1. Status of Prototype Preparation and SiPM Characterization
W. Baldini on behalf of the Ferrara SuperB Group
XIV SuperB General Meeting, Frascati Sept.27 – Oct

2. The IFR Prototype
The Prototype

3. The IFR Prototype The Iron is on Its way to Fermilab Iron
Active Layers
(Pizza Boxes)
The Iron is on Its
way to Fermilab
Iron
Iron: 60x60x92 cm3 , 9 slots for the active layers
8-9 active layers readout together
4 Time readout (TDC-RO) “standard “
4 Binary Readout (BiRo) “standard”
4 special modules to study different
fibers or SiPM geometry

4. Active Layers: the Pizza Boxes
Pizza box #1: TDC-standard (fibers Bicron-1.0mm, SiPM 1.2x3.2 mm )
Pizza box #2: TDC-standard
Pizza box #3: TDC-standard
Pizza box #4: TDC-standard
Pizza box #5: TDC Special fibers 1.2mm
Pizza box #6: TDC Special round SiPM
Pizza box #7: TDC Special MPPC
Pizza box #8: BiRo Standard (fibers Kuraray 1.2mm, SiPM 1.4x3.8 mm )
Pizza box #9: BiRo Standard
Pizza box #10: BiRo Standard
Pizza box #11: BiRo Standard
Pizza box #12: BiRo Special Round SiPM
Menu’
Assembling almost finished: only fibers-SiPM coupling to be done
Waiting to have all the SiPM tested: few weeks hopefully

5. Pizza boxes Assembling Prepare the supports and place
the scintillator bars
Pizza boxes
Assembling
fibers positioning
Put silicone Sealant
to fix fibers and keep optical glue inside the embedded holes

6. Labeling and collecting
the fibers around the supports
Fill the machined grooves
with optical grease and cover
it with stripes of reflecting
aluminum (BiRo only)
Fill with optical glue
the embedded holes
Put double-side adhesive
to fix the second layer
(BiRo only)

7. Aluminum tape
Aluminum on the
not-readout end of
the fibers
Positioning of the second
layer of scintillators (BiRo)
Sputtering
(on 1 pizza box)

8. Next and last step:
Fiber-SiPM coupling
Fibers
SiPM
Output Connector

9. Polishing and Aluminization
With aluminization
No aluminization
The surface of the fiber polished
with the natural diamond mill have
≈ 20% higher “light transmission”
Fiber 1
Diamond mill
finishing
Single fiber
Polishing
machine
The aluminization on the fiber
surface reflects back ≈ 50% of
the light

10. SiPM Characterization

11. SiPM Characterization
three types of SiPM to be tested:
1.2x3.2 mm2 (type 4020), to be coupled to 1.0mm fibers (3 fibers), total 126 needed
1.4x3.8 mm2 (type 4380), for 1.2mm fibers, 128 needed
array of 3 round sensors: f=1.4mm, for both 1.0mm and 1.2 mm fibers, 53 needed

12. SiPM Characterization
Received and tested 98 SiPM:
x3.2 mm2 (4020) :
Good: 23
Bad: 5 (1 no signal, 4 out of position >100mm)
x3.8 mm2 (4380)
Good: 29
Bad: 3 (1 no signal, 2 out of position)
38 round F=1.4 mm (5550) (Analysis ongoing)
Good: 33
Bad: 5 (4 no signal, 1 SiPM out of position)
107 ( , , ) in Perugia now… waiting to be bonded.
In total we need (no spare): , ,

13. SiPM-5550: Gain Distribution @ various Vbias voltages

14. SiPM-5550: Vbias distribution for a fixed Gain
The gain has been chosen as the average of the Gain 33.0V

15. Dark count

16. Selection Criteria Vbias=33V <G> ± 2 σ Good Gain (V/p.e.)
Dark Count (Hz)
<G> ± 2 σ
Good
Gain (V/p.e.)