Download
1 / 17
170 likes | 354 Views
Cosmic veto system basic setup for Phase-I. Drutskoy, ITEP, Moscow. COMET collaboration meeting CM11. September 30 - October 3, Dubna, Russia. A. Drutskoy, ITEP Cosmic veto system basic setup for Phase-I Dubna, Sep 30- Oct 3 1.
E N D
Cosmic veto system basic setup for Phase-I • Drutskoy, ITEP, Moscow COMET collaboration meeting CM11 September 30 - October 3, Dubna, Russia A. Drutskoy, ITEP Cosmic veto system basic setup for Phase-I Dubna, Sep 30- Oct 3 1
Cosmic veto activity ITEP (Moscow) group M. Danilov, A. Drutskoy, O. Markin, V. Rusinov, E. Tarkovsky BINP (Novosibirsk) group G.Fedotovich, D.Grigoriev, A.Ryzhenenkov, D.Shemyakin
Cosmic veto configuration Cosmicvetosystem forPhase-I (4100) 4400 4200 2000 Size of strip (can be no longer that 3m): 220 cm x 4 cm x 0.7 cm (on top) Size of module (15 strips) : 220 cm x 60 cm x 0.7 cm (~ 10 kg) Supermodules: 2 on top, 4 on backsides (half size), 1 in front and 1 rear 4 layers of strips to provide background suppression better than ~10-4
Cosmic veto configuration 4400 (4100) 4200 Supermodule 2000 Strips are glued on polystyrene plate and are moved in support (next talk)
Strips and SiPMs 2200 SiPM Amplifier chip Strip 0.7 x 4 x 220 cm3 is made of polystyrene base scintillator by “Uniplast” (Russia) with 1.2 mm diameter WLS fiber in center groove andwith mated surface which provides diffuse reflection of light. The fiber is glued into the groove with a special gel and equippedby SiPM.
ITEP group COMET group in ITEP includes 5 members: Michael Danilov – basic geometry Alexey Drutskoy – TDR text, simulations Oleg Markin – MC simulation Vladimir Rusinov – hardware EvguenyTarkovsky – hardware, SiPM Proposed technology is almost the same as one planned for Belle II muon system. Currently mass production for Belle II muon system is going on and will be finished at the middle of 2014. We plan to use this working infrastructure just after Belle II mass production will be finished. Whole volume of COMET veto system production work is about 10% of Belle II muon system production. ITEP has required resources: workshop, rooms,strip test facilities.
Cosmic muon backgrounds in Phase-I m- SyDet m+ Muon decays in flight or muon interactions in material with final electron produced. e+ e- In Phase-I configuration cosmic muon background can be due to positrons produced in SyDet wall, or electrons produced in Muon Stopping Target. In second case we will see muon track in SyDet.
MC simulation of cosmic muons cos2q After 3.5 m concrete Factor ~3-4 cosq P(m), GeV/c P(m), GeV/c Energy loss in concrete: approximately 4MeV/cm Cosmic muons, which can produce “signal-like” background, mostly have small momentum (<1.5 GeV/c) and small azimuth angle (cosq > 0.5)
MC simulation issues MC simulation of cosmic muon momentum and angular distributions (has been partially done, has to be adapted to Phase-I configuration). MC simulation with detailed geometrical model of strip efficiency, module and supermodule positioning (10-4 inefficiency to be reached). Oleg Markin is working now for this issue. Test of “one strip signal” and “two layers strip coincidence”. Dead time due to noise and inefficiency for both cases has to be obtained. Detailed modeling of SyDet and other components (COMET MC). Modeling of Cosmic Veto trigger (for SyDet calibration).
Price list Scintillator: 4 x (420 x 440 x 0.7 + 2 x 420 x 200 x 0.7 + 2 x 410 x 200 x 5/6 x 0.7 ) = = 1370508 cm3 = ~1370 kg = ~ 41,000 $ +10% (1000 cm3 ~ 1kg ~ 30$) Fibers (WLS): 1370508/(100x4x0.7)=4895m = ~ 44,000 $ + 5,000 $ shipping (1m ~ 9$) SiPM (Hamamatsu Photonic): 4895 / 2 = 2450 units = ~ 49,000 $ +5% (if Japan buys) (1 SiPM ~ 20$) 4. Preamplifiers: 2450 units = ~ 7,500 $ (ITEP, 1 PA ~ 3$) 5. Support, polystyrene, optical gel, other materials : ~ 15,000 $ SUM ~ 200,000 $ Electronics – we have no possibility to make electronics. Generally we expect that Belle II muon system electronics can be taken.
Time schedule Scintillator production rate : ~ 30 kg /day => ~ 50 days. Strip and module production – about the same speed. To start production we must obtain WLS fibers from Japan (timing?) Modules can be produced in ITEP and shipped in J-PARC. Shipping costs (~10,000 $) ? It depends on intergovernment agreement. Was it signed recently? We need agreement between J-PARC (KEK) and ITEP (Kurchatov center). Support can be assembled in J-PARC and modules can be moved in. Manpower to assemble and maintain the veto system by ITEP people. How much money we need for? Mass production has to be finished by the end of 2014.
Strip counters construction ITEP production (Moscow) • Every counter has dimensions : 7х40х1000мм³ • The light signal is read-out on both sides with twoSiPM (Japan) • SiPMsensitive area is 1.3×1.3 мм² • Long time test (stability study) ~ half year
Four counters were tested in real condition with CMD-3 at VEPP-2000
Stand to measure counter parameters with cmd-3 digitizing electronics (16 channels) Discrimina tor Аmplit. T2Q, Тrigger
Time resolution with cosmic rays (preliminary)
Conclusion 1. Cosmic veto system should provide background suppression on the level of 104. Rough estimates show that proposed system can provide such suppression. Detailed MC has to be done. 2. Trigger with cosmic veto system should be studied in detail. We need to discuss who can help with electronics for cosmic veto. Sources of financial support have to be finally arranged and fixed.
