Status of the Lake Baikal Experiment

We review the present status of the Baikal Underwater Neutrino Experiment and report on neutrino events recorded with the detector stages NT-36 and NT-96.Comment: 5 pages, 4 PostScript figures, uses here.sty and mine.sty, submitted to the Proc. of 5th Int. Workshop on Topics in Astroparticle and Underground Physics (LNGS INFN, Assergi, September 7-11, 1997

Registration of atmospheric neutrinos with the Baikal neutrino telescope

We present first neutrino induced events observed with a deep underwater neutrino telescope. Data from 70 days effective life time of the BAIKAL prototype telescope NT-96 have been analyzed with two different methods. With the standard track reconstruction method, 9 clear upward muon candidates have been identified, in good agreement with 8.7 events expected from Monte Carlo calculations for atmospheric neutrinos. The second analysis is tailored to muons coming from close to the opposite zenith. It yields 4 events, compared to 3.5 from Monte Carlo expectations. From this we derive a 90 % upper flux limit of 1.1 * 10^-13 cm^-2 sec^-1 for muons in excess of those expected from atmospheric neutrinos with zenith angle > 150 degrees and energy > 10GeV.Comment: 20 pages, 11 figure

Radiation hardness of AlAs/GaAs-based resonant tunneling diodes

The total dose effects of ⁶⁰Co γ-radiation on the electrical properties of double-barrier Resonant Tunneling Diodes have been studied. The devices manifest enhanced radiation hardness and conserve their operating parameters up to doses of 2×10⁹ rad. It is shown that all changes in the current-voltage characteristics stem from the effect of ionizing radiation on the undoped layers. The radiation-stimulated diffusion of the heteropair components in the contact region is shown to be important for the voltage drop distribution

Effect of rapid thermal annealing on properties of contacts Au-Mo-TiBx-GaAs

The analytical, structural and electrophysical techniques have been applied to studies of the thermal degradation mechanism appearing in diode structures with the Schottky barrier Au-Mo-TiBxGaAs. It was shown that the rapid thermal annealing at T = 600 °C during 60 sec in hydrogen atmosphere results in creating the ELS type center in the space charge region of GaAs. This center is represented by the complex VGa+VAs, which has been confirmed by photoluminescence measurements. It causes the appearance of excess current at the initial part of current-voltage characteristic

The Lake Baikal neutrino experiment

We rewiew the present status of the Baikal Neutrino Project and present the results of a search for high energy neutrinos with the detector intermediate stage NT-96.Comment: 3 pages, 2 figures, to appear in the Proceedings of Sixth International Workshop on Topics in Astroparticle and Underground Physics (TAUP99), September 6-10, 1999, Pais, Franc

The Baikal Deep Underwater Neutrino Experiment: Results, Status, Future

We review the present status of the Baikal Underwater Neutrino Experiment and present results obtained with the various stages of the stepwise increasing detector: NT-36 (1993-95), NT-72 (1995-96) and NT-96 (1996-97). Results cover atmospheric muons, first clear neutrino events, search for neutrinos from WIMP annihilation in the center of the Earth, search for magnetic monopoles, and -- far from astroparticle physics -- limnology.Comment: Talk given at the Int. School on Nuclear Physics, Erice, Sept.199

Baikal-GVD

We present the status of the Gigaton Volume Detector in Lake Baikal (Baikal-GVD) designed for the detection of high energy neutrinos of astrophysical origin. The telescope consists of functionally independent clusters, sub-arrays of optical modules (OMs), which are connected to shore by individual electro-optical cables. During 2015 the GVD demonstration cluster, comprising 192 OMs, has been successfully operated in Lake Baikal. In 2016 this array was upgraded to baseline configuration of GVD cluster with 288 OMs arranged on eight vertical strings. Thus the instrumented water volume has been increased up to about 5.9 Mtons. The array was commissioned in early April 2016 and takes data since then. We describe the configuration and design of the 2016 array. Preliminary results obtained with data recorded in 2015 are also discussed

Effect of microwave treatment on current flow mechanisms in Au-TiBx-Al-Ti-n(+)-n-n(+)-GaN-Al2O3 ohmic contacts

The temperature dependences of the contact resistivity rho(c) of Au-TiBx Al-Ti-n(+)-n-n(+)-GaN-Al2O3 ohmic contacts have been studied before and after microwave treatment followed by nine-nonth room-temperature sample storage. The temperature dependences of rho(c) of initial samples were measured twice. The first measurement showed the temperature dependence typical of ohmic contacts; the repeated measurement in the temperature region above 270 K showed a rho(c) increase caused by metallic conductivity. After microwave treatment, the metallic conductivity in the ohmic contact is not observed. This is presumably associated with local heating of metal Ga inclusions under microwave irradiation and the formation, due to high chemical activity of liquid gallium, of compounds of it with other metallization components. In this case, the temperature dependence of rho(c) is controlled by ordinary charge transport mechanisms. After nine-nonth room-temperature storage, the temperature dependence of ?c is described by the tunneling mechanism of charge transport

Aerobic Co or Cu/NHPI-catalyzed oxidation of hydride siloxanes: Synthesis of siloxanols

A highly efficient preparative method for the synthesis of siloxanols based on aerobic Co(OAc)2 or Cu(OAc)2/NHPI-catalyzed oxidation of hydride siloxanes using "green", commercially available, simple inexpensive reagents and mild reaction conditions has been proposed. This is a general reaction for the synthesis of mono-, oligo- and polymeric siloxanols with various structures (linear, branched and cyclic). © 2018 The Royal Society of Chemistry