The data acquisition system of the SuperB-SVT beam test Sbarra, C.; Fabbri, L.; Gabrielli, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2013, Letnik:
718
Journal Article
Recenzirano
Prototypes of a new hybrid pixel detector and a high resistivity detector with short strips, developed by the VIPIX Collaboration and aimed at equipping the layer-0 of the SuperB vertex detector, ...have been tested in September 2011 with a 120GeV pion beam at the SPS H6 beam line at CERN. They are placed at the center of a reference telescope consisting of six planes of silicon detector with a double-sided strip readout. Both the telescope and the detectors under test (DUT) are equipped with a custom-design, data-push digital readout. The main elements of the trigger and data acquisition system are two VME boards (EDRO) organized in a master-slave configuration and responsible for programming the front-end chips of both the telescope and the DUT. The master board distributes a global synchronization clock and the triggers to all devices, including two 3×3 analog-maps matrices placed behind the DUT and supplied with an independent readout. Both EDROs act as event-fragment builders. These are sent out to a remote PC for event building, buffering and storage.
The results obtained by the Slim5 collaboration on a low material budget tracking silicon demonstrator put on a 12
GeV/
c
proton test beam at CERN are reported. Inside a reference telescope, two ...different and innovative detectors were placed for careful tests. The first was a 4k-Pixel Matrix of Deep N Well MAPS, developed in a 130
nm CMOS Technology, square pixels
50
μ
m
wide, thinned down to
100
μ
m
and equipped with a digital sparsified readout running up to 50
MHz. The other was a high resistivity double sided silicon detector,
200
μ
m
thick, with short strips with
50
μ
m
pitch at
45
∘
angle to the detector's edge. The detectors were equipped with dedicated fast readout architectures performing on-chip data sparsification and providing the timing information for the hits. The criteria followed in the design of the pixel sensor and of the pixel readout architecture will be reviewed. Preliminary measurements of the pixel charge collection, track detection efficiencies and resolutions of pixel and strip sensors are discussed.
The data driven architecture of the readout chips has been fully exploited in the test beam by a data acquisition system able to collect on electronic board up to 2.5 Million events per second before triggering. By using a dedicated Associative Memory board, we were able to perform a level 1 trigger system, with minimal latency, identifying cleanly tracks traversing the detectors. System architecture and main performances are shown.
Measurements of the kinematic distributions of
J
/
ψ
mesons produced in
p
–C,
p
–Ti and
p
–W collisions at
in the Feynman-
x
region −0.34<
x
F
<0.14 and for transverse momentum up to
p
T
=5.4 GeV/c ...are presented. The
x
F
and
p
T
dependencies of the nuclear suppression parameter,
α
, are also given. The results are based on 2.4×10
5
J
/
ψ
mesons reconstructed in both the
e
+
e
−
and
μ
+
μ
−
decay channels. The data have been collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The measurement explores the negative region of
x
F
for the first time. The average value of
α
in the measured
x
F
region is 0.981±0.015. The data suggest that the strong nuclear suppression of
J
/
ψ
production previously observed at high
x
F
turns into an enhancement at negative
x
F
.
The S uperB silicon vertex tracker Forti, F.; Avanzini, C.; Batignani, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2011, Letnik:
636, Številka:
1
Journal Article
Recenzirano
The S
uperB asymmetric e
+e
− collider, to be built near the INFN National Frascati Laboratory in Italy, has been designed to deliver a luminosity greater than 10
36
cm
−2
s
−1 with moderate beam ...currents, allowing precision measurements in the flavour sector sensitive to New Physics. The conceptual design of the Silicon Vertex Tracker for the S
uperB Detector is presented, based on double-sided silicon strip detectors for the outer layers, with the addition of an innermost Layer 0 close to the interaction point, with low material budget and capable of sustaining a background rate of several MHz/cm
2.
Deep n-well MAPS in a 130nm CMOS technology: Beam test results Neri, N.; Avanzini, C.; Batignani, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
We report on recent beam test results for the APSEL4D chip, a new deep n-well MAPS prototype with a full in-pixel signal processing chain obtained by exploiting the triple well option of the CMOS ...0.13μm process. The APSEL4D chip consists of a 4096 pixel matrix (32 rows and 128 columns) with 50×50μm2 pixel cell area, with custom readout architecture capable of performing data sparsification at pixel level. APSEL4D has been characterized in terms of charge collection efficiency and intrinsic spatial resolution under different conditions of discriminator threshold settings using a 12GeV/c proton beam in the T9 area of the CERN PS. We observe a maximum hit efficiency of 92% and we estimate an intrinsic resolution of about 14μm. The data driven approach of the tracking detector readout chips has been successfully used to demonstrate the possibility to build a Level 1 trigger system based on associative memories. The analysis of the beam test data is critically reviewed along with the characterization of the device under test.
