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Report from Japan Group Beam Catcher. N. Sasao / T. Nomura (Kyoto U.) Contents : Status of Japan Group Progress in Beam Catcher Test of Aerogel’s Light Yield Beam test with 60MeV electrons Optical properties of Aerogel tile 2 nd prototype to study response to protons.
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Report from Japan GroupBeam Catcher N. Sasao / T. Nomura (Kyoto U.) Contents : • Status of Japan Group • Progress in Beam Catcher • Test of Aerogel’s Light Yield • Beam test with 60MeV electrons • Optical properties of Aerogel tile • 2nd prototype to study response to protons KOPIO Collaboration Meeting
Institutional Issues Status of Japan Group • Member Kyoto U.N.Sasao, T.Nomura, T.Sumida (M2), H.Morii (M1) KEKM.Kobayashi, T.Taniguchi Kyoto U. of EducationR.Takashima • Funding in this year • Japan-US Cooperation 80k$ (JFY02) • Grant in Aid for Scientific Research100k$ (JFY02, 700k$ in total till JFY2005) Two new graduated students…= Our main man-power!! KOPIO Collaboration Meeting
Progress in Beam CatcherTest of Basic Performance Proof-of-Principle module => 1st Mini Prototype • Lead-Aerogel Module • Aerogel n=1.03 • Stack of 4 tiles (11cm x 11cm x 1.1cm each) • 2mm/20mmt Lead converter • 5-inch PMT • Plane reflecting mirror • No light funnel • Tested in Dec.,2001 at KEK • 70% of expected light yield • Unwanted accidentals hid the proton reaction behavior KOPIO Collaboration Meeting
Rate (Hz) Injection Test Area Time after Injection (minutes) Futher study on Aerogel’s Light YieldTest with 60MeV electrons • Electron Strecher Ring in Uji-campus, Kyoto U. • Beam energy = 60MeV • Slow extraction by RF knock-out method • Easy to use (Need daily-basis tuning only) KOPIO Collaboration Meeting
Photoelectron yield I(1-1/n2b2) Ring Image Futher study on Aerogel’s Light YieldLight Yield and Ring Image MC assuming n=1.03and norm’d at 1GeV/c 60MeV e- 1-2GeV/c p+ (KEK) (10% discrepancy comes from mis-tuning of light path length in MC) KOPIO Collaboration Meeting
Aerogels’s Light YieldTransmittance of Aerogel Tile • Aerogel’s optical properties determine light yield • Transmittance (Photo-spectrometer : Shimadzu MPS-2000) • Described with absorption and scattering(s) Rayleigh (1/l4) + additional scattering, for ex., Mie (1/l)… • Obtain similar results to those in HERMES’s paper • P1=92%, P2=0.01mm4 • Dirty surface causes additional scattering effect, which has different wavelength dependence Bad c2 KOPIO Collaboration Meeting
5inch PMT Beam Mirror Pb sheets Aerogel tiles Response to Proton2nd Mini Prototype • To study response to protons … PMT must be far/shieldedfrom interaction point(experience from test in Dec., 2001) • New features • 5-inch PMT, located at 35cm apart from beam line • An-isometric parabolic mirror z = x2/4fx + y2/4fy, fxfy • Test at KEK in coming September KOPIO Collaboration Meeting
Progress in Beam CatcherSummary • Further test with 1st mini prototype • Light yield study with 60MeV electron at Kyoto U., Uji • Ring size/width are OK • Light yield is 10-20% smaller than MC expected • Transmittance of Aerogel tile • As expected, but care must be taken when handling tiles • Construct 2nd mini prototype • To study response to protons • Test at KEK in September • New optical element (an-isometric parabola)an exercise to fabricate “real” optics KOPIO Collaboration Meeting