Yu. Musienko

Super-sensitive avalanche silicon photodiode with surface transfer of charge carriers

New avalanche photodetector, combining properties of avalanche photodiode and charge coupled device was developed on the basis of MOSFET technology. The device employs the gain control and stabilization and is sensitive in visible and ultraviolet spectral regions. Experimental results with the new device are presented.

MRS detectors with high gain for registration of weak visible and UV light fluxes

Abstract Operation of silicon avalanche detectors based on a Metal-Resistive layer-Semiconductor (MRS) structure is presented. Results refer to a new batch of detectors fabricated on a n-type substrate especially made to be used as light detecting elements of a scintillating fiber detector for high energy physics applications. These detectors are meant for weak light fluxes in the range 200–600 nm (called UV MRS). Measurements of gain, noise and quantum efficiency were performed and operation of the detector at different temperatures was also studied.

Scintillator detectors with long WLS fibers and multi-pixel photodiodes

O. Mineev, ∗ Yu. Kudenko, Yu. Musienko, I. Polyansky, 2 and N. Yershov Institute for Nuclear Research of RAS Center of Perspective Technology and Apparatus,107076 Moscow, Russia Abstract We have studied the possibility of using Geiger mode multi-pixel photodiodes to read out long scintillator bars with a single wavelength-shifting fiber embedded along the bar. This detector configuration can be used in large volume detectors in future long baseline neutrino oscillation experiments. Prototype bars of 0.7 cm thickness and different widths have been produced and tested using two types of multi-pixel photodiodes: MRS APD (CPTA, Moscow) and MPPC (Hamamatsu). A minimum light yield of 7.2 p.e./MeV was obtained for a 4 cm wide bar.We have studied the possibility of using Geiger mode multi-pixel photodiodes to read out long scintillator bars with a single wavelength-shifting fiber embedded along the bar. This detector configuration can be used in large volume detectors in future long baseline neutrino oscillation experiments. Prototype bars of 0.7 cm thickness and different widths have been produced and tested using two types of multi-pixel photodiodes: MRS APD (CPTA, Moscow) and MPPC (Hamamatsu). A minimum light yield of 7.2 p.e./MeV was obtained for a 4 cm wide bar.

Scintillator counters with WLS fiber/MPPC readout for the side muon range detector (SMRD)of the T2K experiment

The T2K neutrino experiment at J-PARC uses a set of near detectors to measure the properties of an unoscillated neutrino beam and neutrino interaction cross-sections. One of the sub-detectors of the near-detector complex, the side muon range detector (SMRD), is described in the paper. The detector is designed to help measure the neutrino energy spectrum, to identify background and to calibrate the other detectors. The active elements of the SMRD consist of 0.7 cm thick extruded scintillator slabs inserted into air gaps of the UA1 magnet yokes. The readout of each scintillator slab is provided through a single WLS fiber embedded into a serpentine-shaped groove. Two Hamamatsu multi–pixel avalanche photodiodes (MPPCs) are coupled to both ends of the WLS fiber. This design allows us to achieve a high MIP detection efficiency of greater than 99%. A light yield of 25–50 p.e./MIP, a time resolution of about 1 ns and a spatial resolution along the slab better than 10 cm were obtained for the SMRD counters.

Highly sensitive micropixel avalanche photodiodes for scintillation counters of the T2K neutrino experiment

Highly sensitive micropixel avalanche photodiodes with a metal-resistor-semiconductor structure (MRS APDs) operating in the restricted Geiger discharge mode and scintillation detectors with wavelength-shifting optical fibers developed for the T2K neutrino oscillation experiment have been investigated. Dependencies of basic MRS APD parameters on the bias voltage, photon wavelength, and temperature have been measured. Characteristics of the scintillation detectors with wavelength-shifting optical fibers and avalanche photodiodes are described.

Fast beam chambers of the set-up ISTRA-M

Abstract The characteristics of narrow gap proportional chambers are presented. These chambers are applied in a beam part of the ISTRA-M apparatus in which very rare K − decays are studied.

Investigation of neutrino oscillations in the T2k long-baseline accelerator experiment

High-sensitivity searches for transitions of muon neutrinos to electron neutrinos are the main task of the T2K (Tokai-to-Kamioka) second-generation long-baseline accelerator neutrino experiment. The present article is devoted to describing basic principles of T2K, surveying experimental apparatuses that it includes, and considering in detail the muon-range detector (SMRD) designed and manufactured by a group of physicists from the Institute of Nuclear Research (Russian Academy of Sciences, Moscow). The results of the first measurements with a neutrino beam are presented, and plans for the near future are discussed.