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Ivan Perić

Publications and source records attributed to Ivan Perić.

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HitPix3 -- a new HV-CMOS active pixel sensor for ion beam therapy

Particle therapy is a well-established clinical treatment of tumors and so far, more than one hundred centers are in operation around the world. High accuracy on position and dose rate in beam monitoring are major cornerstones of clinical success in particle therapy. A high voltage CMOS (HV-CMOS) monolithic active pixel sensor was developed for this beam monitoring system. The HV-CMOS technology has demonstrated many advantages over other technologies in dealing with radiation tolerance. This HV-CMOS sensor was produced with a 180 nm commercial technology on high-resistivity substrate. The HitPix sensor features several specific design details for operation in a high-intensity ion beam environment: hit-counting pixels, on-sensor projection calculation, radiation tolerant design and frame-based readout. It has a 9775 $μ$m $\times$ 10110 $μ$m sensor area with 200 $μ$m $\times$ 200 $μ$m pixel size. The new HitPix3 has a number of improvements, including a modified in-pixel amplifier, on-sensor calculation of beam profile projection in two dimensions, and in-pixel threshold tuning capacity. The functionality of these features was confirmed in laboratory tests of unirradiated HitPix3 sensors, making the HitPix3 an important step in developing a sensor for use in ion beam monitoring.

physics.ins-det

Evaluation of gamma-ray response of the AstroPix4 HV-CMOS active pixel sensor

AstroPix is a novel high-voltage CMOS active pixel sensor being developed for a next generation gamma-ray space telescope, AMEGO-X. To meet AMEGO-X instrument requirements, AstroPix must achieve full depletion of its $500~\rm{μm}$ thick, $500~\rm{μm}$-pitch pixels. It must be sensitive to gamma rays in the range of $25-700$ keV, with the energy resolution at 122 keV of $<10$%. Furthermore, given the space-based nature of AMEGO-X, the power consumption of AstroPix needs to be lower than $1.5~\rm{mW/{cm}^2}$. We report the gamma-ray response of the latest version of AstroPix, AstroPix4. The chip contains $16\times 13$ array of $500~\rm{μm}$-pitch pixels. The power consumption is estimated to be about $2~\rm{mW/{cm}^2}$, which is approximately half the power of the previous AstroPix version. The input capacitance is reduced, allowing for the detection of the 14 keV photopeak from $\rm{^{57}Co}$ and a moderate energy resolution of 14% at 122 keV. The dynamic range is estimated to be in the range from 14 keV to $\sim250$ keV. We found that the sensor depletion layer expands as expected and the measured depletion depth is approximately $90~\rm{μm}$ when biased at $-240$ V.

astro-ph.IM

TelePix2: Full scale fast region of interest trigger and timing for the EUDET-style telescopes at the DESY II Test Beam Facility

With increasing demands by future and current upgrades of particle physics experiments on rate capabilities and time resolution, the requirements on test beams are also increasing. The current infrastructure at the DESY II test beam facility includes particle tracking telescopes with long integration times, no additional timing but excellent spatial resolution. This results in readouts with multiple particles per trigger, causing ambiguities in tracking and assigning particles to triggers. Also, it is likely not to trigger on particles that pass through a small device under test, leading to inefficient data taking. These issues can be solved by adding TelePix2 as a timing and flexible region of interest trigger layer. TelePix2 is a full scale HV-CMOS chip based on the successful small scale prototype TelePix. The DAQ system and the sensors performance featuring efficiencies above 99 % and a time resolution of 3.844(2) ns are presented. The integration into EUDAQ2 and the AIDA-TLU to seamlessly work in the test beam environment as well as into the analysis chain is described. First successful use cases are highlighted to conclude that TelePix2 is a well-suited timing and trigger layer for test beams

hep-ex

Performance evaluation of the high-voltage CMOS active pixel sensor AstroPix for gamma-ray space telescopes

