The development of micro-scale mechanical systems has been moving rapidly, allowing an opportunity to the semiconductor detectors to have ever more power located on the active region. Miniaturization ...associated with micro-channel technologies allows the design of micro-system structures that are able to cool silicon pixel detectors with power of the order of some W/cm
2 with thickness less than 0.3% of radiation length. We present the design and thermo-hydraulic test results for low material budget support and cooling obtained through
forced liquid convection in micro-channels, developed for the innermost layer (Layer 0) of SuperB silicon vertex tracker.
Pixel detectors at future colliders will need to match very stringent requirement on position resolution. To ensure the needed mechanical stability and the removal of the power dissipated by the ...read-out electronic, the support structure and cooling add an important contribution to the total material in the active area, in terms of radiation length. We present the development, the construction and the mechanical–thermal characterization of prototypes of light material support for pixel detectors with microchannel for heat evacuation through forced convection of liquid coolant.
The solution we choose shows several advantages: heat exchange is taking place efficiently due to the high ratio surface/volume and so high thermal conductivities can be obtained, minimally affecting the stiffness of the structure; the thermal resistances are reduced because of the contiguity between the fluid and the circuit dissipating power; the uniformity of temperature on the surface covered by of the sensors is also kept under control. Several prototypes implementing different geometries of micro-machined channels have been realized in composites materials (CFRP). FEA studies have been performed to validated the experimental test conducted in the thermo-fluid dynamic test bench we recently assembled in the INFN Pisa laboratory.
Abstract
The Silicon Vertex Detector of Belle II is a
state-of-the-art tracking and vertexing system based on double-sided
silicon strip sensors, designed and fabricated by a large
international ...collaboration in the period 2012–2018. Since 2019 it
has been in operation providing high quality data with a small
number of defective channels (<1%), a large hit-finding
efficiency (>99%), a good signal-to-noise ratio (well in excess
of 10 for all sensor configurations and tracks). Together with the
good control over the alignment, these are all essential factors to
achieve good tracking reconstruction and physics performance. In
this extended paper we try to document all the aspects of the SVD
challenges and achievements, in the spirit of providing information
to the broader community and help the development of high quality
detector systems, which are essential tools to carry out physics
research.
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.
This paper shows the hardware and the procedure utilized to test all components of the readout system (cables, FADC boards, junction boards) of the Belle II Silicon Vertex Detector after the series ...production. For the FADC board special testing hardware and firmware were designed and created to check all digital and analog inputs and outputs as well as all data interconnections on the board. The main FPGA on the FADC board generates digital signals which are converted to periodic analog differential alternating voltages up to 40 MHz on the FADC board tester, which then are fed into the analog inputs of the FADC board. Histograms and scans of the samples are recorded by using random equivalent-time sampling or sequential equivalent-time sampling, allowing to characterize the behavior of the system with a much higher bandwidth than the ADCs could do with conventional measurements. Small changes of parameters of the assembly (like using a cable of different length) lead to significant changes of the measured values, creating a sensitive testing instrument. The shapes of the distributions are analyzed and compared to references by software which then decides if a test is passed or not.
The commissioning setup of the whole readout chain, with all the final components including the final detector, has been tested in three phases. The respective graphs of the signal-to-noise ratios of the strips of a detector module and histograms of the noise development of the whole detector show very high consistency of the SVD readout system.
Commissioning of the Belle II Silicon Vertex Detector Casarosa, G.; 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 experiment at the SuperKEKB collider of KEK (Japan) will accumulate 50 ab−1 of e+e- collision data at an unprecedented instantaneous luminosity of 8⋅ 1035 cm−2s−1, about 40 times larger ...than its predecessor. The Belle II vertex detector plays a crucial role in the rich Belle II physics program, especially for time-dependent measurements. It consists of two layers of DEPFET-based pixels and four layers of double sided silicon strip sensors (SVD detector). We report here results of the standalone commissioning of the SVD and highlights from the first cosmic runs acquired in Belle II. We also report on reconstruction performances of a reduced-scale version of the SVD operated during the accelerator commissioning in 2018.
The Belle II silicon vertex detector: Assembly and initial results Thalmeier, R.; Casarosa, G.; Schwanda, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
Odprti dostop
The “chip-on-sensor” concept of this detector minimizes the distance of the signal propagation from the double-sided silicon detector strips to the readout chips and thus reduces noise from strip ...capacitance. One half of the detector is built, the second half is being assembled at the time of writing. Prototypes have been tested in several test beams as well as in the so-called Phase 2 setup inside the detector structure. First results from a commissioning run of the Belle-II prototype SVD detector are presented. The measured signal-to-noise and timing performance are found to be according to design specifications.
•The Belle-II Silicon Vertex Detector is based on a “chip-on-sensor” concept.•One half of the detector is built, the second half is being assembled.•Prototypes have been tested in a commissioning run inside the detector structure.•The measured SNR and hit time are found to be according to design specifications.
The Belle II SVD data readout system Thalmeier, R.; Adamczyk, K.; Aihara, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2017, Letnik:
845
Journal Article
Recenzirano
Odprti dostop
The Belle II Experiment at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, will explore the asymmetry between matter and antimatter and search for new physics beyond the ...standard model.
172 double-sided silicon strip detectors are arranged cylindrically in four layers around the collision point to be part of a system which measures the tracks of the collision products of electrons and positrons. A total of 1748 radiation-hard APV25 chips read out 128 silicon strips each and send the analog signals by time-division multiplexing out of the radiation zone to 48 Flash Analog Digital Converter Modules (FADC).
Each of them applies processing to the data; for example, it uses a digital finite impulse response filter to compensate line signal distortions, and it extracts the peak timing and amplitude from a set of several data points for each hit, using a neural network.
We present an overview of the SVD data readout system, along with front-end electronics, cabling, power supplies and data processing.
The silicon vertex detector of the Belle II experiment Adamczyk, K.; Aihara, H.; Angelini, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
Odprti dostop
The silicon vertex detector of the Belle II experiment, structured in a lantern shape, consists of four layers of ladders, fabricated from two to five silicon sensors. The APV25 readout ASIC chips ...are mounted on one side of the ladder to minimize the signal path for reducing the capacitive noise; signals from the sensor backside are transmitted to the chip by bent flexible fan-out circuits. The ladder is assembled using several dedicated jigs. Sensor motion on the jig is minimized by vacuum chucking. The gluing procedure provides such a rigid foundation that later leads to the desired wire bonding performance. The full ladder with electrically functional sensors is consistently completed with a fully developed assembly procedure, and its sensor offsets from the design values are found to be less than 200μm. The potential functionality of the ladder is also demonstrated by the radioactive source test.
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