Optimization of light collection from crystal scintillators for cryogenic experiments

High light collection efficiency is an important requirement in any application of scintillation detectors. The purpose of this study is to investigate the possibility for improving this parameter in cryogenic scintillation bolometers, which can be considered as a promising detectors in experiments investigating neutrinoless double beta decay and dark matter. Energy resolutions and relative pulse amplitudes of scintillation detectors using ZnWO4 scintillation crystals of different shapes (cylinder 20 mm in dimater by 20 mm and hexagonal prism with diagonal 20 mm and height 20 mm), reflector materials and shapes, optical contact and surface properties (polished and diffused) were measured at room temperature. Propagation of optical photons in these experimental conditions was simulated using Geant4 and ZEMAX codes. The results of the simulations are found to be in good agreement with each other and with direct measurements of the crystals. This could be applied to optimize the geometry of scintillation detectors used in the cryogenic experiments.Comment: 12 pages, 8 figures, 1 Tabl

Impact of geometry on light collection efficiency of scintillation detectors for cryogenic rare event searches

Simulations of photon propagation in scintillation detectors were performed with the aim to find the optimal scintillator geometry, surface treatment, and shape of external reflector in order to achieve maximum light collection efficiency for detector configurations that avoid direct optical coupling, a situation that is commonly found in cryogenic scintillating bolometers in experimental searches for double beta decay and dark matter. To evaluate the light collection efficiency of various geometrical configurations we used the ZEMAX ray-tracing software. It was found that scintillators in the shape of a triangular prism with an external mirror shaped as truncated cone gives the highest light collection efficiency. The results of the simulations were confirmed by carrying out measurements of the light collection efficiencies of CaWO4 crystal scintillators. A comparison of simulated and measured values of light output shows good agreemen

Milnacipran in treatment of anxiety and depression conditions in patients with chronic dermatosis

The article describes an experience with Ixel (Milnacipran) medicine use in the treatment of anxiety and depression conditions in patients with chronic dermatosis. The results of an open clinical observation of Ixel use in the treatment of Psoriasis, Atopic Dermatitis, Rosacea and Eczema are presented. A detailed description is provided of the chronic dermatology disease diagnosis and condition evaluation scales that helped to prove the efficacy of Ixel. The medicine is recommended for usage in dermatology thanks to its safety, relatively low incidence of side effects and absence of complications.В данной работе описывается опыт применения препарата иксел (милнаципран) при лечении депрессивных состояний у больных с хроническими дерматозами. Приводятся результаты открытого клинического наблюдения данного препарата у больных с псориазом, атопическим дерматитом, розацеа, экземой. Подробно описаны оценочные шкалы диагностики состояний и хронических кожных заболеваний; с помощью этих шкал выявлена динамика состояний и оценена эффективность иксела. В связи с его безопасностью и сравнительно малым количеством побочных эффектов, отсутствием осложнений, препарат рекомендован для применения в дерматологии

New limits on 2ε2\varepsilon, εβ+\varepsilon\beta^+ and 2β+2\beta^+ decay of 136^{136}Ce and 138^{138}Ce with deeply purified cerium sample

A search for double electron capture ($2\varepsilon$), electron capture with positron emission ($\varepsilon\beta^+$), and double positron emission $2\beta^+$) in $^{136}$Ce and $^{138}$Ce was realized with a 465 cm$^3$ ultra-low background HP Ge $\gamma$ spectrometer over 2299 h at the Gran Sasso underground laboratory. A 627 g sample of cerium oxide deeply purified by liquid-liquid extraction method was used as a source of $\gamma$ quanta expected in double $\beta$ decay of the cerium isotopes. New improved half-life limits were set on different modes and channels of double $\beta$ decay of $^{136}$Ce and $^{138}$Ce at the level of $T_{1/2}>10^{17}-10^{18}$ yr.Comment: 19 pages, 6 figures, 2 table

Improvement of radiopurity level of enriched 116^{116}CdWO4_4 and ZnWO4_4 crystal scintillators by recrystallization

As low as possible radioactive contamination of a detector plays a crucial role to improve sensitivity of a double beta decay experiment. The radioactive contamination of a sample of $^{116}$CdWO$_4$ crystal scintillator by thorium was reduced by a factor $\approx 10$, down to the level 0.01 mBq/kg ($^{228}$Th), by exploiting the recrystallization procedure. The total alpha activity of uranium and thorium daughters was reduced by a factor $\approx 3$, down to 1.6 mBq/kg. No change in the specific activity (the total $\alpha$ activity and $^{228}$Th) was observed in a sample of ZnWO$_4$ crystal produced by recrystallization after removing $\approx 0.4$ mm surface layer of the crystal.Comment: 14 pages, 5 figures and 2 table

Possibilities of using computed tomography to treat mixed cervical dystonia with botulinum toxin type A

The paper describes a clinical case demonstrating the possibilities of using computed tomography (CT) in the diagnosis and treatment of botulinum toxin type A (BTA) treatment of mixed cervical dystonia (CD). The poor result of initial treatment is due to the fact that the abnormally active deep muscles of the neck were beyond the reach of injection. Routine clinical examination cannot identify a concurrence of the caput and collis types of CD in most cases, which occurred in our patient. Objective examination revealed displacement of the larynx to the left from the incisura thyroidea superior, which was characteristic of the left-sided rotational caput type of CD; however, CT detected mixed CD (a concurrence of torticollis and torticaput in the left). Cervical spine CT could visualize not only the superficial, but also deep dystonic muscles of the neck, specify a botulinum toxin therapy regimen, and estimate a difference in the volumes of the normal or dystonic inferior oblique muscle of the head with further intramuscular administration of botulinum toxin. The evaluation of the efficiency and safety of BTA therapy for this disease, as well as practical guidelines for the use of CT in the diagnosis and treatment of mixed CD are given

A clinical case of a patient with probable cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) from Chuvashia

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) syndrome is a congenital small-vessel disease running with recurrent lacunar infarcts and leading to gradually progressive subcortical, pseudobulbar, and cerebellar syndromes and dementia. Neuroimaging reveal multiple lacunar infarcts in the basal ganglia, thalamus, pons Varolii, and cerebral hemispheric white matter, as well as cerebral atrophy. The specific feature of the disease is white matter lesion adjacent to the temporal horns of the lateral ventricles and to the external capsules. The paper describes a patient with CADASIL syndrome. The latter runs a progressive course and includes the following neurological disorders: cognitive, pyramidal, extrapyramidal, and axial ones. This clinical case was differentially diagnosed with multiple sclerosis, including with consideration for neuroimaging findings. The CADASIL syndrome is a rare potentially menacing neurological condition that is observed in young patients and requires a detailed examination using current diagnostic techniques