AstroPix is a novel monolithic high-voltage CMOS active pixel sensor proposed for next generation medium-energy gamma-ray observatories like the All-sky Medium Energy Gamma-ray Observatory eXplorer (AMEGO-X). For AMEGO-X AstroPix must maintain a power consumption of less than $1.5~\rm{mW/{cm}^2}$ while having a pixel pitch of up to $500~\rm{μm}$. We developed the second and third versions of AstroPix, namely AstroPix2 and AstroPix3. AstroPix2 and AstroPix3 exhibit power consumptions of $3.4~\rm{mW/{cm}^2}$ and $4.1~\rm{mW/{cm}^2}$, respectively. While AstroPix2 has a pixel pitch of $250~\rm{μm}$, AstroPix3 achieves the desired size for AMEGO-X with a pixel pitch of $500~\rm{μm}$. Performance evaluation of a single pixel in an AstroPix2 chip revealed a dynamic range from 13.9 keV to 59.5 keV, with the energy resolution meeting the AMEGO-X target value ($<10\%$ (FWHM) at 60 keV). We performed energy calibration on most of the pixels in an AstroPix3 chip, yielding a mean energy resolution of 6.2 keV (FWHM) at 59.5 keV, with 44.4% of the pixels satisfying the target value. The dynamic range of AstroPix3 was assessed to span from 22.2 keV to 122.1 keV. The expansion of the depletion layer aligns with expectations in both AstroPix2 and AstroPix3. Furthermore, radiation tolerance testing was conducted on AstroPix. An AstroPix2 chip was subjected to an equivalent exposure of approximately 10 Gy from a high-intensity $\rm{^{60}Co}$ source. The chip was fully operational after irradiation although a decrease in gain by approximately 4% was observed.

astro-ph.IM

TelePix -- A fast region of interest trigger and timing layer for the EUDET Telescopes

Test beam facilities are essential to study the response of novel detectors to particles. At the DESY II Test Beam facility, users can test their detectors with an electron beam with a momentum from 1-6 GeV. To track the beam particles, EUDET-style telescopes are provided in each beam area. They provide excellent spatial resolution, but the time resolution is limited by the rolling shutter architecture to a precision of approximately 230 $μ$s. Since the demand on particle rates -- and hence track multiplicities -- is increasing timing is becoming more relevant. DESY foresees several upgrades of the telescopes. TelePix is an upgrade project to provide track timestamping with a precision of better than 5 ns and a configurable region of interest to trigger the telescope readout. Small scale prototypes have been characterised in laboratory and test beam measurements. Laboratory tests with an injection corresponding to 2300 electrons show a S/N of above 20. Test beam characterization shows efficiencies of above 99% over a threshold range of more than 100 mV and time resolutions of 2.4 ns at low noise rates.

physics.ins-det

A Beam Monitor for Ion Beam Therapy based on HV-CMOS Pixel Detectors

Particle therapy is a well established clinical treatment of tumors. More than one hundred particle therapy centers are in operation world wide. The advantage of using hadrons like protons or carbon ions as particles for tumor irradiation is the distinct peak in the depth dependent energy deposition, which can be exploited to accurately deposit dose in the tumor cells. To guarantee this, high accuracy of monitoring and control of the particle beam is of utmost importance. Before the particle beam enters the patient, it traverses a monitoring system which has to give fast feedback to the beam control system on position and dose rate of the beam while minimally interacting with the beam. The multi-wire chambers mostly used as beam position monitor have their limitations when fast response time is required (drift time). Future developments like MRI-guided ion beam therapy pose additional challenges for the beam monitoring system like tolerance of magnetic fields and acoustic noise (vibrations). Solid-state detectors promise to overcome these limitations and the higher resolution they offer can create additional benefits. This article presents the evaluation of an HV-CMOS detector for beam monitoring, provides results from feasibility studies in a therapeutic beam and summarizes the concepts towards the final large-scale assembly and readout system.

physics.med-ph

X-ray characterization of BUSARD chip: A HV-SOI monolithic particle detector with pixel sensors under the buried oxide

