1 / 6

Impact of Beam-Gas Scattering on Detector Background in Geant Simulations at SLAC

This paper by T. Maruyama from SLAC discusses the simulation of beam-gas scattering in the Beam Delivery System (BDS) using Geant 3. Comparisons with Keller's TURTLE results indicate consistency within a factor of two. The beam line vacuum is modeled as a mixture of gases, and it explores how synchrotron radiation masks at varying distances affect scattering rates. The study estimates detector background from scattered particles in the SiD Detector, revealing that adequate protection measures significantly reduce background levels, emphasizing the importance of careful collimator placement.

kelly-williams
Télécharger la présentation

Impact of Beam-Gas Scattering on Detector Background in Geant Simulations at SLAC

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-gas scattering & detector background T. Maruyama (SLAC)

  2. Beam-gas scattering in Geant 3 • Few years ago beam-gas scattering in the BDS was simulated in Geant and compared with Keller’s TURTLE results. • Consistent within a factor of two. • In Geant the beam line vacuum is replaced by a mixture of 62%H2+ 22%CO+16%CO2 at a pressure of 4.9x10-3 atm • X0 = 1500 m  100 • Sync radiation masks (FD protection collimators) at 50 m and 13 m take most of the beam-gas scatterings. • Detector background

  3. Beam-gas scattering rate at 10 nTorr

  4. Detector background from beam-gas scattered particles hitting the mask at 13 m SiD Detector with 14 mrad crossing angle 13 m Mask Central detector is well protected. Negligible detector background would be generated unless particles hit the mask edge within ~10 um.

  5. Detector background from 250 GeV e- hitting the 13m mask Photons from pairs ~1000/BX VXD hits from pairs ~300/BX

  6. Conclusions • Protection Collimators at 13 m and 50 m would take most of beam-gas scattered particles. • 1.8 hits/BX at 50 m @10 nTorr • 0.22 hits/BX at 13 m @ 10 nTorr • Detector background from particles hitting the 13m mask was estimated. • To be comparable with the pairs background, ~100 particles must hit the mask edge within 10 um.

More Related