This article reports the first operation of a double-sided CMOS pixelated ladder in a collider experiment, namely in the inner tracker volume of the Belle II experiment during the Phase 2 run of the ...SuperKEKB collider. Design and integration of the detector system in the experiment interaction region is first described. The two modules operated almost continuously during slightly more than four months, recording data to monitor the hit rate close to beams. Details of the off-line data analysis are provided and a method to estimate particle momentum from the 2 hits measured per crossing particle is proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
With the purpose of measuring simultaneously the proton and electron environmentusing a single sensitive device, we propose a CMOS pixel sensor featuring a 10 mm2 sensitivearea, counting capability ...up to 10 super(7)/cm super(2)/s and with a minimal error due to pileup of two closeparticle impacts on the matrix. The proposed architecture includes a 64 x 64 square pixel matrixwith 50 mu m pitch size, 64 column level 3-bit ADCs to provide an appropriate energy resolution, andan embedded digital logic that directly calculates the particle properties from the hit informationprovided by the pixels. To validate experimentally the expected performance within the year 2012, a first prototype has been designed and fabricated in a 0.35 mu m process without the integrateddigital processing part. The device simulation and design architecture are presented.
CMOS Monolithic Active Pixel Sensors (MAPS) demonstrate excellent performances in the field of charged particle tracking. A single point resolution of 1--2 mu m and a detection efficiency close to ...100% were routinely observed with various MAPS designs featuring up to 10 super(6) pixels on active areas as large as 4 cm super(2)1. Those features make MAPS an interesting technology for vertex detectors in particle and heavy ion physics. In order to adapt the sensors to the high particle fluxes expected in this application, we designed a sensor with fast column parallel readout and partially depleted active volume. The latter feature was expected to increase the tolerance of the sensors to non-ionizing radiation by one order of magnitude with respect to the standard technology. This paper discusses the novel sensor and presents the results on its radiation tolerance.
Proton imaging can be seen as a powerful technique for on-line monitoring of ion range during carbon ion therapy irradiation. The protons detection technique uses, as three-dimensional tracking ...system, a set of CMOS sensor planes. A simulation toolkit based on GEANT4 and ROOT is presented including detector response and reconstruction algorithm.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A high resolution beam telescope, based on CMOS Monolithic Active Pixels Sensors (MAPS), is being developed under the EUDET collaboration, a coordinated detector R&D program for a future ...international linear collider. A very good spatial resolution < 5 mum, a fast readout time of 100 mus for the whole array (136 times 576 pixels) and a high granularity can be obtained with this technology. A recent fast MAPS chip, designed in AMS CMOS 0.35 mum Opto process with 14 mum epitaxial layer and called MIMOSA22, was submitted to foundry. MIMOSA22 has an active area of 26.5 mm 2 with a pixel pitch of 18.4 mum arranged in an array of 576 rows by 136 columns where 8 columns have analog test outputs and 128 have their outputs connected to offset compensated discriminator stages. The pixel array is divided in seventeen blocks of pixels, with different amplification gain, diode size, pixel architecture and is addressed row-wise through a serially programmable (JTAG) sequencer. Discriminators have a common adjustable threshold with internal DAC. MIMOSA22 is the last chip (IDC-Intermediate Digital Chip), before the final sensor of the EUDET-JRA1 beam telescope, which will be installed on the 6 GeV electron beam line at DESY. In this paper, laboratory test results on analog and digital parts are presented. Test beam results, obtained with a 120 GeV pion beam at CERN, are also presented. In the last part of the paper, results on irradiated chips are given.
Simulation of the Belle II silicon vertex detector Kaleta, M.; Adamczyk, K.; Aggarwal, L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2022, Volume:
1032
Journal Article
Peer reviewed
Belle II is the next generation B Factory experiment operating at the SuperKEKB accelerator complex at KEK in Tsukuba, Japan. It is expected to collect 50 ab−1 of data, with a target instantaneous ...luminosity of 6.5 × 1035 cm−2s−1, which is about 30 times larger than its predecessor, Belle. In view of the ever increasing Belle II data sample, accurate simulation of the detector is growing in importance. This poses a challenging task of compromising between the realistic modeling of the response of individual detector components and reasonable performance in terms of CPU time of the simulation. In this paper we describe the simulation of the silicon vertex detector, its performance against collision data and optimization.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The silicon vertex detector of the Belle II experiment Gabrielli, A.; Adamczyk, K.; Aihara, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2024, Volume:
1064
Journal Article
Peer reviewed
The silicon vertex detector (SVD) is a four-layer double-sided strip detector installed at the heart of the Belle II experiment, taking data at the high-luminosity B-Factory SuperKEKB since 2019. SVD ...has been operating smoothly and reliably, showing a stable and above-99% hit efficiency, and a large signal-to-noise ratio in all sensors. In June 2022 the data-taking of the Belle II experiment was stopped for the Long Shutdown 1, primarily required to complete the vertex detector (VXD) with the inner two-layer DEPFET detector and to upgrade several components of the accelerator. This article reports on the excellent performance of SVD in terms of the signal-to-noise ratio, the hit position resolution, as well as the hit-time resolution. We briefly describe the challenges and delicate phases of the VXD re-installation and the SVD status for operation starting in early 2024. In SVD layer 3, which is closest to the interaction point, the average occupancy has been less 0.5%, well below the estimated limit for acceptable tracking performance. However, higher machine backgrounds are expected at increased luminosity, and so also increased hit occupancy. To enhance the robustness of offline software in a high-background environment, new algorithms of background suppression using the excellent SVD hit-time information have been developed, which allows a significant reduction of the fake rate, while preserving the tracking efficiency.
With the increasing luminosity also the radiation levels are expected to increase, with possible deterioration of the sensor performance. The SVD integrated dose is estimated by the correlation of the SVD occupancy with the dose rate measured by the diamonds of the radiation monitor and beam-abort system.
The effects of radiation damage are starting and in good agreement with our expectations. So far, no harmful impact due to the radiation damage on the detector performance has been observed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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