Detection of Noble Gas Scintillation Light with Large Area Avalanche Photodiodes (LAAPDs)

Large Area Avalanche Photodiodes (LAAPDs) were used for a series of systematic measurements of the scintillation light in Ar, Kr, and Xe gas. Absolute quantum efficiencies are derived. Values for Xe and Kr are consistent with those given by the manufacturer. For the first time we show that argon scintillation (128 nm) can be detected at a quantum efficiency above 40%. Low-pressure argon gas is shown to emit significant amounts of non-UV radiation. The average energy expenditure for the creation of non-UV photons in argon gas at this pressure is measured to be below 378 eV.Comment: 16 pages, 7 figure

Preparation of Neutron-activated Xenon for Liquid Xenon Detector Calibration

We report the preparation of neutron-activated xenon for the calibration of liquid xenon (LXe) detectors. Gamma rays from the decay of xenon metastable states, produced by fast neutron activation, were detected and their activities measured in a LXe scintillation detector. Following a five-day activation of natural xenon gas with a Cf-252 (4 x 10^5 n/s) source, the activities of two gamma ray lines at 164 keV and 236 keV, from Xe-131m and Xe-129m metastable states, were measured at about 95 and 130 Bq/kg, respectively. We also observed three additional lines at 35 keV, 100 keV and 275 keV, which decay away within a few days. No long-lifetime activity was observed after the neutron activation.Comment: to be published in NIM A, corrected typos in Table 1 and Fig.6 of the previous versio

Thermodynamic modeling and experimental study of rice husk pyrolysis

Pyrolysis of agricultural waste is a promising route for waste to energy generation. Rice husk is a type of agro-waste that is available in plenty in India. It can be used as feed for pyrolysis to produce different products such as (solid) coke and silica, (liquid) tar and other organics and syngas. HSC Chemistry computer aided code for thermodynamic modeling was used to predict the products of rice-husk pyrolysis in this research study. The pyrolysis of rice husk was carried out between 100-1200°C in the pressure range of 1 – 15 bar. The pyrolysis products predicted by HSC calculations were mainly solid coke, gases like H2, CO2, CO, CH4, with small quantity of aromatic compounds like C6H6, C7H8, C8H10 (ethyl benzene), C8H10 (xylenes) and C6H5 –OH. An experimental study for product validation was also done and the results are presented

Faktor - Faktor Yang Berhubungan Dengan Gangguan Kesehatan Pada Pekerja Mebel Kayu Di Kelurahan Oesapa Kecamatan Kelapa Lima Kota Kupang

Workers of wood furniture are employes who are at risk for health issues. The issues are commonly caused by work-related condition. This study aimed to analyze the relationship between the length of work, use of Personal Protective Equipment (PPE), the period of working, type of job with health problems in wooden furniture workers in OesapaVillageKelapa Lima Sub-District Kupang 2017. Type of research used was analytical survey research with cross-sectional approach. This research was conducted in wooden furniture manufactures from March to June 2017. The population in this research was 55wooden furniture workers. Research sampling technique used was total sampling. Data was collected by questionnaire and interview. Data analysis technique used was chi-square test with significance level of α = 0,05. The results showed that the usage of PPE (0,00), type of work (0,00) were significantly related to health disorder at wooden furniture workers. There was no correlation observed between duration of work (0,54), period of working (0,92) and health disorder at wooden furniture workers

Absorption of Scintillation Light in a 100 ℓ\ell Liquid Xenonγ\gamma Ray Detector and Expected Detector Performance

An 800L liquid xenon scintillation $\gamma$ ray detector is being developed for the MEG experiment which will search for $\mu^+\to\mathrm{e}^+\gamma$ decay at the Paul Scherrer Institut. Absorption of scintillation light of xenon by impurities might possibly limit the performance of such a detector. We used a 100L prototype with an active volume of 372x372x496 mm$^3$ to study the scintillation light absorption. We have developed a method to evaluate the light absorption, separately from elastic scattering of light, by measuring cosmic rays and $\alpha$ sources. By using a suitable purification technique, an absorption length longer than 100 cm has been achieved. The effects of the light absorption on the energy resolution are estimated by Monte Carlo simulation.Comment: 18 pages, 10 figures (eps). Submitted to Nucl. Instr. and Meth.

Liquid Xenon Detectors for Positron Emission Tomography

PET is a functional imaging technique based on detection of annihilation photons following beta decay producing positrons. In this paper, we present the concept of a new PET system for preclinical applications consisting of a ring of twelve time projection chambers filled with liquid xenon viewed by avalanche photodiodes. Simultaneous measurement of ionization charge and scintillation light leads to a significant improvement to spatial resolution, image quality, and sensitivity. Simulated performance shows that an energy resolution of <10% (FWHM) and a sensitivity of 15% are achievable. First tests with a prototype TPC indicate position resolution <1 mm (FWHM).Comment: Paper presented at the International Nuclear Physics Conference, Vancouver, Canada, 201

Design and Performance of the XENON10 Dark Matter Experiment

XENON10 is the first two-phase xenon time projection chamber (TPC) developed within the XENON dark matter search program. The TPC, with an active liquid xenon (LXe) mass of about 14 kg, was installed at the Gran Sasso underground laboratory (LNGS) in Italy, and operated for more than one year, with excellent stability and performance. Results from a dark matter search with XENON10 have been published elsewhere. In this paper, we summarize the design and performance of the detector and its subsystems, based on calibration data using sources of gamma-rays and neutrons as well as background and Monte Carlo simulations data. The results on the detector's energy threshold, energy and position resolution, and overall efficiency show a performance that exceeds design specifications, in view of the very low energy threshold achieved (<10 keVr) and the excellent energy resolution achieved by combining the ionization and scintillation signals, detected simultaneously

Experimental Study of CO2 Gasification of Biomethanation Waste

Gasification is one of prominent thermochemical processes generally used to convert organic feedstock to combustible syngas (CO and H2). An experimental study of biomass gasification using carbon dioxide as an gasifying medium was carried out in a fixed bed gasifier. The main aim of this study was to determine the effect of temperature on the output syngas. The present study reported the results for producing syngas with CO2 as gasification agent and biomass (rice husk and bio-methanation waste) as raw material. The gasification was performed at 700-900°C respectively and CO2 flow rate was maintained at 0.5 lpm. Maximum syngas production found at high temperature (900°C). The syngas analysis showed higher hydrogen yield at higher temperatures

Experimental study of effect of pressure on pyrolysis of biomass

Pyrolysis is thermal treatment of solid waste in the absence of an oxidizing agent (in inert atmosphere) which generally yields three products namely pyrolysis-oil (liquid), char (solid residue) and gas. The products obtained in pyrolysis can be further used as energy source. Rice husk and saw dust are considered as solid wastes in this study. The effect of temperature and pressure on pyrolysis was studied in a fixed bed reactor. The experimental runs were performed in nitrogen atmosphere. The temperature was varied from 300°C to 500°C, while the operational pressure was fixed at 4 bar, 7 bar and 10 bar. The products such as solid char, liquid pyrolysis oil and syngas were obtained. The solid char was characterized by CHNS analysis, while the pyrolysis oil was characterized by FTIR analysis