This work presents the design of BUSARD, an application specific integrated circuit (ASIC) for the detection of ionizing particles. The ASIC is a monolithic active pixel sensor which has been fabricated in a High-Voltage Silicon-On-Insulator (HV-SOI) process that allows the fabrication of a buried N+ diffusion below the Buried OXide (BOX) as a standard processing step. The first version of the chip, BUSARD-A, takes advantage of this buried diffusion as an ionizing particle sensor. It includes a small array of 13$\times$13 pixels, with a pitch of $80\,μ$m, and each pixel has one buried diffusion with a charge amplifier, discriminator with offset tuning and digital processing. The detector has several operation modes including particle counting and Time-over-Threshold (ToT). An initial X-ray characterization of the detector was carried out, obtaining several pulse height and ToT spectra, which then were used to perform the energy calibration of the device. The Molybdenum $\mathbf{K_α}$ emission was measured with a standard deviation of $127\,e^{-}$ of ENC by using the analog pulse output, and with $276\,e^{-}$ of ENC by using the ToT digital output. The resolution in ToT mode is dominated by the pixel-to-pixel variation.

physics.ins-det

The Mu3e experiment: Toward the construction of an HV-MAPS vertex detector

The Mu3e experiment searches for the lepton flavor violating decay $μ^+~\rightarrow~e^+~e^+~e^-$ with an ultimate aimed sensitivity of 1 event in $10^{16}$ decays. This goal can only be achieved by reducing the material budget per tracking layer to $X/X_0 \approx 0.1 \%$. High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) which are thinned to $50\ μm$ serve as sensors. Gaseous helium is chosen as coolant. Results of recent studies related to the sensor prototypes, the helium cooling, and module prototyping are presented. The recent chip submission MuPix10 has proven its functionality regarding efficiency and time resolution. The helium cooling system for the inner tracker could be verified using a full-scale prototype. A complete prototype equipped with MuPix10 chips will be tested inside the Mu3e magnet in summer 2021.

physics.ins-det

MuPix10: First Results from the Final Design

Many years of research and development of High Voltage Monolithic Active Pixel Sensors (HVMAPS) have culminated in the final design for the Mu3e pixel sensor. MuPix10 is a fully monolithic sensor with an active pixel matrix size of $20\times20\,\mathrm{mm}^2$ produced in the $180\,\mathrm{nm}$ HV-CMOS process at TSI Semiconductors. The pixel size is $80\times80\,\mathrm{μm}^2$. Hits are read out using a column-drain architecture and sent over up to four serial links with up to $1.6\,\left.\mathrm{Gbit}\middle/\mathrm{s}\right.$ each. By means of DC/DC converters and exclusive usage of on-chip biasing, MuPix10 is fully operable with a minimal set of electrical connections. This is an integral requirement by the Mu3e experiment since it enables the construction of ultra-thin pixel modules with $0.1\,$% of a radiation length per layer. First results from lab characterisation and testbeam campaigns are presented.

physics.ins-det

Charge collection characterisation with the Transient Current Technique of the ams H35DEMO CMOS detector after proton irradiation

This paper reports on the characterisation with Transient Current Technique measurements of the charge collection and depletion depth of a radiation-hard high-voltage CMOS pixel sensor produced at ams AG. Several substrate resistivities were tested before and after proton irradiation with two different sources: the 24 GeV Proton Synchrotron at CERN and the 16.7 MeV Cyclotron at Bern Inselspital.

physics.ins-det

Efficiency and timing performance of the MuPix7 high-voltage monolithic active pixel sensor

The MuPix7 is a prototype high voltage monolithic active pixel sensor with 103 times 80 um2 pixels thinned to 64 um and incorporating the complete read-out circuitry including a 1.25 Gbit/s differential data link. Using data taken at the DESY electron test beam, we demonstrate an efficiency of 99.3% and a time resolution of 14 ns. The efficiency and time resolution are studied with sub-pixel resolution and reproduced in simulations.

physics.ins-det

The P2 Experiment - A future high-precision measurement of the electroweak mixing angle at low momentum transfer

