The focusing mirror system

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

Hit prob

Hit prob > 3 10-4

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

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

Wrong ID example: