Design and operation of a fast high-granularity silicon detector system in a high-radiation environment

Abstract We have designed, realized and operated a fast silicon detector system (50 MHz sampling frequency) to measure the angular distribution and the multiplicity of charged secondaries produced in high-energy Pb–Pb interactions, within the NA50 experiment. We present here the detector design, discuss some of the problems faced during the commissioning and report on the first results on the operation of the full system. In particular, the questions related to the operation of an integrated high-speed binary readout in a high-radiation environment (1014 particles/cm2 and about 10 Mrads) and to the radiation effects on the system during the run will be addressed

Dosimetry of microbeam radiotherapy by flexible hydrogenated amorphous silicon detectors

Objective. Detectors that can provide accurate dosimetry for microbeam radiation therapy (MRT) must possess intrinsic radiation hardness, a high dynamic range, and a micron-scale spatial resolution. In this work we characterize hydrogenated amorphous silicon detectors for MRT dosimetry, presenting a novel combination of flexible, ultra-thin and radiation-hard features. Approach. Two detectors are explored: an n-type/intrinsic/p-type planar diode (NIP) and an NIP with an additional charge selective layer (NIP + CSC). Results. The sensitivity of the NIP + CSC detector was greater than the NIP detector for all measurement conditions. At 1 V and 0 kGy under the 3T Cu-Cu synchrotron broadbeam, the NIP + CSC detector sensitivity of (7.76 +/- 0.01) pC cGy-1 outperformed the NIP detector sensitivity of (3.55 +/- 0.23) pC cGy-1 by 219%. The energy dependence of both detectors matches closely to the attenuation coefficient ratio of silicon against water. Radiation damage measurements of both detectors out to 40 kGy revealed a higher radiation tolerance in the NIP detector compared to the NIP + CSC (17.2% and 33.5% degradations, respectively). Percentage depth dose profiles matched the PTW microDiamond detector's performance to within +/- 6% for all beam filtrations except in 3T Al-Al due to energy dependence. The 3T Cu-Cu microbeam field profile was reconstructed and returned microbeam width and peak-to-peak values of (51 +/- 1) mu m and (405 +/- 5) mu m, respectively. The peak-to-valley dose ratio was measured as a function of depth and agrees within error to the values obtained with the PTW microDiamond. X-ray beam induced charge mapping of the detector revealed minimal dose perturbations from extra-cameral materials. Significance. The detectors are comparable to commercially available dosimeters for quality assurance in MRT. With added benefits of being micron-sized and possessing a flexible water-equivalent substrate, these detectors are attractive candidates for quality assurance, in-vivo dosimetry and in-line beam monitoring for MRT and FLASH therapy

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Performance of the CMS muon trigger system in proton-proton collisions at √s = 13 TeV

The muon trigger system of the CMS experiment uses a combination of hardware and software to identify events containing a muon. During Run 2 (covering 2015-2018) the LHC achieved instantaneous luminosities as high as 2 × 10 cm s while delivering proton-proton collisions at √s = 13 TeV. The challenge for the trigger system of the CMS experiment is to reduce the registered event rate from about 40 MHz to about 1 kHz. Significant improvements important for the success of the CMS physics program have been made to the muon trigger system via improved muon reconstruction and identification algorithms since the end of Run 1 and throughout the Run 2 data-taking period. The new algorithms maintain the acceptance of the muon triggers at the same or even lower rate throughout the data-taking period despite the increasing number of additional proton-proton interactions in each LHC bunch crossing. In this paper, the algorithms used in 2015 and 2016 and their improvements throughout 2017 and 2018 are described. Measurements of the CMS muon trigger performance for this data-taking period are presented, including efficiencies, transverse momentum resolution, trigger rates, and the purity of the selected muon sample. This paper focuses on the single- and double-muon triggers with the lowest sustainable transverse momentum thresholds used by CMS. The efficiency is measured in a transverse momentum range from 8 to several hundred GeV

The optical links for the trigger upgrade of the Drift Tube in CMS

The first phase of the upgrade of the electronics of Drift Tubes (DT)in the CMS experiment is reported. It consists of the translation of the readoutand trigger data from electrical into optical and their transmission from the CMSexperimental cavern to the counting room. Collecting the full information of theDT chambers in the counting room allows the development of new trigger hardwareand algorithms

Study of SEU effects in circuits developed in 110 nm CMOS technology

Channel configuration registers of a full size prototype for the custom readout circuit of silicon double-sided microstrips of PANDA Micro Vertex Detector were tested for upset effects. The ASIC is developed in a commercial 110 nm CMOS technology and implements both Triple Modular Redundancy and Hamming Encoding techniques. Results from tests with ion and proton beams show the robustness level of these two techniques against the upset effects and allow the evaluation of that commercial 110 nm technology in the PANDA experiment

High-Speed, Radiation-Tolerant Laser Drivers in 0.13 μ\mum CMOS Technology for HEP Applications

