10 research outputs found

    Performance of the Electromagnetic Pixel Calorimeter Prototype EPICAL-2

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    The first evaluation of an ultra-high granularity digital electromagnetic calorimeter prototype using 1.0-5.8 GeV/c electrons is presented. The 25×10625\times10^6 pixel detector consists of 24 layers of ALPIDE CMOS MAPS sensors, with a pitch of around 30~μ\mum, and has a depth of almost 20 radiation lengths of tungsten absorber. Ultra-thin cables allow for a very compact design. The properties that are critical for physics studies are measured: electromagnetic shower response, energy resolution and linearity. The stochastic energy resolution is comparable with the state-of-the art resolution for a Si-W calorimeter, with data described well by a simulation model using GEANT and Allpix2^2. The performance achieved makes this technology a good candidate for use in the ALICE FoCal upgrade, and in general demonstrates the strong potential for future applications in high-energy physics.Comment: 30 pages, 19 figures, submitted to JINS

    Performance of the electromagnetic pixel calorimeter prototype Epical-2

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    The first evaluation of an ultra-high granularity digital electromagnetic calorimeter prototype using 1.0-5.8 GeV/c electrons is presented. The 25 × 106 pixel detector consists of 24 layers of ALPIDE CMOS MAPS sensors, with a pitch of around 30 μm, and has a depth of almost 20 radiation lengths of tungsten absorber. Ultra-thin cables allow for a very compact design. The properties that are critical for physics studies are measured: electromagnetic shower response, energy resolution and linearity. The stochastic energy resolution is comparable with the state-of-the art resolution for a Si-W calorimeter, with data described well by a simulation model using Geant4 and Allpix2. The performance achieved makes this technology a good candidate for use in the ALICE FoCal upgrade, and in general demonstrates the strong potential for future applications in high-energy physics

    Implementation quality of principles of reciprocal teaching in whole-classroom settings: A two-year study with low-achieving adolescents

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    Low-achieving adolescents are known to have difficulties with reading comprehension. This article discusses whether principles of reciprocal teaching can improve low-achieving adolescents' reading comprehension in whole-classroom settings and to what extent treatment effects are dependent on implementation quality. Over the course of two years, experimental teachers (n = 10) were given training and coaching aimed at using principles of reciprocal teaching, while control teachers (n = 10) used their regular teaching method. Observations of teacher implementation were focused on instruction of reading strategies, modeling, and support of group work, and were performed in both experimental and control classes, comprising a total of 238 students (grade 7). The study shows that overall, there is no effect of the treatment on adolescent low-achievers' reading comprehension. Interestingly however, the principle of modeling positively moderated the effect of reciprocal teaching In addition, results suggest that the quality of implementation of reciprocal teaching in whole-classroom settings should receive more attention

    Neutron Fluence Spectrometry Using Disk Activation

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    A simple and robust detector for spectrometry of environmental neutrons has been developed. The technique is based on neutron activation, i.e. the activation of a series of different metal disks followed by gamma-ray spectrometry of the activated disks and subsequent neutron spectrum unfolding. It is a technique similar to the foil activation but now applied to low neutron fluence rates. The detector has been tested in quasi mono-energetic neutron fields where the obtained spectra showed good agreement with spectra measured using a Bonner sphere spectrometer. The detector has also been tested by means of an AmBe source and, again, a good agreement with the assumed spectrum was achieved. Low-level and ultra-low level gamma spectrometry allowed for the measurements of very low neutron fluences with detection limits for fast neutrons in the order of 10 s-1 cm-2.JRC.D.5-Neutron physic

    Long-term follow-up of follicular lymphoma (FL) patients receiving single agent rituximab at two different schedules in trial SAKK 35/98

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    Background: In FL, Rituximab as a single agent delivered in the standard schedule (4 times weekly) may induce a response rate of 50−70% with an event-free survival (EFS) of 1−3 years according to patients' characteristics. Prolonged Rituximab exposure seems to improve EFS at least in responding patients and to increase the rate of longterm responders. Here we report long-term results of a clinical trial comparing single agent Rituximab delivered in the standard schedule versus prolonged exposure, with focus on the proportion of long-term responders and their characteristics. Material and Methods: Between 1998 and 2002, chemotherapy na¨ıve (n = 64) or pre-treated (n = 138) FL patients received Rituximab in the standard schedule. Those responding or with stable disease were randomized to no further treatment (observation, n = 78) or 4 additional doses of Rituximab given at 2-month intervals (prolonged exposure, n = 73). EFS was calculated from the first dose of standard schedule until progression, relapse, second tumor or death. Results: At a median follow up of 9.4 years and with all living patients having been followed for at least 5 years, the median EFS is 13 months for the observation and 24 months for the prolonged exposure arm (p = 0.0007). In the observation arm 13% had no event at 5-years and only 4% at 8 years, while in the prolonged exposure arm it was 27% at 5 years and remained 21% at 8 years. The only significant prognostic factor for EFS in a multivariate Cox regression was the prolonged Rituximab schedule (hazard ratio 0.58, CI 0.39−0.86, p = 0.007), whereas being chemotherapy na¨ıve, presenting with stage <IV and showing a VV phenotype at position 158 of the Fc receptor RIIIA were not of significant prognostic value. No long-term toxicity from treatment was observed. There were 22 cases of second malignancy: 12 on observation, 10 on prolonged exposure. 5 patients developed myelodysplastic syndrome; all received previous chemotherapy treatment. Conclusions: Our results confirm that the prolonged exposure to Rituximab significantly improves EFS as compared to the standard schedule. This benefit continues for many years after the end of therapy and the prolonged exposure seems to be the sole factor which may be considered of prognostic value. Patients treated with prolonged schedule (8 doses of Rituximab) may have approximately 25% and 20% chances to be in remission at 5 and 8 years respectively and to avoid subsequent chemotherapy treatment

