Detector with Plastic Scintillators Dong Hee Kim Kyungpook

Detector with Plastic Scintillators Dong. Hee Kim Kyungpook National University International Workshop on a Far Detector in Korea 1 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Contents 1. Extruded Plastic Scintillator 2. Current R&D Status 3. Summary of R & D so far 4. Application to Far Detector 5. Summary & Conclusion International Workshop on a Far Detector in Korea 2 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Extruded Scintillator • Comparing with Casting method: ü Use commercial polystyrene pellets → Cheap ! ü Processing flexibility → Manufacture of essentially any shape with reflector. • Experimental applications: ü ü ü MINOS for two detectors: 300 ton of scintillator strips D 0 for two preshower detectors Star for a shower max. detector in the em. end-cap calorimeter MINERVA K 2 K – Sci. Bar detector And more …many applications for your future detectors International Workshop on a Far Detector in Korea 3 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Extruded Plastic Scintillator Ø Component: Polystyrene pellets + Dopants (primary & secondary) Ø Dopants • Primary dopants (UV-emitting) PPO(2, 5 -biphenyloxazole) , PT(p-Teraphenyl) 1 -1. 5% (by weight) concentration • Secondary dopants (blue-emitting) POPOP(1, 4 -bis(5 -Phenyloxazole-2 -yl)benzene), bis-MSB(4 -bis(2 -Methylstyryl)benzene) 0. 01 -0. 03% (by weight) concentration International Workshop on a Far Detector in Korea 4 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Plastic Scintillator – how does it work ? Excitation of base plastic by radiation 10 -8 m Faster energy transfer Emit UV ~340 nm 10 -4 m Base plastic PPO (~1%) photon Absorb UV photon POPOP(~0. 05%) Emit blue ~400 nm photon Use WLS fibers as readout Detector (PMT, photo diode …. ) International Workshop on a Far Detector in Korea 5 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Ø Ø Die profile Die and Materials Mixture of dopants Polystyrene : 100% PPO : from 1. 0 % POPOP : from 0. 03% • This was originally for MINOS tile • We start to produce this tile for a reference • produce and compare the light yield with reference tile International Workshop on a Far Detector in Korea 6 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Extrusion Process Produced at Mi. Sung Chem. co. In Korea International Workshop on a Far Detector in Korea 7 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Current R&D Status Ø The pure polystyrene bar was produced (w/o PPO, POPOP) The mechanical process has been established and choose the best polystyrene Ø PPO and POPOP were mixed up with polystyrene The 1 st scintillator had been produced. Ø Many scintillator strips have been produced with different situations since then. different amount of PPO and POPOP, nitrogen and/or vacuum, various mix-up methods etc. International Workshop on a Far Detector in Korea 8 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Mechanical establishment of tile Ø Produce polystyrene bar without PPO & POPOP for mechanical establishment Ø Ti. O 2 was co-extruded to make reflector for test. Ø Excellent bars were produced assure mechanically Ø Then, 1 st batch came with PPO and POPOP. Progress International Workshop on a Far Detector in Korea 9 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Production of Scintillator bar International Workshop on a Far Detector in Korea 10 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Comparison of transparency Oxidation made the sample opaque because of production in air. Reference samples Polystyrene (only) bar 1 st batch Recent batch Progress International Workshop on a Far Detector in Korea 11 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Preparation of test samples WLS fiber International Workshop on a Far Detector in Korea 12 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Scintillator test setup Ø 5 reference samples and new samples with the same geometrical shape and size were used to compare the light yield FAN IN-OUT Disc Logic unit Gate Generator 100 ns Delay Typical cosmic ray From reference sample + WLS VME readout International Workshop on a Far Detector in Korea 13 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Polystyrene only Ø products of LG and Dongbu chemical company Ø totally about 10 polystyrenes tested Ø chose LG 25 E Ø (the best attenuation length etc. . ) International Workshop on a Far Detector in Korea 14 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Pulse Height (1 st batch) Our sample(1 st batch) Our scintillator bars (5 samples) <ADC counts> = 225. 9 24. 9 Reference scintillator bars(5 samples) <ADC counts> = 534. 8 56. 9 ADC counts Reference sample Relative Light Yield of the first samples shows 42. 3% of reference samples ADC counts International Workshop on a Far Detector in Korea 15 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Light Yield Relative Light Yield Reference tile to be 100% light yield Progress International Workshop on a Far Detector in Korea 16 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Light Yield (currently the best one) Reference Sample New Sample Relative Light Yield of new samples shows (93± 8)% of reference samples’ one. International Workshop on a Far Detector in Korea 17 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Position Scan across the fiber International Workshop on a Far Detector in Korea 18 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Summary of R & D so far Ø First Polystyrene bar produced with PPO and POPOP The mechanical process has been established Ø Light yield measured for new and reference samples Currently the best samples show (93± 8) % light yield Ø Of course, need much more R & D in the future improving attenuation length, light yield, uniformity and radiation hardness etc. . Fiber(WLS and clear) will be also R & Ded in the Misung company Ø We can apply this to the detectors The LHC and LC … calorimeters Neutrino LB Experiments Reactor experiments etc…. International Workshop on a Far Detector in Korea 19 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Application to the Far Detector • For appearance experiment ü Totally active is appropriate • Nova already chose liquid scintillator option • Here we consider the plastic scintillator option • Reference from Nova proposal – Thanks for them! • Nova adopted Liquid scintillator option International Workshop on a Far Detector in Korea 20 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Application to the Far Detector Total Plastic Scintillator Calorimeter 120 m • • • all active absorber 300 X 0 depth ~ 2000 Layers 15 m each layer : 15 m x 15 m 27 k. T plastic scintillator one bar : 6 cm x 15 m 250 bars/layer x-y positioning every other layer Total ~ 500 k channels 6 cm 15 m International Workshop on a Far Detector in Korea 21 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Scintillator Bar • Polystyrene + PPO + POPOP • 2 mm WLS Fiber embedded in the bar • Light Reflector(Ti. O 2) • readout both ends by APD(or Si. PM? ? ) • need about 1 M APDs • Ensure enough light yields • with 2 mm WLS fiber (4 time better light collection compared with 1 mm fiber) and Both end readout International Workshop on a Far Detector in Korea 22 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Cost Estimates 1. Scintillator & Fiber : $ 87 M 2. Electronics and DAQ : $ 8 M 3. Building & outfitting etc. . : $20 M 4. Total cost : ~ $114 M item Polystyrene PPO POPOP total weight (kg) cost($) 26721900 43554391 270000 38830297 8100 5280920 Ti. O 2 and fiber etc Very rough estimates • Need more studies • sum ~ 27 k. T Scintillator costs ~ 87 M International Workshop on a Far Detector in Korea 23 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Summary Ø will start R & D for this far detector ØPlastic scintillator option may also be feasible Ø scintillator R & D will go on as it scheduled International Workshop on a Far Detector in Korea 24 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Backup International Workshop on a Far Detector in Korea 25 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05

Application to the Far Detector Option B : Sampling Calorimeter • • • Scintillator/Fe Sandwitch 300 X 0 depth ~ 230 Layers each layer : 15 m x 15 m Iron 15 m x 2 cm Iron 2 cm = 1. 14 X 0 8 k. T iron 3. 1 k. T plastic scintillator one strip: 6 cm x 15 m 250 strips/layer x-y positioning every other layer ~20 m 2 cm thick Fe Scintillator Bar 15 m International Workshop on a Far Detector in Korea 26 for the. J-PARC Neutrino Beam, KIAS, Nov 18 -19, ‘ 05