The gigabit laser driver (GBLD) and low-power GBLD (LpGBLD) are two radiation-tolerant laser drivers designed to drive laser diodes at data rates up to 4.8 Gb/s. They have been designed in the framework of the gigabit-transceiver (GBT) and versatile-link projects to provide fast optical links capable of operation in the radiation environment of future high-luminosity high-energy physics experiments. The GBLD provides laser bias and modulation currents up to 43 mA and 24 mA, respectively. It can thus be used to drive vertical cavity surface emitting laser (VCSEL) and edge-emitting laser diodes. A pre-emphasis circuit, which can provide up to 12 mA in 70 ps pulses, has also been implemented to compensate for high external capacitive loads. The current driving capabilities of the LpGBLD are 2 times smaller that those of the GBLD as it has been optimized to drive VCSELs in order to minimize the power consumption. Both application-specific integrated circuits are designed in 0.13 m commercial complementary metal-oxide semiconductor technology and are powered by a single 2.5 V supply. The power consumption of the core circuit is 89 mW for the GBLD and 55 mW for the LpGBLD

Polyglandular autoimmune diseases in a dermatological clinical setting: vitiligo-associated autoimmune diseases

Vitiligo is an acquired hypomelanotic disorder characterized by depigmented macules resulting from the loss of functional melanocytes. Many different etiological hypotheses have been suggested for vitiligo, the most recent of which involves a combination of interacting environmental and genetic factors. Among the various pieces of evidence in support of an autoimmune origin of vitiligo, there is the epidemiological association with several autoimmune diseases. The most frequently reported association is with autoimmune thyroiditis; however, other diseases such as rheumatoid arthritis, diabetes mellitus, pernicious anemia and chronic urticaria have been described in variable percentages, depending upon the genetics of the population studied. Among the diseases described in association with vitiligo there are the so-called autoimmune polyglandular syndromes (APS). Here we report 31 cases of APS diagnosed in 113 vitiligo patients, according to the newest classification. Autoimmune association was more present in generalized non segmental vitiligo and was more frequent in females. The most frequent association was with thyroid autoimmune disease, followed by autoimmune gastritis and alopecia areata. ANA positivity was similar to that reported previously in the general population. We stress the importance of an assessment for autoimmune diseases in vitiligo patients

Dosimetry of microbeam radiotherapy by flexible hydrogenated amorphous silicon detectors

Objective. Detectors that can provide accurate dosimetry for microbeam radiation therapy (MRT) must possess intrinsic radiation hardness, a high dynamic range, and a micron-scale spatial resolution. In this work we characterize hydrogenated amorphous silicon detectors for MRT dosimetry, presenting a novel combination of flexible, ultra-thin and radiation-hard features. Approach. Two detectors are explored: an n-type/intrinsic/p-type planar diode (NIP) and an NIP with an additional charge selective layer (NIP + CSC). Results. The sensitivity of the NIP + CSC detector was greater than the NIP detector for all measurement conditions. At 1 V and 0 kGy under the 3T Cu-Cu synchrotron broadbeam, the NIP + CSC detector sensitivity of (7.76 ± 0.01) pC cGy−1 outperformed the NIP detector sensitivity of (3.55 ± 0.23) pC cGy−1 by 219%. The energy dependence of both detectors matches closely to the attenuation coefficient ratio of silicon against water. Radiation damage measurements of both detectors out to 40 kGy revealed a higher radiation tolerance in the NIP detector compared to the NIP + CSC (17.2% and 33.5% degradations, respectively). Percentage depth dose profiles matched the PTW microDiamond detector’s performance to within ±6% for all beam filtrations except in 3T Al-Al due to energy dependence. The 3T Cu-Cu microbeam field profile was reconstructed and returned microbeam width and peak-to-peak values of (51 ± 1) μm and (405 ± 5) μm, respectively. The peak-to-valley dose ratio was measured as a function of depth and agrees within error to the values obtained with the PTW microDiamond. X-ray beam induced charge mapping of the detector revealed minimal dose perturbations from extra-cameral materials. Significance. The detectors are comparable to commercially available dosimeters for quality assurance in MRT. With added benefits of being micron-sized and possessing a flexible water-equivalent substrate, these detectors are attractive candidates for quality assurance, in-vivo dosimetry and in-line beam monitoring for MRT and FLASH therapy

A Front-End Circuit in 28 nm CMOS for Hydrogenated Amorphous Silicon Detectors in Clinical Dosimetry

This paper presents the design and the characterization of a front-end circuit, designed in 28 nm CMOS, for real-time dosimetry in radiation diagnostics and radiation therapy. The front-end circuit is optimized for sensors made of hydrogenated amorphous silicon. The scheme is based on a current-to-frequency converter to sustain a large range of input currents. Three different programmable solutions have been investigated to be compatible with a wide variety of sensor sizes and applications. The front-end has been designed around three key specifications: an input capacitance between 1 pF and 50 pF, an input current from 100 pA to 2 mu A, and a measurement time ranging from 400 mu s to 60 ns. A first prototype has been fabricated and it is being characterized in laboratory