X-ray detectors for NDE applications

A tremendous development in the field of imaging radiation detectors has taken place in the last decade. Conventional X-ray film has been replaced by digital X-ray imaging systems in a no. of ways. Such systems mainly consist of silicon charge coupled devices (CCDs) where incident photons create electron-hole pairs in the thin silicon absorption layer near the surface. In contrast to visible light, which is absorbed within a 2 micro m layer of silicon, the penetration of X-ray is much deeper due to higher photon energy. This disadvantage is often circumvented by the use of a scintillator absorption layer. Due to scattering of the low energy fluorescence photons, resoln. and contrast of the X-ray images decrease. In order to eliminate these disadvantages, hybrid detectors consisting of direct converting semiconductors and readout electronics parts are fabricated. For this configuration, it is advantageous that both parts can be optimized sep. and different materials can be used. Because of the well developed technol., the readout chip is fabricated out of silicon. As absorbing material, silicon is less suitable. In a silicon substrate of 500 micro m thickness, only 15% of a 30 keV radiation is absorbed and converted into charges. In order to increase the absorption, materials with a higher at. mass have to be used. Several compd. semiconductors can be used for this purpose. One of them is GaAs, which is available as high quality semi-insulating wafer material. For detector optimization, GaAs wafers from several manufacturers with different properties were investigated. Test structures with Schottky and PIN diodes were fabricated. The I/V curves of the diodes, the spectral response from 5 up to 150 keV, the carrier concn., and the carrier mobility were measured and compared. A survey of the results and the criteria for material selection resulting from these measurements will be provided in the paper

Availability of Enabling Technologies for GaAs-Based Specific Applications

The key technological parameters for processing devices and IC’s based on epitaxial structures and semi-insulating GaAs are described. Technological potentialities for various specific applications (analog, digital, radiation detection) are demonstrated. Possible “niches” of technology implementation are discussed

Dual PD-1 and CTLA-4 Checkpoint Blockade Using Balstilimab and Zalifrelimab Combination as Second-Line Treatment for Advanced Cervical Cancer: An Open-Label Phase II Study

PURPOSE: Balstilimab (antiprogrammed death-1) and zalifrelimab (anticytotoxic T-lymphocyte-associated antigen-4) are two new checkpoint inhibitors emerging as promising investigational agents for the treatment of advanced cervical cancer. This phase II trial (ClinicalTrials.gov identifier: NCT03495882) evaluated the combination of balstilimab plus zalifrelimab in patients with recurrent and/or metastatic cervical cancer who relapsed after prior platinum-based therapy. PATIENTS AND METHODS: Patients were intravenously dosed with balstilimab 3 mg/kg once every 2 weeks and zalifrelimab 1 mg/kg once every 6 weeks, for up to 24 months. The primary end point was objective response rate (ORR, RECIST version 1.1, assessed by independent central review). Secondary end points included duration of response, safety and tolerability, and survival. RESULTS: In total, 155 women (median age, 50 years [range, 24-76 years]) were enrolled and treated with balstilimab plus zalifrelimab; 125 patients had measurable disease at baseline and one prior line of platinum-based therapy in the advanced setting, and these patients constituted the efficacy-evaluable population. The median follow-up was 21 months. The confirmed ORR was 25.6% (95% CI, 18.8 to 33.9), including 10 complete responders and 22 partial responders, with median duration of response not reached (86.5%, 75.5%, and 64.2% at 6, 9, and 12 months, respectively). The ORRs were 32.8% and 9.1% in patients with programmed death ligand-1-positive and programmed death ligand-1-negative tumors, respectively. For patients with squamous cell carcinoma, the ORR was 32.6%. The overall disease control rate was 52% (95% CI, 43.3 to 60.6). Hypothyroidism (14.2%) and hyperthyroidism (7.1%) were the most common immune-mediated adverse events. CONCLUSION: Promising and durable clinical activity, with favorable tolerability, was seen in this largest trial to date evaluating dual programmed death-1/cytotoxic T-lymphocyte-associated antigen-4 blockade in patients with recurrent and/or metastatic cervical cancer. Further investigation of the balstilimab and zalifrelimab combination in this setting is continuing.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

COMET Phase-I Technical Design Report

International audienceThe Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus (⁠|$\mu$|–|$e$| conversion, |$\mu^{-}N \rightarrow e^{-}N$|⁠); a lepton flavor-violating process. The experimental sensitivity goal for this process in the Phase-I experiment is |$3.1\times10^{-15}$|⁠, or 90% upper limit of a branching ratio of |$7\times 10^{-15}$|⁠, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the |$\mu$|–|$e$| conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described

Development of the CMS detector for the CERN LHC Run 3

A preprint version of this article is available at arXiv:2309.05466v1 [physics.ins-det], https://arxiv.org/abs/2309.05466v1 . Comments: Submitted to the Journal of Instrumentation. All figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/PRF-21-001 (CMS Public Pages). Report number: CMS-PRF-21-001, CERN-EP-2023-136.Since the initial data taking of the CERN LHC, the CMS experiment has undergone substantial upgrades and improvements. This paper discusses the CMS detector as it is configured for the third data-taking period of the CERN LHC, Run 3, which started in 2022. The entire silicon pixel tracking detector was replaced. A new powering system for the superconducting solenoid was installed. The electronics of the hadron calorimeter was upgraded. All the muon electronic systems were upgraded, and new muon detector stations were added, including a gas electron multiplier detector. The precision proton spectrometer was upgraded. The dedicated luminosity detectors and the beam loss monitor were refurbished. Substantial improvements to the trigger, data acquisition, software, and computing systems were also implemented, including a new hybrid CPU/GPU farm for the high-level trigger.SCOAP3