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KOPIO Catcher System
RSVP Preliminary Baseline ReviewBrookhaven National Laboratory
April 6, 2005Tadashi Nomura (Kyoto U.)
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 2
Scope of Catcher System
TASK– Detect photons passing through the beam hole– Be insensitive to a vast amount of neutrals in the beam
• In order to avoid false vetoes by beam neutrons and surviving KLs
Required photon efficiency– 99% for photons with E>300MeV
• From the spectrum of photons into the catcher after kinematical cuts (dominated by K2 odd pairing events)
Sensitivity to neutrons– <0.3% for neutrons with Ekin=800MeV
SCOPE
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 3
Concept of Catcher System
SOLUTION– Utilize Cherenkov radiation
• Lead and aerogel tile sandwich counter inside the beamnamed “Aerogel Catcher”
• Lead and acrylic slab sandwich counter near the beamnamed “Guard Counter”
aerogel mirror
Cerenkov light
lead sheet
5inch PMTAerogel Catcher Module
Winston-type funnel
Guard CounterConcept
SCOPE
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 4
Principle of Aerogel CatcherAEROGEL CATCHER
• Lead and aerogel tile counter• Avoid detection of slow particles
from neutron interactions
• Distributed arrangement• Coincidence along the beam
helps us catch forward only
aerogel flat mirror
Cerenkov light
lead sheet
5inch PMTModule
funnel
red: e+/e-, blue: photon
Photon’s EM shower in the module array
AEROGEL CATCHER
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 5
Principle of Guard CounterGUARD COUNTER
• Lead and acrylic slab counter• Slow particle doesn’t emit Cherenkov light
• Utilize the total reflection anglein light transportation
• Cherenkov lights from slow particlesdon’t fulfill the total reflection condition
Photon Neutron
GUARD COUNTER
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 6
Aerogel Counter (WBS 1.2.6.1)In-beam Pb-Aerogel Sandwich
– Module size: 30cm x 30cm– Pb converter: 2mm per layer– Number of modules: 420
• 12-21 in horizontal with beam divergence
• 25 layers along beam(8.3 X0 in total)
– Z gap between layers: 35cm– Coincidence condition
• >= 4 p.e. in 1st layer (A)• >= 2 p.e. in 2nd layer (B)
Top view
12m downstream of main detector
Beam envelope
AEROGEL CATCHER
Module
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 7
Guard Counter (WBS 1.2.6.2)Pb-Acrylic sandwich to cover the halo region• Many soft neutrons around the beam• Lead & acrylic slab sandwich
– Size: 15cm x 15cm– 8 layers of 2mm Pb + 10mm acrylic– Read by 5 inch PMT– 3 modules along the beam– Number of modules: 144
Side View
Front View
beam
Module
GUARD COUNTER
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 8
Expected Photon EfficiencyEXPECTED PERFORMANCE
Aerogel Catcher Efficiency
Y position dependence
99% @ 300MeV
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 9
Efficiencies for Other NeutralsEXPECTED PERFORMANCE
Hit probability for Neutrons
0.3% @ 800MeV
Hit probability for KLs
Dominated by decays in the Catcher
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 10
Proof of PrinciplePrototype 1 (2001-2)
– 1/4 size, flat mirror light yield
Prototype 2 (2002-3)– 1/4 size, parabolic mirror light yield response to proton
(as substitute for neutron) Check single layer eff. /
two-layers’ coincidenceGood agreement
with MC(with gas scintillation)
PT2PT1
PROOF OF PRINCIPLE
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 11
Cost SummaryCOST
Catcher System covered by the contribution from Japan• Japan-US fund• Labor provided by
graduate students
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 12
Costs of Key Components (1)
Aerogel tile– WBS 1.2.6.1.1.1
860 k$
Catalog price by Matsushita
Risk The price of new, transparent tiles (YI-50) not fixed yet
COST
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 13
Costs of Key Components (2)
5 inch Photomultiplier– WBS 1.2.6.1.1.3.1
for Aerogel Catcher735 k$
– WBS 1.2.6.2.1.3.1for Guard Counter
252 k$
Catalog price with usual discount
for mass production(quoted by Hamamatsu)
COST
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 14
Costs of Key Components (3)
Winston-type funnel– WBS 1.2.6.1.1.5
191 k$
Unofficial quotation by Vendor (Yokohama Kikou Co.Ltd.)
E-mail communication
Test ProductionDone in March
COST
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 15
ScheduleSCHEDULE
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 16
Schedule Summary
Schedule and Milestones (2006/07 – 2009/07)– 2006/07 – 2008/09 … Aerogel Counter (WBS 1.2.6.1)
• 2008/06/30 Aerogel tile production completed• 2007/09/27 Delivery of 420 5-inch PMTs completed• 2008/04/01 Winston-type funnel completed
– 2007/10 – 2008/09 … Guard Counter (WBS 1.2.6.2)• 2008/06/30 Delivery of 144 PMTs completed
– 2008/04 – 2009/01 … Front End Electronics (WBS 1.2.6.3)• 2009/01/30 WFD fabrication completed
– 2007/12 – 2008/12 … Shipping (WBS 1.2.6.4)– 2008/10 – 2009/04 … Installation (WBS 1.2.6.5)
• 2009/04/30 Installation completed
– 2009/06 – 2009/07 … Commissioning (WBS 1.2.6.6)
SCHEDULE
April 6-8, 2005 Tadashi Nomura (Kyoto U.) RSVP Preliminary Baseline Review 17
Cost Profile
FY2005FY2006 178k$ 1/6 of AC PMTFY2007 1380k$
829k$551k$
5/6 of AC PMTHalf of Aerogel/optical components
FY2008 1389k$655k$421k$245k$
Half of Aerogel/optical componentsGuard CounterHalf of Front End Electronics
FY2009 204k$188k$ Half of FEE
COST & SCHEDULE