Barrel Calorimeter Status Quo

1
Barrel Calorimeter Status Quo

• Zisis Papandreou
• University of Regina
• GlueX Collaboration Meeting
• JLab, December 11-13, 2003

2
Outline

• BCAL Module Prototyping
• 2-m Module-0 Construction Tests
• 4-m Module-1 Preparations
• BCAL Readout RD
• HPD Review
• SiPM Test Results

3
2-m Module-0

• Great crew of undergraduates
• Construction Completed
• 200cm (l) x 13cm (w) x 17cm (t)
• 180kg
• Polishing Completed
• Preliminary Tests with Cosmics

4
Module-0 The Matrix

• Construction method
• Tricks, Dos and donts
• Method is under control
• Minor RD required for 4-m Module-1

5
2-m Gluing Pressing Process
All that glue for GlueX.
6
Trickery rewards
Vaseline to the rescue
7
The Ruler Test
8
When you least expect it
Big Brother is watching!
9
Matrix Reloaded

• 2-m testing with cosmics and beam (Serpukov/Hall
  B?)
• 1-m prototype with Scintillator sheets (IU).
• 4-m prototype construction at CSR/UofA
• MOU with UofA signed.
• Softer Pb received (Vulcan), Epoxy (Bicron)
• 100-km fibers arrived snag in shipment
• 4.5-m press, Cutting, Spooling Design
• Preparations at UofA are underway for 4m work
• Timetable completion August 2004?

10
Pure Leadnow
Now thats a toilet paper roll!
11
BananaProblemis solved
12
Lead Cutter

• - 2m prototype
• 4m next
• multiple track

13
Spooling RD
Hair salon? Combs nonetheless!
14
Cosmic Tests (Vitaly Kovaltchouk)
15
ADC Spectra
PRELIMINARY
16
TDC Spectra
??550 ps
??670 ps
PRELIMINARY
17
And what about the readout?

• 2 Tesla field field gradient
• Compact design cost considerations
• Technology
• Hybrid Photo Diode Review
• Silicon Photo Multiplier New Tests
• Multi Channel Plates?
• Avalanche Photo Diodes?

18
HPD Measurements (Vitaly Kovaltchouk, Keith
Wolbaum, Garth Huber)

• HPD gain is 1600 preamp, amp-shaper needed
• Noise Setup is sensitive but under control
• Light sources
• Xe-N flasher its RF interfers requires
  shielding
• NaI crystal and 241Am, 137Cs and 60Co sources
• LED (pulsed) neutral density filter, fiber
  lightguide
• Measurements HPD PP0350G with Multi-Channel
  Analyzer (Tektronix 5200)
• Bottom line system works, rise time poor, energy
  resolution modest, components are expensive

19
Compact but expensive
2001
20
Pre-amp and board
21
Rise Time vs. External Capacitor

• Light Source Nanosecond Broad-Spectrum Optical
  Pulse Radiator (Model NR-1A) and Laser Pulse
  Simulator (Model LPS-1A), HV 20 kV.
• HPMT A 25 mm proximity focused single pixel
  Hybrid Photo Diode equipped, with an S20UV
  photo-cathode on a quartz input window, HV 8 kV,
  Bias 75 V. Silicon diode capacitance 200 pF.

Tube Type Cexternal (pF) Rise Time (ns) Amplitude (mV) MCA Channel Noise (mV)
DEP 350G 22000 150 1300 950 3
10000 150 1400 1100 3
200 100 600 500 3
100 55 400 310 3
50 40 250 210 3
25 35 120 100 3
Burle 8875 0 lt10 8000 - 2
22
MCA Spectrum (LED)
LED off
LED on
23
241Am Spectrum
13 energy resolution
Vitaly Kovaltchouk
24
SiPM a new Sheriff in town

• Multi pixel silicon photo diode
• Micro pixels (20-30?m) on common load
• 500 pixels in 1mm2 area
• Operates in Geiger mode 106 gain
• Provided by Moscow Engineering and Physics
  Institute

25
HPD vs. PMT
26
SiPM vs. PMT
Optitron Xe-N Plasma Discharge Tube
27
Timing resolution
SiPM
PMT
140 ps
375 ps
28
Energy resolution
Xe-N Lecroy 612A
90Sr on Scintillating Fiber
1 pe
Low light
Scint Light
2 pe
signal
3 pe
noise
29
SiPM in a nutshell

• Very promising readout for BCAL
• Better timing and energy resolution than standard
  2 PMTs
• 50 prototypes, 1 for bulk orders?
• Tests to come
• Couple to Module-0 and measure
• Test in high magnetic field (MRI?)
• Radiation hardness
• Geometrical packing (Winston cones, wavelength
  shifters ? funnel light down)

30
So, where are we?

• Matrix construction is well in hand
• 2-m test cosmic results available soon
• 4-m will have modest RD obstacles
• Construction site (UofR, UofA)
• Readout type may have been found
• SiPM very suitable (MCP, APD?)
• Frame and integration issues outstanding