1. The Beam Test at Fermilab:
W.Baldini for the IFR group
SuperB I-st coll. Meeting, QMUL London Sept

2. The Prototype Iron Prototype
Active Layers
(Pizza Boxes)
Iron
Prototype
Iron: 60x60x92 cm3, 9 slots for the active layers
up to 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
Active Layer
(“pizza box”)

3. The beam tests
We took data on beam on Dec 2010, mainly at high momentum (8,6,4 GeV)
Prototype shipped back to Ferrara and taken cosmics data (efficiency confirmed, SiPM high temperature problem showed up)
Setup optimized (DAQ, SiPM gain correction with temperature, ODC fully exploited and improved…)
July-Aug new test beam with the improved setup
Extend data taking down to 1 GeV with also TOF information and a heavier gas in the Cherenkov (C4F8O)
Unfortunately, due to the bad weather, we got only about 50% of the expected beam time….

4. The July beam test at Fermilab
The prototype
The July beam test at Fermilab
The FBTF
Photos by R.Malaguti

5. The Fermilab Test Beam Facility
Meson Area
Beams extracted
From Main Injector
The FBTF control room
W. Baldini, Ferrara INFN

6. Testbeam Setup Muon tracks Pion tracks Mu + Pi tracks Min Bias
IFR detector prototype
beam
Cherenkov
15 cm of
Iron
S3, S4 (scintillators):
all layers hit
S1, S2
Charged
track
Not an
electron
S1x S2
Triggers:
Muon tracks Cm
Pion tracks
Mu + Pi tracks Ce
Timing
Min Bias

7. Summary of data taking Installation and setting up: July 13-19
Security walkthrough: July 19, first beam: July 20
Data taken with N2 gas in the Cherenkov :
Tue 26 – Sun 31 No Beam due to T-storm
C4F8O in the Cherenkov, data taken (sum of all triggers):
Aug 2-nd no beam after 4 p.m. (supposed to have beam until 6 a.m.)
Expected beam: 168h provided: 89h of which 17h at the wrong energy (4 GeV instead of 2 )  53% (-10% wrong energy)
8 GeV
6 GeV
4 GeV
2 GeV
1 GeV
Triggered (all trig.)
215k
217k
820k
Wrong energy!
398k
8 GeV
6 GeV
4 GeV
2 GeV
1 GeV
Triggered (all trig.)
69k --
130k
221k

8. Summary data taking (II)
(Hz)
Jul 26 0:00
NO BEAM
Jul 31 22:45
NO BEAM

9. Cherenkov pressure Scans:
We used 2 gases: N2 and C4F8O
We performed a pressure scan for each beam momentum
Expected pressure thresholds:
8 GeV
6 GeV
4 GeV
2 GeV
1 GeV
mu-thres (psi)
4.3
7.6
17.2
68.6
275
Pi-thres (psi)
7.5
13.3
30.0
120
478 N2
8 GeV
6 GeV
4 GeV
2 GeV
1 GeV
mu-thres (psi)
0.92
1.64
3.69
14.8
58.7
Pi-thres (psi)
1.61
2.86
6.44
25.7 *
103
C4F8O
* Max allowed pressure in the Cherenkov vessel: 22 psi

10. Cherenkov pressure scan: 8 GeV - N2
Pions
Ratio between muon trigger and beam counter rate vs pressure in the Cherenkov
(cher1xS1xS2) counts/ beam counts
Expected pion
thres.: 7.5 psi
Expected muon
thres.: 4.3 psi
Muons
N2 Pressure (psi)

11. Cherenkov pressure scan: 6 GeV – N2
Exp. Muon
thres. : 7.7 psi
Exp. Muon thres.: 13.4 psi
Normalized Cherenkov counts
Muon “peak”
Normalized S1xS2xC1 counts

12. Cherenkov pressure scan: 4 GeV – N2
Expected Muon
thres: psi
Normalized Cherenkov counts
Normalized S1xS2xC1 counts

13. Cherenkov pressure scan: 4 GeV – C4F8O
mu threshold
Expected
pi threshold
Expected

14. Temperature
In order to keep the temperature of the SiPMs under 25 °C we had to cover the prototype with a “tent” and cool down the volume with 2 portable air conditioners
Average temperature
(measured at the 4
“corners”)
Temperature
spread

15. Time Of Flight Detector
Expected mu-pi time difference (assuming ~20m distance):
- 1 GeV : ~ 230 ps
- 2 GeV: ~ 60 ps
- 3 GeV ~ 13 ps
- TOF exp. Resolution: 30 ps

16. Time Of Flight Small radius  low rate at low momentum (broad beam)
No big differences from 1 to 6 GeV
Proton signal is clearly visible but pions and muons are probably hidden by some “instrumental effects”
Small radius  low rate at low momentum (broad beam)
More details in Gigi’s talk
1 GeV
2 GeV
protons
4 GeV
6 GeV
protons

17. Light Yield Measurement
1 p.e.
Scintillator thickness: 2 cm
Fiber: Saint-Gobain 1.0mm, L= 45cm
SiPM: 1.2x3.2 mm2 (4020)
2 p.e.
Np.e. ≈ 15
Dark counts
Signal on beam

18. Conclusions and next steps (I)
The R&D activities were focused primarily on the test beam of the prototype (Jul.-Aug), on the analysis of the data and on the related MC simulations
Our setup (detector, FE electronics, DAQ, ODC…) worked very well, after the optimization performed with cosmics in Ferrara
The TOF (and the MWPC) was easily integrated in our data taking system
But……
Only part of scheduled measurements could be completed due to many problems with the beam (no beam for ~50% of the expected run time and 10% at the wrong energy)

19. Conclusions and next steps (II)
We are planning a new beam test (1 week) in October to complete the program
More data at low momentum: 4,3,2 GeV
Data analysis is ongoing (see next talks) to study the detector performances (efficiency, time resolution) and the mu-ID capability
A new data taking is foreseen in Feb.– Mar to test a possible BIRO configuration for the Barrel
Fix the BIRO-Barrel design (many ideas & discussions, need to converge to a layout)
Irradiation tests of electronics, SiPMs etc… study of performance degradation (gain, dark current, dark noise) vs dose, with/without absorbers/shieldings
Study of a cooling system for the SiPMs on the detector