1 / 19

Instrumentation of the Forward Region of the TESLA Detector

Instrumentation of the Forward Region of the TESLA Detector. International Europhysics Conference on High Energy Physics Aachen, July 19th 2003. TESLA. T eV E nergy S uperconducting L inear A ccelerator. Main Parameters Energy: 90 to 800+ GeV

tamra
Download Presentation

Instrumentation of the Forward Region of the TESLA Detector

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. Instrumentation of the Forward Region of the TESLA Detector International Europhysics Conference on High Energy Physics Aachen, July 19th 2003

  2. TESLA TeV Energy Superconducting Linear Accelerator • Main Parameters • Energy: 90 to 800+ GeV • Luminosity (500GeV): 3.4 x 1034 cm-2 s-1 • Beam size (500 GeV): 553 x 5 nm • Physics Potential • Precision measurements and searches in: • Higgs physics • Supersymmetry • EW precision tests (GigaZ) • QCD and top thysics • yet unimagined physics Karsten Büßer, EPS-HEP Conference Aachen

  3. The TESLA Detector • Detector Concept • Precision vertex detector • Large gas filled central tracking detector • Highly segmented calorimeters • 4T magnetic field, tracking detectors and calorimeters inside the coil Karsten Büßer, EPS-HEP Conference Aachen

  4. Beam Induced Backgrounds Main background source for the detector are beamstrahlung pairs Karsten Büßer, EPS-HEP Conference Aachen

  5. GEANT3simulation of 10 pair particles Tasks for the Forward Region • Shielding of the tracking detectors against backscattered beamstrahlung background • Provide instrumentation for: • Precision luminosity measurement • Hermeticity: • Extension of the energy flow measurement down to small angles • Beam diagnostics Karsten Büßer, EPS-HEP Conference Aachen

  6. TESLA Forward Calorimeters • Instrumented tungsten mask • Two calorimeters: • LAT • Low Angle Tagger • 27.5 – 83.1 mrad • actual task :„Luminosity Calorimeter“ • LCAL • Luminosity Calorimeter • 4.6 – 30 mrad • actual task: „Beam Calorimeter“ Karsten Büßer, EPS-HEP Conference Aachen

  7. Luminosity Measurement Physics Requirements:ΔL/L≈ 0.02% (GigaZ) Process: e+ e-→ e+ e- elastic Bhabha Scattering e+ e-→ e+ e-γ radiative Bhabha Scattering Statistics: for L= 3.4 x 1034 cm-2 s-1 rate R ≈ 170 Hz Systematics: • from detector acceptance: since σtot(Θmin,Θmax) ~ Θmin-2 – Θmax-2 ≈ Θmin-2 then ΔL/L= 2ΔΘmin/Θmin with Θmin= 27.5 mrad, ΔL/L= 10-4ΔΘmin= 1.4 µrad (!) • from theory: At LEP achieved: 5.0 x 10-4 Karsten Büßer, EPS-HEP Conference Aachen

  8. Low Angle Tagger Geometry (as defined in the TESLA TDR) • 14 cylinders in Θ • 24 sectors in Φ • 40 rings in z • 13440 cells in MC studies • Conical Setup • r: 4 – 12 cm • (not affected by • beamstrahlung pairs) • z: 140 – 200 cm • Silicon/Tungsten sandwich • 40 X0 The LAT serves as a shield ! Karsten Büßer, EPS-HEP Conference Aachen

  9. Energy Response Energy Resolution LAT Performance GEANT3 simulation studies show the response to high energetic electrons Karsten Büßer, EPS-HEP Conference Aachen

  10. LAT Performance Energy Response and Resolution Angular Resolution Red: Cut on desposited energy (>2.5 GeV) Karsten Büßer, EPS-HEP Conference Aachen

  11. LAT Outlook • New TESLA beam optics are under development which would allow to move the quads out of the detector (increasing l* from 3m to ≤5m). • Mask and calorimeters would move • Flat LAT seems possible • Simulation studies for a flat LAT are under way → angular resolutions down to 1.4 µrad are still challenging! • Alignment tolerances for detectors are stringent: • Δz < 60 µm • Δr < 0.75 µm • Alignment monitor system probably needed TESLA-TDR l*=3m Design study l*=4.1m Karsten Büßer, EPS-HEP Conference Aachen

  12. The LCAL Technology options under study: • Diamond -Tungsten Sandwich, rm~ 1cm • Crystal PbWO4, rm~ 2cm 30 layers, 30 X0 Karsten Büßer, EPS-HEP Conference Aachen

  13. LCAL and Pair Background Deposited Energy, Diamond/W Pairs from Beamstrahlung per bunch crossing (BX) Produced: #: ~130000, Etot: ~360 TeV on each LCAL: #: ~15000, Etot: ~20 TeV Dose: ≤ 10 MGy/y Karsten Büßer, EPS-HEP Conference Aachen

  14. LCAL as Beam Monitor nominal beam • Number of produced pairs is a measure of the luminosity • Deposited energy on the LCAL is input for the TESLA fast feedback system • rΦ energy distribution on the LCAL is an indicator for beam misalignments tilted beam: x‘=3.5 mrad Karsten Büßer, EPS-HEP Conference Aachen

  15. LCAL as Physics Device One 250 GeV electron and pair background from one BX Generated Background added Reconstructed Karsten Büßer, EPS-HEP Conference Aachen

  16. Reconstruction Simple algorithm: • subtract average (10 BX) background • search for cells with signal > 3σ of background fluctuation • require longitudinal chain of signal cells 4.6 mrad 30 mrad Karsten Büßer, EPS-HEP Conference Aachen

  17. Energy Resolution of the LCAL Energy resolution is dominated by the background Karsten Büßer, EPS-HEP Conference Aachen

  18. Fake Rates 500 BX Karsten Büßer, EPS-HEP Conference Aachen

  19. Conclusion • LAT • Luminosity measurment with 0.02% accuracy will be challenging • LCAL • Several technologies are under study • Detection of high energetic electrons is possible with high efficiency below 10 mrad • Energy resolution is dominated by background subtraction • Need to look into more clever algorithms • OUTLOOK • TESLA interaction region might change (increasing l*) • Redesign of the forward region, impact on calorimeters ? • R&D has started Test stand for Si and Diamond sensors in Zeuthen Karsten Büßer, EPS-HEP Conference Aachen

More Related