1 Fermi National Accelerator Laboratory EXTRUDED SCINTILLATOR STATUS Anna Pla-Dalmau April 9, 2010

2 EXTRUDED PLASTIC SCINTILLATOR ADVANTAGES: Use commercial polystyrene (PS) pellets -No monomer purification problems Processing flexibility -Manufacture of essentially any shape DISADVANTAGES: Poorer optical quality -Particulate matter in PS pellets -Additives in PS pellets SOLUTION: Use a WLS fiber

3 FNAL-NICADD EXTRUSION FACILITY SINCE 2003

4 FNAL-NICADD EXTRUSION FACILITY In-line continuous process: Less handling of raw materials Precise metering of feeders Twin-screw extruder (better mixing) Melt pump offers steady output Control instrumentation Line under nitrogen atmosphere: Drying under nitrogen Each piece of equipment is purged POLYMER DRYER CONVEYOR POLYMER FEEDER DOPANT FEEDER EXTRUDER MELT PUMP DIE OUTPUT: Scintillating pellets Scintillator bars

5 FNAL-NICADD EXTRUSION FACILITY

6 CO-EXTRUDER PURCHASED IN 2005

7 FNAL/NICADD EXTRUSION FACILITY CO-EXTRUDER CONNECTION

8 EXTRUDED SCINTILLATOR COMPOSITION Blue-emitting extruded plastic scintillator: –DOW Styron 663 W + 1% PPO % POPOP With a 0.25-mm titanium dioxide coating

9 MINERVA SCINTILLATOR DONE 13,850 STRIPS m long DONE 3,020 STRIPS m long

10 OTHER SCINTILLATOR SHAPES 50 mm 10 mm 40 mm 10 mm 1 hole T2K – 40 mm x 10 mm T2K – 50 mm x 10 mm DOUBLE CHOOZ: 50 mm x 10 mm

LESSONS LEARNED 11 T2K – UK: 10 mm x 40 mm good compromise round corners, large hole sharper corners, small hole

12 OTHER SCINTILLATOR SHAPES 45 mm 10 mm 3 grooves JEFFERSON LAB: -CONSIDERED GROOVES AND HOLES FOR THE SAME SIZE STRIP -FINAL CHOICE: -2 HOLES OVER 3 GROOVES PRODUCTION READY TO START

SHAPES TESTED IN R&D 13 5 mm x 100 mm strip: no coating with up to 10 holes solid 10 holes

SHAPES TESTED IN R&D mm x 20 mm strip: white coating 3 holes

15 FUTURE R&D AT THE FNAL/NICADD FACILITY SMALL LAB-SIZE TWIN-SCREW EXTRUDER IN LAB 5: ALUMINUM DIE (5 cm CUBE, SLANTED FRONT) KURARAY FIBER FED FROM THE TOP – NOT IDEAL

16 FUTURE R&D AT THE FNAL/NICADD FACILITY SMALL LAB-SIZE TWIN-SCREW EXTRUDER IN LAB 5: NEW ALUMINUM DIE – MELT COMES OUT AT 90º KURARAY FIBER FED STRAIGHT

17 FUTURE R&D AT THE FNAL/NICADD FACILITY SMALL LAB-SIZE TWIN-SCREW EXTRUDER IN LAB 5: EXTRUDER AND COOLING TANK ARE AT 90º FIBER FEEDER AT THE BACK OF THE DIE

18 Recommendations: –Holes are easier to extrude than grooves –Symmetrical parts are also easier to extrude –Ratio of hole to fiber area does not affect light yield Studies show that a large mismatch between fiber and hole does not lower the overall light yield – tested using a radioactive source –Minimize scrap by setting realistic specifications – this is not a machined part. Observations: –Cost savings – do not glue fiber in the hole EXTRUSION RECOMMENDATIONS

19 MINOS (~300 tons): about $10 / kg –During 2000 – 2002 –All included Recent projects (1-20 tons): about $25 / kg Estimated projection for large quantities: $6 – 7 / kg EXTRUDED SCINTILLATOR: COSTS

20 Early extrusion efforts showed the cost at roughly: –50% materials, 50% processing Current materials cost for a large detector (20 kT): –~ $3 / kg for polystyrene, dopants, reflective coating Dow PS, PPO, POPOP A total of $6 / kg seems possible Processing costs need to decrease: –High extrusion rates, multiple strands, 3 shifts a day, 6 days a week, continuous extrusion (minimize handling) –Minimize QC efforts EXTRUDED SCINTILLATOR: COSTS