SLIDE 1
Masashi Y
- koyama Kyoto
Nov.10 NBI03 @ KEK
K2K Near Detector 2 SciBar Detector Masashi Y okoyama Kyoto Nov.10 - - PowerPoint PPT Presentation
K2K Near Detector 2 SciBar Detector Masashi Y okoyama Kyoto Nov.10 - - PowerPoint PPT Presentation
K2K Near Detector 2 SciBar Detector Masashi Y okoyama Kyoto Nov.10 NBI03 @ KEK Introduction Motivation Events K2K result indicates 12 m 2 2.8x10 3 10 for oscillation 8 Oscillation maximum at 6 E
SLIDE 2
SLIDE 3
K2K result indicates ∆m2≈2.8x10–3 for νµ ↔ντ oscillation Oscillation maximum at Eν≈0.6GeV for 250km of baseline Study of neutrino interaction at low energy is important to maximize sensitivity
2 4 6 8 10 12 1 2 3 4 5 Eνrec Events
Motivation
⇒Construct new detector
SLIDE 4
Clean reconstruction of vertex High efficiency for all particles Low momentum threshold for tracks (esp. protons) Full active detector Fine segmentation µ/p/π separation Range+dE/dx EM calorimetry for study of νe/π0
Requirements
SLIDE 5
Detector Water Cherenkov 1kt ν beam
To Super-Kamiokande
SciFi/Water target
SciBar detector
Muon chamber K2K Front Detector
Full-active tracker with Scintillator Bars!!
SLIDE 6
Detector design
SLIDE 7
3x3x1.8m3 (Tot. mass ~15t) ~300 interactions/day, ~40,000 int./3x1019 POT expected if fid. mass=10t Full active, fine grained 1.3x2.5cm2, 64 layers High efficiency for all particles from vertex Threshold for protons ~350MeV e/π0 ID capability w/ EM calorimeter
SciBar detector overview
⇒Precise study of ν interaction!
SLIDE 8
Scintillator 2.5x1.3x300cm3 MINOS-type extruded scintillator (made at FNAL) 64 layers (X+Y) 14336 channels in total Wave length shifting fiber 1.5mmΦ x 360mm Kuraray Y11 Attenuation length: ~360cm (all fibers measured before installation) Light yield: 20p.e./cm for MIP after 40cm of fiber
Scintillator and fiber
SLIDE 9
Hamamatsu H8804 64ch w/ 2x2mm2 pixel size Alignment w/ fiber better than 300µm Cross-talk to adjacent channel: ≤3% All channels calibrated before installation Gain~5x105
Multi-Anode PMT
Fibers w/ cookie after polishing
SLIDE 10
Readout electronics
VA/TA VA/TA 64ch MA-PMT
Frontend Board (FEB)
VA/TA& timing Controller VME-IF
DAQ Board
FADC FADC FADC FADC FADC FADC FADC FADC x224 x28 FADC FADC FADC FADC FADC FADC FADC FIFO
TDC (64ch) Trigger module
Timing Distributor
VME-bus
VME-PCI BRIDGE
spill info
Linux PC
Large number of channels (~15,000) VA frontend LSI: Multiplex analog signal Readout 64ch with a signal line Low noise: ~0.3p.e. (MIP=10-20p.e.) Large dynamic range Linear up to 300p.e. low energy proton Fast trigger/timing signal TA LSI chip at frontend 32-ch ORed output
SLIDE 11
Modules from CHORUS “spaghetti” calorimeter 1mm diameter fibers in the grooves of lead foils 4x4cm2 cell read out from both ends 30 horiz. + 32 vert. modules (11X0) placed just downstream
- f SciBar main detector
Expected resolution: 14%√E Linearity: better than 10%
4 cm 8 cm 262 cm Readout Cell ν Beam
Electron Catcher
ν beam
SLIDE 12
Photo Gallery
SLIDE 13
Main SciBar E-catcher
SLIDE 14
WLS fibers PMT (backside) VA/TA chip
SLIDE 15
Just Completed!
- Aug. 22, 2003
SLIDE 16
Data taking started on Oct.7...
20 40 60 80
time(µs) 2.0 –0.5 1.0 0.5 1.5 Events (arb. unit)
ID Entries Mean RMS 8220 3092 19.07 8.641 50 100 150 200 250 300 350 400
100 20 40 80 60 p.e./cm Arbitrary unit
Light yield for MIP (Cosmic-ray µ) @40cm from PMT Timing of first hit in beam event after tracking
Extensive calibration work
- ngoing
Gain, timing, alignment... Software development (traking, MC simulation tuning) started So far, SciBar looks working as expected (=excellent performance!!)
1 2 34 5 6 7 8 9
Preliminary
SLIDE 17
Event Gallery
SLIDE 18
Neutrino event (1)
ADC TDC (in-time)
Top view Side view
ν beam
MRD MRD
SLIDE 19
Top view
Neutrino event (2)
Side view
ADC TDC (in-time) ν beam
SLIDE 20
Neutrino event (3)
vertex!
Top view Side view
NC pi0 cand.
SLIDE 21
E-catcher E-catcher
Neutrino event(4)
Top view Side view νe candidate
SLIDE 22
SciBar is Full-active (15t total volume) Fine-grained (1.3x2.5cm) detector for precise studies of ν interaction Stably working for one month, data quality looks excellent Still lots of work (and fun) to be done, but making rapid progress towards physics results
Summary
SLIDE 23
Backup Slides
SLIDE 24
Extruded Scintillator
- Mix poly-stylene with PPO 1%, POPOP 0.3%
– Maximum of emission spectrum : 420nm
- 1.3 x 2.6 x 300 cm3
- 1.8mm diameter hole at the center
- TiO2 coating (t0.25mm)
– As a reflector – Extruded together
2.5cm 1.3cm 300cm
Light yield uniformity <5%
SLIDE 25
Wavelength Shifting Fiber
Scintillation Secondary emission Charged particle 400 500 600
- Kuraray
Y11(200)MS 1.5mm diam.
- Attenuation length : 3.6m
- Absorption peak
– 430nm
- Emission peak
– 476nm
SLIDE 26
Gain monitoring w/ LED
(4) (56×4)
SLIDE 27
2022 2024 2026 2028 2030 2032 2034 2036 2038 2040 5020 5040 5060 5080 5100 5120 5140 5160 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 5020 5040 5060 5080 5100 5120 5140 5160
Pedestal(Main Part) Page1
view0:layer0:strip0
run pedestal(count)
view0:layer0:strip1
run pedestal(count)
SLIDE 28
0.145 0.15 0.155 0.16 0.165 0.17 5020 5040 5060 5080 5100 5120 5140 view1:layer8:strip46
run Gain(ADC/PIN)
+2%
- 2%
Stability of gain
SLIDE 29
VA/TA readout chip
multiplexer sample&hold slow shaper preamp. fast shaper discri.
CH1 CH2 CH32
VA serial output TA (32ch OR)
（energy information） （trigger, timing information）
~1µs
SLIDE 30
Proton ID w/ dE/dx
Proton
Beam test w/ prototype, 1 cell only p (GeV/c) p.e./layer p/pi separation w/ <10% mis-ID below 1.2GeV/c possible by more sampling points
SLIDE 31