Barkas effect for antiproton stopping in H2 Lodi Rizzini, E; Bianconi, A; Bussa, M P ...
Physical review letters,
2002-Oct-28, 20021028, Letnik:
89, Številka:
18
Journal Article
Recenzirano
We report the stopping power of molecular hydrogen for antiprotons of kinetic energy above the maximum (approximately 100 keV) with the purpose of comparing with the proton one. Our result is ...consistent with a positive difference in antiproton-proton stopping powers above approximately 250 keV and with a maximum difference between the stopping powers of 21%+/-3% at around 600 keV.
The electromagnetic calorimeter of the HERA-B experiment Avoni, G.; Baldanza, C.; Bargiotti, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2001, Letnik:
461, Številka:
1
Journal Article
Recenzirano
The electromagnetic calorimeter of the HERA-B experiment employs the “shashlik” technology of sampled scintillator/tungsten(lead) sandwiches readout by photomultipliers. In this paper, we present a ...general overview of the system and the present results on energy and spatial resolution. The performances of the fast electron pre-trigger system are quoted as well.
A study of the angular distributions of leptons from decays of
J
/
ψ
’s produced in p-C and p-W collisions at
has been performed in the
J
/
ψ
Feynman-
x
region −0.34<
x
F
<0.14 and for
J
/
ψ
...transverse momenta up to 5.4 GeV/
c
. The data were collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The results, based on a clean selection of 2.3×10
5
J
/
ψ
’s reconstructed in both the
e
+
e
−
and
μ
+
μ
−
decay channels, indicate that
J
/
ψ
’s are produced polarized. The magnitude of the effect is maximal at low
p
T
. For
p
T
>1 GeV/
c
a significant dependence on the reference frame is found: the polar anisotropy is more pronounced in the Collins-Soper frame and almost vanishes in the helicity frame, where, instead, a significant azimuthal anisotropy arises.
We have searched for Theta+(1540) and Xi(--)(1862) pentaquark candidates in proton-induced reactions on C, Ti, and W targets at midrapidity and square root of s = 41.6 GeV. In 2 x 10(8) inelastic ...events we find no evidence for narrow (sigma approximately 5 MeV) signals in the Theta+ --> pK0(S) and Xi(--) --> Xi- pi- channels; our 95% C.L. upper limits (UL) for the inclusive production cross section times branching fraction B dsigma/dy/(y approximately 0) are (4-16) mub/N for a Theta+ mass between 1521 and 1555 MeV, and 2.5 mub/N for the Xi(--). The UL of the yield ratio of Theta+/Lambda(1520) < (3-12)% is significantly lower than model predictions. Our UL of B Xi(--)/Xi(1530)0 < 4% is at variance with the results that have provided the first evidence for the Xi(--).
In the design of the Silicon Vertex Tracker for the high luminosity SuperB collider, very challenging requirements are set by physics and background conditions on its innermost Layer0: small radius ...(about 1.5cm), resolution of 10–15μm in both coordinates, low material budget <1%X0, and the ability to withstand a background hit rate of several tens of MHz/cm2. Thanks to an intense R&D program the development of Deep NWell CMOS MAPS (with the ST Microelectronics 130nm process) has reached a good level of maturity and allowed for the first time the implementation of thin CMOS sensors with similar functionalities as in hybrid pixels, such as pixel-level sparsification and fast time stamping. Further MAPS performance improvements are currently under investigation with two different approaches: the INMAPS CMOS process, featuring a quadruple well and a high resistivity substrate, and 3D CMOS MAPS, realized with vertical integration technology. In both cases specific features of the processes chosen can improve charge collection efficiency, with respect to a standard DNW MAPS design, and allow to implement a more complex in-pixel logic in order to develop a faster readout architecture. Prototypes of MAPS matrix, suitable for application in the SuperB Layer0, have been realized with the INMAPS 180nm process and the 130nm Chartered/Tezzaron 3D process and results of their characterization will be presented in this paper.
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