HCAL-J Update (G.B. Franklin, CMU, Mar. 2015) 40 Ton Detector 288 modules Arranged in 4 sub-assemblies 24 Modules (360 cm) 12 Modules (180 cm) 1 Absorbers Scintillators Wavelength Shifter PMT Rectangular to cylindrical Light Guide Today’s Talk 1)New Cosmic-Ray Timing Tests (Proto4) 2)New light-guide details 3)December engineering review 4)Status of production

2 1)Cosmic Ray Timing Measurements First: A Brief Historical Note Proto2 results shown at the Nov. DOE Review showed 340 ps timing resolution (cosmics) Predicted TOF better than 300 ps rms with improved light guides

3 Proto4 Cosmic Tests (Proto3 assembled and sent to JLab for Hall A tests) Improved light guide More than x2 photoelectrons 277 ps rms time resolution (after start-time resolution correction) Vahe Mamyan’s measurements show we have exceeded our expected time resolution for cosmics 400 photo-electrons at peak Integrated Raw FADC Units Time – Start Time (nsec)

4 Updated Monte Carlo Results Vahe used Proto4 results to tune Monte Carlo Result: 0.7 ns rms time resolution for 4.8 GeV/c neutrons (No change for 2.7 or 8.8 GeV/c simulations) Simulated HCAL-J timing resolution for 4.8 GeV/c neutrons

5 2) Light Guide Details Bracket and Optical Fiber Guide Tube Mounting Holes Guide Tube Hole Gluing Holes Fishing Line Anchors Laser-cut Acrylic Light Guide Bracket Bracket Solvent-Welded to Cylinder Bracket Bolted to End Cap Guide Tube Proto4 Back End Cap Detail Guide Tube Light Guide Aluminized Mylar Bracket

6 3) December Engineering Review Review of Sub-Assembly concept and details of HCAL-J Module to Subassembly connection Conceptual design document submitted by CMU Attended by: JLab: Mark Jones, Robin Wines, Whit Seay, Alan Gavalya CMU: Gregg Franklin, Vahe Mamyan, Alexa Johnson 2 nd Day follow-up meeting discussed small design change in HCAL-J front plate JLab will take over engineering of the support structures for the 4 sub-assemblies this summer

7 4) Status of Production Light Guide Production Laser Cutting 90 seconds each Bending Jig Radiant Heater Gluing Jig Solvent Welding Need to remember to take a photo of this Diamond Fly-cutting Oxy-hydrogen Flame Polishing

8 Light Guide Production Status 11 Completed and glued to WLS 30 more assembled- awaiting final milling and gluing WLS Components for ~20 more in queue for gluing Summary: Will soon have 50 completed light guides with many more parts already in queue for machining and bending

9 Production Status Summary Proto3 and Proto4 could be considered first two modules Absorbers and scintillators ready for installation Purchased and received vacuum screws, plastic PMT adapters, etc. VersaFab Machine Works producing 300 sheet-metal cans, 600 internal shims, 1800 “ribs” Will deliver 33% at a time 2 weeks late on first shipment, but any day now… Awaiting delivery of custom-width aluminized Mylar Activities At CMU 300 Steel Front End Plates and 300 Al. Back End Plates All 600 have been cut to size 40 each are being finalized (machined, drilled, tapped) ~ 50 Light guides and WLS ready Expect to assemble~ 2 modules per day once cans are delivered First shipment to JLab early summer (60 modules at a time) Must clear space as we assemble

10 Milestone Review Detailed design Completed: June 2014 (+ 2 months float) DONE Design review: (Sept. 2014) (+3 months float) Scope to include sub-assembly concept. Dec DONE Module construction initiated: Oct 2014 (+4 months float) First two modules of finalized design under construction Large scale assembly awaits rib and shell order completion Will start Jan./Feb. NOW BEHIND (unless Proto3 and Proto4 counts or assembly of light guides counts) Module assembly 50% completed: March, 2015 (+4 months float) APPEARS THAT WE WILL BEAT THIS Construction completed: Sept (+9 months float)