410 likes | 587 Views
Full-detector simulation. Full simulation. GEANT4-based (“QGSP_BERT_HP”) Whole detector implemented No beam line elements |z|>4m (further geometry is urgent) - No showers/neutrons from tunnel ! Input:
E N D
Full-detector simulation Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Full simulation • GEANT4-based (“QGSP_BERT_HP”) • Whole detector implemented • No beam line elements |z|>4m (further geometry is urgent) - No showers/neutrons from tunnel! • Input: • Track particles by SAD until they hit beam pipe wall, record position and momentum, then pass that information to GEANT4 (Touschek/Beam-gas) • BBBrem particles are tracked from IP by SAD until they hit beam pipe wall, record position and momentum, then pass that information to GEANT4 (RBB) • Use KoralW output directry in GEANT4 (2photon) • First campaign was in Dec. 2011 • 0.9GHz Touschek LER /2-photon • Second Campaign in Feb. 2012 (coming soon) • Touschek/Beam-gas/Rad. Bhabha/2-photon We need to check: -True event signals are not hidden by fake background hits? -Our detectors/readout electronics are not severely damaged by radiation or neutrons? Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Whole geometry ready in GEANT4 CDC CDC BKLM Solenoid SVD TOP Structure EKLM ARICH ECL PXD PXD Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Total BG R-side L-side 1GeV ,1GHz =0.16W
Background picture at Belle-II BKLM EKLM RBB LER RBB HER ECL RBB HER 1turn TOP Touschek HER ARICH CDC SR Neutrons (rad. Bhabha) Neutrons (rad. Bhabha) LER e+ HER e- Coulomb HER Coulomb LER Touschek LER 2m -3m -2m -1m 1m 3m 0m 5 H.Nakayama (KEK)
Background in 1st campaign LER e+ 1GHz e+ Touschek LER Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Materials in simulation Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Beam pipe and Tungsten shield Additional Tungsten Tungsten Vertical cross section EM shower Horizontal cross section 4mm of Ta beam pipe(1X0), ~1cm of Tungsten shield(~3X0) • Paraffin, • Ti (X0=35.6mm), • Ta (X0=4.3mm) • W (X0=3.5mm) Protect PXD/SVD from EM showers generated by IR loss Be part is too thin to be seen Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
QCS cryostat • Space limited! • cables, pipes should sit here • Additional shield for RBB? • (not shield here in current GEANT4) CDC Air, Liq_He SUS316L (X0=17mm), Fe (X0=~18mm) SC_COIL(X0=~16mm), Ta (X0=4.3mm) 4mm of Ta beam pipe (1X0), few cm of iron+coil (~2X0) , and few cm of SUS structure(~2X0) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Full-detector simulation Generated vertex of all MC particles LER e+ ~500 e+ hit (4GeV) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Rad. Bhabha LER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 464 events in 100ns
Rad. Bhabha LER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 464 events in 100ns
Rad. Bhabha HER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 284 events in 100ns
Rad. Bhabha HER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 284 events in 100ns
Total (w/o SR, 2-photon) Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] in 100ns
Total (w/o SR, 2-photon) Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] in 100ns
2ndcampaign PXD A. Moll (MPI) VXD meeting on 7th Feb. 2012 LER Touschek (0.2GHz) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
2ndcampaign PXD A. Moll (MPI) VXD meeting on 7th Feb. 2012 Requirement: occupancy <2% Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign SVD P. Kvanicica 10th Belle2 General Meeting (19 Nov. 2011) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign CDC M. Uchida 10th Belle2 General Meeting (19 Nov. 2011) Hit rate Code under development .. Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign TOP M. Petric 10th Belle2 General Meeting (19 Nov. 2011) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign K/pi separation K. Inami 10th Belle2 General Meeting (19 Nov. 2011) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign ARICH L. Santej 10th Belle2 General Meeting (19 Nov. 2011) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign BKLM L. Piilonen 10th Belle2 General Meeting (19 Nov. 2011) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign EKLM T. Uglov 10th Belle2 General Meeting (19 Nov. 2011) Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
neutron damage /radiation dose BKLM inner layers Whole EKLM ECL Photo diodes TOP readout electronics Typical numbers: neutron: 1011 eqn/cm2/year dose: 100Gy/year CDC readout electronics boards ARICH HAPD Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
1st campaign Neutron flux 1MeV equivalent rate 1 year = 107 sec Should be updated in 2nd campaign 29 H.Nakayama (KEK)
1st campaign Radiation dose These numbers were not correct. Need to be updated in 2nd campaign. 1 year = 107 sec Should be updated in 2nd campaign Impact from Touschek BG is tolerable in terms of neutron/radiation dose. Next step is to see the impact from other BG sources, such as beam-gas BG, radiative Bhabha BG, SR, etc.. 30 H.Nakayama (KEK)
Summary • Touschek, beam-gas have been reduced, now radiative Bhabha dominates. (Same as SuperB!) • I hope we can understand the 2-photon number discrepancy today • SR simulation in full simulation started recently • Full detector simulation campain ongoing Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
backup Belle-II/SuperB Joint BG meeting (Feb. 9-10, 2012)
Touschek LER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 15 events in 100ns
Touschek LER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 15 events in 100ns
Touschek HER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 3 events in 100ns
Touschek HER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 3 events in 100ns
Coulomb LER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 5 events in 100ns
Coulomb LER Magenta: primary particle Red: e+ Blue: e- Yellow: gamma Green: neutron Show particles with E>1MeV Sqrt(x*x+y*y)*sign(x)[cm] z[cm] 5 events in 100ns