We report on further developments of our proposed design approach for a full in-pixel signal processing chain of deep N-well monolithic active pixel sensor, by exploiting the triple well option of a ...CMOS 130
nm process. Two different geometries of the collecting electrode (namely “Apsel 3
T
1
M
1” and “Apsel 3
T
1
M
2”) was implemented to compare their charge collection efficiency. The results of the characterization of the various versions of pixel matrices with a pion beam of 120
GeV/
c at the SPS H6 CERN facility will be presented. The performances of an “Apsel 3
T
1” chip irradiated with a dose up to 10
Mrad (Co
60) was also measured. Comparison will be presented among the irradiated and the new chip showing the impact of radiation damages on tracking efficiencies.
The high rate data acquisition system for the SLIM5 beam test Fabbri, L.; Bruschi, M.; Di Sipio, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Letnik:
617, Številka:
1
Journal Article
Recenzirano
In September 2008 the Slim5 collaboration submitted a low material budget silicon demonstrator to test with protons at the PS beam at CERN. The beam test setup was composed of a four double sided ...microstrip reference telescope and different detectors (DUTs) placed inside: a 4k-Pixel Matrix of Deep N Well MAPS, developed in a 130
nm CMOS Technology and a high resistivity double sided silicon detector, with short strips at
45
∘
angle to the detectors edge, read out by the FSSR2 chip. All the systems were self-triggered and read out by a fast DAQ system. In the poster the beam test setup as the data acquisition and the trigger system are explained and the data acquisition performances are shown.
The Belle II experiment at the SuperKEKB electron–positron collider aims to collect an unprecedented data set of 50ab−1 to study CP-violation in the B-meson system and to search for Physics beyond ...the Standard Model. SuperKEKB is already the world’s highest-luminosity collider. In order to collect the planned data set within approximately one decade, the target is to reach a peak luminosity of 6 × 1035cm−2s−1 by further increasing the beam currents and reducing the beam size at the interaction point by squeezing the betatron function down to βy∗=0.3mm. To ensure detector longevity and maintain good reconstruction performance, beam backgrounds must remain well controlled. We report on current background rates in Belle II and compare these against simulation. We find that a number of recent refinements have significantly improved the background simulation accuracy. Finally, we estimate the safety margins going forward. We predict that backgrounds should remain high but acceptable until a luminosity of at least 2.8 × 1035cm−2s−1 is reached for βy∗=0.6mm. At this point, the most vulnerable Belle II detectors, the Time-of-Propagation (TOP) particle identification system and the Central Drift Chamber (CDC), have predicted background hit rates from single-beam and luminosity backgrounds that add up to approximately half of the maximum acceptable rates.
Abstract We present a measurement of the Cabibbo-Kobayashi-Maskawa unitarity triangle angle ϕ 3 (also known as γ) using a model-independent Dalitz plot analysis of B + → D ( K S 0 $$ {K}_S^0 $$ h + h ...− )h +, where D is either a D 0 or D ¯ $$ \overline{D} $$ 0 meson and h is either a π or K. This is the first measurement that simultaneously uses Belle and Belle II data, combining samples corresponding to integrated luminosities of 711 fb −1 and 128 fb −1, respectively. All data were accumulated from energy-asymmetric e + e − collisions at a centre-of-mass energy corresponding to the mass of the Υ(4S) resonance. We measure ϕ 3 = (78.4 ± 11.4 ± 0.5 ± 1.0)°, where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is from the uncertainties on external measurements of the D-decay strong-phase parameters.
The paper describes a mixed-mode ASIC composed of a fast readout architecture that interfaces with a matrix of 4096 Monolithic Active Pixel Sensors (MAPS). The matrix has 128 columns and 32 rows of ...pixels and is divided into 256 regions of 4 times 4 pixels, named macro-pixels (MPs). The chip is an upgrade of a smaller version having 256 pixels that was designed and tested. The two chips were designed via STM 130 nm CMOS technology. The pixel dimension is 50 by 50 mum 2 . The work is aimed at improving the design of MAPS detectors with an on-chip fast sparsification system, for particle tracking, to match the requirements of future high-energy physics experiments. The readout architecture implemented is data driven to extend the flexibility of the system, to be also used in first level triggers on tracks in vertex detectors. Simulations indicate that the readout system can cope with an average hit rate up to 100 MHz/cm 2 if a master clock of 80 MHz is used, while maintaining an overall efficiency over 99%.
