1 / 30

Beam Monitoring from Beam Strahlung: Observables, Analysis Concepts, and Next Steps

Explore beam diagnostics through beam strahlung monitoring, analytical concepts, and future directions in a research collaboration involving summer students and experts in the field.

arlena
Download Presentation

Beam Monitoring from Beam Strahlung: Observables, Analysis Concepts, and Next Steps

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. Beam Monitoring from Beam Strahlung • work by summer students • Gunnar Klämke (U Jena, 01) • Marko Ternick (TU Cottbus, 02) • Magdalena Luz (HU Berlin, 03) • Regina Kwee (HU Berlin, 03) • New student, summer 04 Achim Stahl DESY Zeuthen 16.Apr.2004

  2. Beam Strahlung Diagnostics of bunches at IP GeV/mm2 • 3 potential sources of information • energy-distribution of pairs • number-distribution of pairs • distribution of photons • Over-simplified detector simulation • detectors subdivided into cells • sum energy impact on cells • main source of uncertainty •  stat. fluctuations of beam-str. Linear approximation

  3. Redesign for larger L*

  4. D A C B Observables • total energy • first radial moment • first moment in 1/r • thrust value • angular spread • E(ring ≥ 4) / Etot • (A + D) – (B + C) • (A + B) – (C + D) • E / N forward / backward calorimeter

  5. Taylor Matrix Observables Observables Δ BeamPar = + * nom Current Analysis Concept • Beam Parameters • determine collision • creation of beamstr. • creation of e+e- pairs • guinea-pig • Observables • characterize energy distributions in detectors • analysis program 1st order Taylor-Exp. Solve by matrix inversion (Moore-Penrose Inverse)

  6. parametrization (polynomial) 1 point = 1 bunch crossing by guinea-pig slope at nom. value  taylor coefficient i,j Slopes observable j beam parameter i

  7. Example: Slopes

  8. 1st Results: Single Parameter Analysis

  9. What’s new: • consolidation of code • new observable: E(ring ≥ 4) / Etot • normalization of observables O/σ • use of external measurments • first look at real bunch trains

  10. Single Parameter Analysis

  11. Single Parameter Analysis Test of Linearity Range

  12. Single Parameter Analysis weight of individual observables

  13. Two Parameter Analysis Example: horizontal beam size Sngl Param Reso: 1.5 nm

  14. Multi Parameter Analysis σx Δσx σy Δσy σz Δσz 0.3 % 0.4 % 3.4 % 9.5 % 1.4 % 0.8 % 1.5 % 0.9 % 0.3 % 0.4 % 3.5 % 11 % 0.9 % 1.0 % 11 % 24 % 5.7 % 24 % 1.6 % 1.9 % 1.8 % 1.1 % 16 % 27 % 3.2 % 2.1 %

  15. Multi Parameter Analysis Test with non-nominal bunches: e- e+ nom. bunch size x: 575nm 575nm 553nm bunch size y: 5nm 7nm 5nm bunch size z: 290μm 320μm 300μm

  16. Full Analysis

  17. Real Beams: first look Example of 2 observables:

  18. Real Beams: first look Single Parameter Analysis: σx

  19. LumiCal 1st layer: measures N all layers: measure E 3 Sources of Information • energy-distribution of pairs • number-distribution of pairs • distribution of photons up to now: only energy distribution of pairs used test: number-distribution of pairs • new observable • Npairs / Etot

  20. Number Distribution weight of new variable

  21. Number Distribution Example: 6-Par. Analysis  roughly 10% improvement

  22. First Look at Photons

  23. σx = 650 nm σy = 3 nm First Look at Photons nominal setting (550 nm x 5 nm)

  24. Conclusions: • Interesting resolutions achieved from single bunches • Multi-parameter analysis possible • Electron – Positron bunch can be separated • Not all parameters measurable Next Steps: • Include non-linear terms • understand realistic beam simulation • include photons ? impact on calorimeter design ?

  25. 1st Fit with non-linear Terms

  26. 1st Fit with non-linear Terms

  27. The Mask • LumiCal shields detector against • back scattered beam strahlung • synchrotron radiation of final focus QUADs • neutrons from the dump

  28. The Mask • LumiCal shields detector against • back scattered beam strahlung • synchrotron radiation of final focus QUADs • neutrons from the dump 5 cm graphits 10 cm graphits

  29. VTX-Detector: Simulations by Karsten Büsser, Hamburg

  30. Simulations by Karsten Büsser TPC: TDR slight increase in background ? optimization possible ?  more in Paris new: 20 mrad crossing new: 0 crossing

More Related