtch foils F. Simon et al., NIM A598 (2009) 432

  5. Monte Carlo Studies by using Geant4 • Generated and reconstructed variables Theta, Phi, Momentum, Z(vertex) • Proton& Electron • Resolutions δZp, δTp, δPhp, δPp, δZe, δTe, δPhe, δPe • Residuals: Redundancy of variables / elastic scattering • 4 variables: Pe, Pp, Te, Tp • 3 constraints: 3 conservation equations4 – 3 = 1 (DEGREES OF FREEDOM) • TeTp: Te – Te(Tp) • TePe: Te – Te(Pe) • TePp: Te – Te(Pp) • Coplanarity: • PhePhp: Phe – Php – 180 • Common vertex:ZeZp: Ze – Zp

  6. Resolution: generated-reconstructed 100micron, 50cm, LuMo+BLAST (Te=0-80 dg, Phe=+-15 dg) δZp δZe δTp δTe δPhe δPhp δPp δPe

  7. Resolution: generated-reconstructed 100micron, 50cm, LuMo only (Te=6-13 dg, Phe=+-5 dg) δZp δZe δTp δTe δPhe δPhp δPe δPp

  8. Residuals: TeTp=Te-TeTp (one sample)

  9. Design Parameters: Resolutions • Many configurations were simulated. • Varied intrinsic res. and distance between tracking planes. • 100 µm intrinsic res. and 50 cm gap between Gem1/2 and Gem2/3 show the optimum performance.

  10. Conclusions • 10x10 cm2GEM detector size for active area at 12 degree. • Least distance of first element 187cm for clearance • The second should sit 237cm and third gem 287cm away from the target. • Elastic count rate still sufficient with 50cm gaps • 100 µmintrinsic resolutions of GEM’s meetthe experimental requirement.

  11. Next Steps • Simulations of phase space integral(s), acceptance; expected counts • Study of systematic effects (beam offset, slope, width; etc.) on counts per bin • Simulation of backgrounds • Build and test the detectors by end of this year! • Implement in OLYMPUS in 2011, run in 2012

  12. The 208PbRadius Experiment ("PREX")

  13. The X position of a VDC Track projected onto the GEMThis value is about +/- 0.1 (units are m)

  14. GEM Hit Pos vs Projected VDC Pos

  15. Resolutions ~3mm= GEM Hit Pos – Projected VDC Pos on X & Y(UVA & INFN)

  16. ADC Spectrum (Entry<50000)Pedestal and Noise Suppressed

  17. ADC Correlations UVA and INFN

  18. ADC values vs Strips(=248) are fired event by event(=50000)

  19. The size of the reconstructed clusters in strips(140 micron strip pitch) events=50000

More Related