1,514 research outputs found

    A high rate silicon detector and front-end electronics prototype for single ion discrimination in particle therapy

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    none18noThe medical physics group of the Turin section of the National Institute of Nuclear Physics, on the behalf of the MoVeIT collaboration, is working for the development of a new prototype of silicon strip detector for particle therapy applications. This device, based on 50 μm thin silicon sensors with internal gain, aims to detect the single beam particle and count their number up to 10 8 cm 2 /s fluxes, with a pileup probability <; 1%. A similar approach would lead to a drastic step forward, compared to the classical and widely used monitoring system based on ionization chambers. The better sensitivity, the higher dynamic range and the fact that the particle counting is independent of the beam energy, pressure and temperature, make this silicon detector suitable for the on-line dose monitoring in particle therapy applications. The prototype detector will cover a 3×3 cm 2 area and at the moment, two sets of strip sensors with different geometry and custom design, have been produced and are currently under investigation. The classic orthogonal strip positioning is used for beam profile measures. For what concerns the front-end electronics, the design of two different solutions is ongoing: one based on a transimpedance preamplifier, with a resistive feedback and the second one based on a charge sensitive amplifier. The challenging task for the design is the expected 3 fC - 130 fC wide input charge range (due to the Landau fluctuation spreading and different beam energies), dealing with a hundreds of MHz instantaneous rate (from 200 MHz up to 500 MHz ideally). To effectively design these components, it is crucial to perform preliminary investigation of the sensor response to the expected stimuli. For this reason an extensive work has been done and is still on going, using 1.2 mm 2 area and 50μm silicon pads with gain, performing test with the clinical beam of the Italian National Center of Oncological Hadrontherapy (CNAO) in Pavia, Italy.noneFausti, F.; Arcidiacono, R.; Attili, A.; Cartiglia, N.; Cenna, F.; Donetti, M.; Ferrero, M.; Giordanengo, S.; Hammad Ali, O.; Mandurrino, M.; Manganaro, L.; Monaco, V.; Mazza, G.; Sacchi, R.; Sola, V.; Staiano, A.; Vignati, A.; Cirio, R.Fausti, F.; Arcidiacono, R.; Attili, A.; Cartiglia, N.; Cenna, F.; Donetti, M.; Ferrero, M.; Giordanengo, S.; Hammad Ali, O.; Mandurrino, M.; Manganaro, L.; Monaco, V.; Mazza, G.; Sacchi, R.; Sola, V.; Staiano, A.; Vignati, A.; Cirio, R

    Tracking in 4 dimensions

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    In this contribution we review the progress towards the development of a novel type of silicon detectors suited for tracking with a picosecond timing resolution, the so called Ultra-Fast Silicon Detectors. The goal is to create a new family of particle detectors merging excellent position and timing resolution with GHz counting capabilities, very low material budget, radiation resistance, fine granularity, low power, insensitivity to magnetic field, and affordability. We aim to achieve concurrent precisions of ~ 10 ps and ~ 10 μm with a 50 μm thick sensor. The first part of this contribution explains the basic concepts of low-gain silicon sensors, while in the following the main results are presented, together with the efforts to make the design radiation resistance

    Beam test results of a 16 ps timing system based on ultra-fast silicon detectors

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    In this paper we report on the timing resolution of the first production of 50 micro-meter thick Ultra-Fast Silicon Detectors (UFSD) as obtained in a beam test with pions of 180 GeV/c momentum. UFSD are based on the Low-Gain Avalanche Detectors (LGAD) design, employing n-on-p silicon sensors with internal charge multiplication due to the presence of a thin, low-resistivity diffusion layer below the junction. The UFSD used in this test belongs to the first production of thin (50 {\mu}m) sensors, with an pad area of 1.4 mm2. The gain was measured to vary between 5 and 70 depending on the bias voltage. The experimental setup included three UFSD and a fast trigger consisting of a quartz bar readout by a SiPM. The timing resolution, determined comparing the time of arrival of the particle in one or more UFSD and the trigger counter, for single UFSD was measured to be 35 ps for a bias voltage of 200 V, and 26 ps for a bias voltage of 240 V, and for the combination of 3 UFSD to be 20 ps for a bias voltage of 200 V, and 15 ps for a bias voltage of 240 V.Comment: 7 pages, 8 figures, 1 table, Subm. to NIM

    Novel Vaccines to Human Rabies

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    Rabies, the most fatal of all infectious diseases, remains a major public health problem in developing countries, claiming the lives of an estimated 55,000 people each year. Most fatal rabies cases, with more than half of them in children, result from dog bites and occur among low-income families in Southeast Asia and Africa. Safe and efficacious vaccines are available to prevent rabies. However, they have to be given repeatedly, three times for pre-exposure vaccination and four to five times for post-exposure prophylaxis (PEP). In cases of severe exposure, a regimen of vaccine combined with a rabies immunoglobulin (RIG) preparation is required. The high incidence of fatal rabies is linked to a lack of knowledge on the appropriate treatment of bite wounds, lack of access to costly PEP, and failure to follow up with repeat immunizations. New, more immunogenic but less costly rabies virus vaccines are needed to reduce the toll of rabies on human lives. A preventative vaccine used for the immunization of children, especially those in high incidence countries, would be expected to lower fatality rates. Such a vaccine would have to be inexpensive, safe, and provide sustained protection, preferably after a single dose. Novel regimens are also needed for PEP to reduce the need for the already scarce and costly RIG and to reduce the number of vaccine doses to one or two. In this review, the pipeline of new rabies vaccines that are in pre-clinical testing is provided and an opinion on those that might be best suited as potential replacements for the currently used vaccines is offered

    Search for supersymmetry in events with photons and missing transverse energy in pp collisions at 13 TeV

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    Search for top squark pair production in pp collisions at root s=13 TeV using single lepton events

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