The Silicon Vertex Tracker for the SuperB detector is designed as an evolution of the BaBar SVT, based on double-sided strip detectors. The wider acceptance in polar angle (down to 300 milliradians) ...will imply larger incidence angles (up to 73°) on the sensors. On the z-side (reading out the z coordinate, along the beam direction) this results in large clusters with small signal values on individual channels. For optimum performance it would be desirable to continuously vary the sensor pitch on z-side versus position. An easy and convenient way to approximate this configuration is to bond two or three adjacent strips to a single trace of the fanout circuit that connects the strips to the front-end electronics (the so-called ‘pairing’ option). In order to accurately measure the total capacitance of strips in various pairing configurations (×2,×3,×4) two test detectors have been assembled on PCBs, and various strip connection schemes have been implemented by wire bonding, on p and on n-side, respectively. Capacitance and dissipation factor have been measured versus bias voltage and frequency. These data are being used to estimate the noise contribution of the detector and to choose the best z-side connection scheme in the SVT.
Beam background study for the Belle II Silicon Vertex Detector Tanigawa, H.; Adamczyk, K.; Aihara, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2020, Letnik:
982
Journal Article
Recenzirano
The Belle II experiment aims to accumulate 50ab−1 of e+e− collision data at the SuperKEKB asymmetric energy collider (Tsukuba, Japan). The first physics data using all Belle II detectors were taken ...in spring 2019.
In the vast physics program of the Belle II experiment, the vertex detector plays a crucial role for the determination of the B-meson decay vertices. It consists of two inner layers of pixelated silicon detectors and four outer layers of double-sided silicon strip detectors (SVD).
To achieve a design luminosity of 8×1035cm−2s−1, 40 times higher than the recorded luminosity of its predecessor, the SuperKEKB collider squeezes the beams to a vertical size of 50 nm (“nano-beam scheme”) and doubles the beam currents.
Therefore, the detectors are required to tolerate intense beam induced background due to the very high luminosity. During the 2019 spring run we measured the occupancy rate in the SVD to estimate the level of the beam induced background. With the low initial luminosity, the observed beam induced background mostly originated from Touschek processes and beam-gas scattering within individual beams. Since these different background contributions depend differently on accelerator conditions, such as the beam current, beam size and pressure, they can be disentangled. We estimate the background rate of each contribution and compare them with simulated ones. The results enable us to predict the background levels at increased beam currents and luminosity in the coming years. They also hint at background mitigation measures for running at higher luminosity. In this proceeding we present the results of our study of the beam induced background in the SVD and the prospects for future operation.
The Belle-II VerteX Detector (VXD) is a 6 layers silicon tracker device that will cope with an unprecedented luminosity of 8 × 10 35 cm -2 s -1 achievable by the new SuperKEKB e + e - collider, now ...under commissioning at the KEK laboratory (Tsukuba, Japan). A radiation monitoring and beam abort system has been developed based on single-crystal s-CVD diamond sensors. The sensors will be placed in 20 key positions in the vicinity of the interaction region. The severe space limitations require a remote readout of the sensors. In this contribution we present the system design, along with the sensor characterisation procedure. We present also the preliminary results with the prototype system during the first SuperKEKB commissioning phase in February-June 2016.
Run and slow control system of the Belle II silicon vertex detector Irmler, C.; Aihara, H.; Aziz, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
Odprti dostop
The Belle II Silicon Vertex Detector (SVD) was installed recently and has been prepared for physics run at SuperKEKB factory, Tsukuba, Japan. For a reliable operation and data taking of the SVD, a ...sophisticated and robust run and slow control system has been implemented, which utilizes the Experimental Physics and Industrial Control System (EPICS) framework. EPICS uses client/server and publish/subscribe techniques to communicate between the various sub-systems and computers. The information exchange between the different pieces of software and computers is done by process variables (PVs). These PVs are provided by input/output controllers (IOCs), which communicate and interface with the hardware components. The Belle II SVD slow and run control comprises five groups of subsystems, which are SVD DAQ controller, Flash ADC controller, environmental monitors and interlocks, power supplies and EPICS infrastructure services. In this paper we describe the tasks and the implementation of the individual sub-systems, the interaction between them and the global Belle II run and slow control as well as the first experience from commissioning and initial operation of the SuperKEKB accelerator.
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