1,722,228 research outputs found
The Dependence of Pulse-height On Anode Diameter and Gas-composition In Limited Streamer Tubes
No full textWe present some results of a study of charge spectra using plastic streamer tubes as a function of anode diameters and for an extensive selection of three component gas mixtures of argon,isobutane, and carbon dioxide. Chambers instrumented with longitudinal strip and pad readout were constructed with plastic streamer tubes using anode wires of one of six different diameters: 25, 50, 75, 100, 150, 200 mum. The six chambers were simultaneously triggered by cosmic-ray muons and the charge distributions were recorded for various voltages and gas mixtures. An unexpected scaling law may be at work during the transition to streamer mode
SIRAD: an irradiation facility at the LNL Tandem accelerator for radiation damage studies on semiconductor detectors and electronic devices and systems
No full textObservation of an energy dependence of the radiation damage on standard and oxygenated silicon diodes by 16-MeV, 21-MeV, and 27-MeV protons
No full textA SPICE model for Si microstrip detectors and read-out electronics
No full textWe have developed a SPICE model of silicon microstrip detector and its read-out electronics. The SPICE model of an AC-coupled single-sided polysilicon-biased silicon microstrip detector has been implemented by using a RC network containing up to 19 strips. The main parameters of this model have been determined by direct comparison with DC and AC measurements. The simulated interstrip and coupling impedance and phase angle are in good agreement with experimental results, up to a frequency of 1 MHz. We have used the PreShape 32 as our read-out chip for both the simulation and the measurements. It consists of a charge sensitive preamplifier followed by a shaper and a buffer. A current pulse, simulating the charge signal of an ionizing particle, has been applied to one end of a single strip. Its propagation along the strips and the read-out electronics has been experimentally studied and compared to the SPICE results in order to assess the quality of the model. The SPICE parameters have been adjusted to fit the experimental results obtained for the configuration where every strip is connected to the read-out electronics and kept the same for the different read-out configurations we have considered. By adding 2 further capacitances simulating the parasitic contributions between the read-out channels of the PS32 chip, a satisfactory matching between the experimental data and the simulated curves has been reached on both rising and trailing edges of the signal. Such agreement deteriorates only for strips far from the strip where the signal has been applied
Study of Punch-through Characteristics In Irradiated Mosfets
No full textThe DC and low frequency AC characteristics of the punch-through (PT) conduction have been examined in MOSFETs with different channel width/length ratios, fabricated on high resistivity Si substrates. The experimental results can be fitted by an analytical model deriving from a previous one developed for BARRITT devices. The modifications on the PT conduction induced by high dose neutron irradiation have been studied at various temperatures. The effects due to the radiation induced deep levels cannot be easily taken into account into the DC model, but can still be interpreted by using the AC model of the device
Breakdown of coupling dielectrics for Si microstrip detectors
No full textDouble-layer coupling dielectrics for AC-coupled Si microstrip detectors have been electrically characterized in order to determine their performance in a radiation-harsh environment, with a focus on the dielectric breakdown. Two different dielectric technologies have been investigated: SIO2/TEOS and SiO2/Si3N4. Dielectrics have been tested by using a negative gate voltage ramp of 0.2 MV/(cm.s). The metal/insulator/Si I-V characteristics show different behaviours depending on the technology. The extrapolated values of the breakdown field for unirradiated devices are significantly higher for SiO2/Si3N4 dielectrics, but the data dispersion is lower for SiO2/TEOS devices. No significant variation of the breakdown field has been measured after a 10 Mrad (Si) gamma irradiation for SiO2/Si3N4 dielectrics. Finally, the SiO2/Si3N4 DC conduction is enhanced if a positive gate voltage ramp is applied with respect to the negative one, due to the asymmetric conduction of the double-layer dielectric
Radiation effects on breakdown in silicon multiguarded diodes
No full textWe have investigated the current-voltage characteristics of silicon PIN diodes with a number of different multiguard structures. These structures were designed to increase the overall device breakdown voltage. The same measurements were carried out after gamma irradiation at different doses and neutron irradiation at fluences beyond type-inversion. This study is a first step towards defining guard structures optimized for operation in high-radiation environments such as those expected at the LHC
SPICE evaluation of the S/N ratio for Si microstrip detectors
No full textSPICE simulations of AC-coupled single-sided Si microstrip detectors connected to the Pre-Shape 32 read-out chip have been performed in order to determine the geometrical characteristics (i.e. the strip pitch p and width w) which maximize the signal-to-noise ratio at room temperature. All the resistive and capacitive elements of the detector have been determined as a function of the w/p ratio, by considering experimental and simulated data available in the literature. The SPICE model takes into account all the main noise sources in the detector and read-out electronics. The minimum ionizing particle current signal shape characteristics have been introduced in the simulations. Two read-out configurations (every strip or every second strip) have been investigated for 6.4 cm and 12.8 cm long detectors. Finally, general guidelines in the detector design have been proposed starting from the simulation results
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