This article describes the future P2 parity-violating electron scattering facility at the upcoming MESA accelerator in Mainz. The physics program of the facility comprises indirect, high precision search for physics beyond the Standard Model, measurement of the neutron distribution in nuclear physics, single-spin asymmetries stemming from two-photon exchange and a possible future extension to the measurement of hadronic parity violation. The first measurement of the P2 experiment aims for a high precision determination of the weak mixing angle to a precision of 0.14% at a four-momentum transfer of Q^2 = 4.5 10^{-3} GeV^2. The accuracy is comparable to existing measurements at the Z pole. It comprises a sensitive test of the standard model up to a mass scale of 50 TeV, extendable to 70 TeV. This requires a measurement of the parity violating cross section asymmetry -39.94 10^{-9} in the elastic electron-proton scattering with a total accuracy of 0.56 10^-9 (1.4 %) in 10,000 h of 150 \micro A polarized electron beam impinging on a 60 cm liquid H_2 target allowing for an extraction of the weak charge of the proton which is directly connected to the weak mixing angle. Contributions from gamma Z-box graphs become small at the small beam energy of 155 MeV. The size of the asymmetry is the smallest asymmetry ever measured in electron scattering with an unprecedented goal for the accuracy. We report here on the conceptual design of the P2 spectrometer, its Cherenkov detectors, the integrating read-out electronics as well as the ultra-thin, fast tracking detectors. There has been substantial theory work done in preparation of the determination of the weak mixing angle. The further physics program in particle and nuclear physics is described as well.

nucl-ex

Characterization of Fully Depleted CMOS Active Pixel Sensors on High Resistivity Substrates for Use in a High Radiation Environment

Depleted CMOS active sensors (DMAPS) are being developed for high-energy particle physics experiments in high radiation environments, such as in the ATLAS High Luminosity Large Hadron Collider (HL-LHC). Since charge collection by drift is mandatory for harsh radiation environment, the application of high bias voltage to high resistive sensor material is needed. In this work, a prototype of a DMAPS was fabricated in a 150nm CMOS process on a substrate with a resistivity of >2 kΩcm that was thinned to 100 μm. Full depletion occurs around 20V, which is far below the breakdown voltage of 110 V. A readout chip has been attached for fast triggered readout. Presented prototype also uses a concept of sub-pixel en/decoding three pixels of the prototype chip are readout by one pixel of the readout chip. Since radiation tolerance is one of the largest concerns in DMAPS, the CCPD_LF chip has been irradiated with X-rays and neutrons up to a total ionization dose of 50 Mrad and a fluence of 10E15neq/cm2, respectively.

physics.ins-det

The MuPix System-on-Chip for the Mu3e Experiment

Mu3e is a novel experiment searching for charged lepton flavor violation in the rare decay $μ^+ \rightarrow e^+e^-e^+$. Decay vertex position, decay time and particle momenta have to be precisely measured in order to reject both accidental and physics background. A silicon pixel tracker based on $50\,μ$m thin high voltage monolithic active pixel sensors (HV-MAPS) in a 1 T solenoidal magnetic field provides precise vertex and momentum information. The MuPix chip combines pixel sensor cells with integrated analog electronics and a periphery with a complete digital readout. The MuPix7 is the first HV-MAPS prototype implementing all functionalities of the final sensor including a readout state machine and high speed serialization with 1.25 Gbit/s data output, allowing for a streaming readout in parallel to the data taking. The observed efficiency of the MuPix7 chip including the full readout system is $\geq99\%$ in a high rate test beam.

physics.ins-det

A Tracker for the Mu3e Experiment based on High-Voltage Monolithic Active Pixel Sensors

The Mu3e experiment searches for the lepton flavour violating decay mu+ -> e+e-e+, aiming for a branching fraction sensitivity of 10^-16. This requires an excellent momentum resolution for low energy electrons, high rate capability and a large acceptance. In order to minimize multiple scattering, the amount of material has to be as small as possible. These challenges can be met with a tracker built from high-voltage monolithic active pixel sensors (HV-MAPS), which can be thinned to 50 um and which incorporate the complete read-out electronics on the sensor chip. To further minimise material, the sensors are supported by a mechanical structure built from 25 um thick Kapton foil and cooled with gaseous helium.

physics.ins-det