the focusing mirror system
DESCRIPTION
The focusing mirror system. spherical (elliptical) mirror within gap volume for backward refl. plane mirror just beyond radiator for forward reflections. Minimize detector area (~1 m 2 /sector) interference with FTOF. TOF. Low material budget. Reflecting inside. direct & - PowerPoint PPT PresentationTRANSCRIPT
The focusing mirror systemThe focusing mirror system
Preliminary studies with mirrors (to reduce instrumented area): - focalization capabilities shown - ring patterns for positive and negative mesons at different angles and momenta reconstructed
• spherical (elliptical) mirror within gap volume for backward refl.
• plane mirror just beyond radiator for forward reflections
Different scenarios (refractive index, radiator thickness, mirror geometry) are being explored
TOF
Reflectinginside
direct &reflected
Low materialbudget
Minimize detector area (~1 m2/sector) interference with FTOF
Unidentified events: reduced by better treatment of unwanted events (i.e. muon from meson decay)
Mismatch in number of N p.e.: wrong seed assignment
Protons weird probability: feature of the LH definition close to the threshold
Hit prob
Hit prob > 3 10-3
200 trials per point
Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm
Mirror: 14-25o
PMTs: UBA
Direct ring example:
Hit prob
Hit prob > 3 10-3
200 trials per point
Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm
Mirror: 14-25o
PMTs: UBA
Hybrid ring example:
200 trials per point
Aerogel: - n=1.06
- thick. increasing with radius: 2-4-6-8-10 cm
N p.e. > 5 for reflected ringsN p.e. > 12 for direct rings
Average N p.e. : Mirror 14-25o PMTs: UBA
200 trials per point
Aerogel: - n=1.06
- thick. increasing with radius: 2-4-6-8-10 cm
Low angles more challengingPossibly due to limited number of trials
LH-LHk,p : Mirror 14-25o PMTs: UBA
Protons benefit the smallnumber of unfired PMTs whit expected signal(P is small when C=0)
Protons benefit the smallnumber of unfired PMTs whit expected signal(P is small when C=0)-
200 trials per point
Aerogel: - n=1.06
- thick. increasing with radius: 2-4-6-8-10 cm
Average N p.e. : Mirror 14-25o PMTs: UBA
Mandatory for positive hadronsBenefit for negative hadrons at large angles and small energy
Mandatory for positive hadronsBenefit for negative hadrons at large angles and small energy
Big dot = studies show in the previous slide
Average N p.e. : PMTs: UBA
Mirror 14-25o Mirror 14-35o
Worse for positive hadronsBetter for negative hadronsWorse for positive hadronsBetter for negative hadrons
LH-LHk,p : PMTs: UBA
Mirror 14-25o Mirror 14-35o
Worse for positive hadronsBetter for negative hadronsWorse for positive hadronsBetter for negative hadrons
200 trials per point
Aerogel: - n=1.06
- thick. increasing with radius: 2-4-6-8-10 cm
Average N p.e. : PMTs: UBA
Mirror up to 35o:Worse for positive hadronsBetter for negative hadrons
Mirror up to 35o:Worse for positive hadronsBetter for negative hadrons
Average N p.e. : Mirror 14-25o PMTs: UBA
n=1.06Aer. thick 2-4-6-8-10 cm
n=1.03Aer. thick 3-6-9-12-15 cm
n=1.03 gives less photons regardeless the increase thickness due to same assumed transmission lengthn=1.03 gives less photons regardeless the increase thickness due to same assumed transmission length
LH-LHk,p : Mirror 14-25o PMTs: UBA
n=1.03 still good due to the larger Cherenkov angle separationn=1.03 still good due to the larger Cherenkov angle separation
n=1.06Aer. thick 2-4-6-8-10 cm
n=1.03Aer. thick 3-6-9-12-15 cm
200 trials per point
Aerogel: - n=1.06
- thick. increasing with radius: 2-4-6-8-10 cm
Average N p.e. : PMTs: UBA
n=1.06 better for patter recognition in the presenceof backgrouns
n=1.06 better for patter recognition in the presenceof backgrouns