The new-generation high-granularity Shashlyk EM calorimeter readout by micropixel avalanche photodiodes (MAPD) with precision thermostabilization based on the Peltier element is designed, constructed ...end tested. MAPD-3N with superhigh pixel density 1.5×104mm−2 and area 3×3mm2 manufactured by the Zecotek Company were used in the photodetector unit.
Novel micropixel avalanche photodiodes (MAPD) with super high pixel density Anfimov, N.; Chirikov-Zorin, I.; Dovlatov, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2011, Letnik:
628, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In many detectors based on scintillators the photomultiplier tubes (PMTs) are used as photodetectors. At present photodiodes are finding wide application. Solid state photodetectors allow operation ...in strong magnetic fields that are often present in applications, e.g. some calorimeters operating near magnets, combined PET and MRT, etc. The photon detection efficiency (PDE) of photodiodes may reach values a few times higher than that of PMTs. Also, they are rigid, compact and have relatively low operating voltage. In the last few years Micropixel Avalanche PhotoDiodes (MAPD) have been developed and started to be used. The MAPD combines a lot of advantages of semiconductor photodetectors and has a high gain, which is close to that of the PMT. Yet, they have some disadvantages, and one of them is a limited dynamic range that corresponds to a total number of pixels. The novel deep microwell MAPD with high pixel density produced by the Zecotek Company partially avoids this disadvantage. In this paper characteristics of these photodetectors are presented in comparison with the PMT characteristics. The results refer to measurements of the gain, PDE, cross-talks, photon counting and applications: beam test results of two different “Shashlyk” EM calorimeters for COMPASS (CERN) and NICA-MPD (JINR) with the MAPD readout and a possibility of using the MAPD in PET.
The main properties of two different Shashlyk EM calorimeter modules readout by novel micropixel avalanche photodiodes (MAPD) with microwell structure and very high density of pixels were studied at ...the T9 CERN PS test-beam facility. A MAPD-3A with density of pixels 1.5×10
4
mm
−2 and area 3×3
mm
2 manufactured by Zecotek Company was used in our test.
The matrix of 3 × 3 modules of the EM calorimeter ECAL0 (COMPASSII) read out by MPPCS12572-010PSiPMs with the pixel density of 104 mm−2 and an area of 3 × 3 mm2 is studied in the range of electron ...energies 1–30GeV. It is observed that the MPPC has additional response nonlinearity and a significantly smaller dynamic range of output signals than expected. The influence of parasitic capacitance between pixels on the pixel gain is discussed and proposed as explanation. The energy resolution of the calorimeter is measured to be σE∕E=7.1%(1+0.06∕E)∕E⨁1.4%E0.25, where electron energy E is given in GeV.
•New-generation shashlyk calorimeter read out by SiPMs is studied with test beams.•High-pixel-density SiPM MPPC S12572-10 has additional response nonlinearity.•Influence of parasitic capacitance between pixels on the pixel gain is discussed.•Energy resolution of the calorimeter is measured and parameterized.
DISTO data on K − p p Maggiora, M.; Kienle, P.; Suzuki, K. ...
Nuclear physics. A,
04/2010, Letnik:
835, Številka:
1
Journal Article
Recenzirano
The data from the DISTO Collaboration on the exclusive
p
p
→
p
K
+
Λ
production acquired at
T
p
=
2.85
GeV
have been re-analysed in order to search for a deeply bound
K
−
p
p
(
≡
X
)
state, to be ...formed in the binary process
p
p
→
K
+
X
. The
preliminary spectra of the
Δ
M
K
+
missing-mass and of the
M
p
Λ
invariant-mass show, for large transverse-momenta of protons and kaons, a distinct broad peak with a mass
M
X
=
2265
±
2
MeV
/
c
2
and a width
Γ
X
=
118
±
8
MeV
/
c
2
.
Analyzing DISTO data of
pp
→
p
Λ
K
+
at
T
p
= 2.50 and 2.85GeV to populate a previously reported
X
(2265) -resonance with
M
x
= 2267 MeV/c
2
and Γ
x
= 118 MeV at 2.85GeV, we found that the yield of
X
...(2265) at 2.50GeV is much less than that at 2.85GeV (less than 10%), though it is expected from a kinematical consideration to be produced as much as 33% of that at 2.85GeV. The small population of
X
(2265) at 2.50GeV is consistent with the very weak production of Γ(1405) at the same incident energy toward its production threshold, thus indicating that Γ(1405) plays an important role as a doorway state for the formation of
X
(2265).
We have analyzed data of the DISTO experiment on the exclusive
pp
→
K
+
Λ
p
process at
T
p
= 2.85 GeV to search for a
K
−
pp
( ≡
X
) nuclear bound state to be formed in the
pp
→
K
+
+
X
...reaction. The deviation spectra of the
K
+
missing-mass Δ
M
(
K
+
) and Λ
p
invariant-mass
M
(Λ
p
) with selection of large-angle proton emission revealed a structure with
M
X
= 2265 ±2 MeV/
c
2
and
Γ
X
= 118 ±8 MeV.
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