    Long-term follow-up of patients with follicular lymphoma receiving single-agent rituximab at two different schedules in trial SAKK 35/98

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    PURPOSE: We report the long-term results of a randomized clinical trial comparing induction therapy with once per week for 4 weeks single-agent rituximab alone versus induction followed by 4 cycles of maintenance therapy every 2 months in patients with follicular lymphoma. PATIENTS AND METHODS: Patients (prior chemotherapy 138; chemotherapy-naive 64) received single-agent rituximab and if nonprogressive, were randomly assigned to no further treatment (observation) or four additional doses of rituximab given at 2-month intervals (prolonged exposure). RESULTS: At a median follow-up of 9.5 years and with all living patients having been observed for at least 5 years, the median event-free survival (EFS) was 13 months for the observation and 24 months for the prolonged exposure arm (P < .001). In the observation arm, patients without events at 8 years were 5%, while in the prolonged exposure arm they were 27%. Of previously untreated patients receiving prolonged treatment after responding to rituximab induction, at 8 years 45% were still without event. The only favorable prognostic factor for EFS in a multivariate Cox regression was the prolonged rituximab schedule (hazard ratio, 0.59; 95% CI, 0.39 to 0.88; P = .009), whereas being chemotherapy naive, presenting with stage lower than IV, and showing a VV phenotype at position 158 of the Fc-gamma RIIIA receptor were not of independent prognostic value. No long-term toxicity potentially due to rituximab was observed. CONCLUSION: An important proportion of patients experienced long-term remission after prolonged exposure to rituximab, particularly if they had no prior treatment and responded to rituximab induction

    Performance of the electromagnetic pixel calorimeter prototype Epical-2

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    The first evaluation of an ultra-high granularity digital electromagnetic calorimeter prototype using 1.0-5.8 GeV/c electrons is presented. The 25 × 106 pixel detector consists of 24 layers of ALPIDE CMOS MAPS sensors, with a pitch of around 30 μm, and has a depth of almost 20 radiation lengths of tungsten absorber. Ultra-thin cables allow for a very compact design. The properties that are critical for physics studies are measured: electromagnetic shower response, energy resolution and linearity. The stochastic energy resolution is comparable with the state-of-the art resolution for a Si-W calorimeter, with data described well by a simulation model using Geant4 and Allpix2. The performance achieved makes this technology a good candidate for use in the ALICE FoCal upgrade, and in general demonstrates the strong potential for future applications in high-energy physics

    Results from the EPICAL-2 ultra-high granularity electromagnetic calorimeter prototype

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    A prototype of a new type of calorimeter has been designed and constructed, based on a silicon–tungsten sampling design using pixel sensors with digital readout. It makes use of the ALPIDE sensor developed for the ALICE Inner Tracking System (ITS) upgrade. A binary readout is possible due to the pixel size of ≈30×30μm2. This prototype has been successfully tested with cosmic muons and with test beams at DESY and the CERN SPS. We report on performance results obtained at DESY, showing good energy resolution and linearity, and compare to detailed MC simulations. Also shown are preliminary results of the high-energy performance as measured at the SPS. The two-shower separation capabilities are discussed

    Results from the EPICAL-2 Ultra-High Granularity Electromagnetic Calorimeter Prototype

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    A prototype of a new type of calorimeter has been designed and constructed, based on a silicon-tungsten sampling design using pixel sensors with digital readout. It makes use of the Alpide MAPS sensor developed for the ALICE ITS upgrade. A binary readout is possible due to the pixel size of 30×30μm2\approx 30 \times 30 \, \mu \mathrm{m}^2. This prototype has been successfully tested with cosmic muons and with test beams at DESY and the CERN SPS. We report on performance results obtained at DESY, showing good energy resolution and linearity, and compare to detailed MC simulations. Also shown are preliminary results of the high-energy performance as measured at the SPS. The two-shower separation capabilities are discussed.Comment: Proceedings to PM2021 - The 15. PISA Meeting on Advanced Detector
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