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Further Investigations of Natural Environmental Radiation

Description: Report documenting the investigation of cosmic and terrestrial background radiation. "Remeasurements in many locations furnished estimates of dosimetric increase in terrestrial levels due to fallout. Radiation measurement sin residential dwellings in he New York metropolitan areas are described" (p. 1).
Date: November 3, 1959
Creator: Solon, Leonard R.; Lowder, Wayne M.; Shambon, Arthur & Blatz, Hanson
Partner: UNT Libraries Government Documents Department
open access

Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures

Description: We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.
Date: November 1, 2013
Creator: Alarcon, Ricardo; Balascuta, S.; Benson, Stephen V.; Bertozzi, William; Boyce, James R.; Cowan, Ray et al.
Partner: UNT Libraries Government Documents Department
open access

Some Variable Contributors to Natural Background

Description: It was suggested that radon concentrations in air and potassium fertilizers on the ground contribute appreciably to natural background radiation levels. The effect on natural background gamma radiation from radon and its associated daughters in equilibrium and from potassium in fertilizers has been calculated and found to be negligible. Background radiation intensities have been assumed to be on the order of 10 [mu]rad/hr.
Date: March 31, 1958
Creator: O'Brien, Keran
Partner: UNT Libraries Government Documents Department
open access

The Crosscorrelation Method of Measuring System Dynamic Response

Description: The basic relations of the crosscorrelation method are presented; and variations of the method for dealing with practical cases for which the idealized relations are inaccurate due to finite experiment length, finite bandwidth of the input signal, and uncorrelated noise in the system response signal are discussed and demonstrated. (D.C.W.)
Date: November 1, 1963
Creator: Balcomb, J. D.
Partner: UNT Libraries Government Documents Department
open access

Skyshine Contribution to Gamma Ray Background Between 0 and 4 MeV

Description: Natural gamma-ray background is composed of four components; which include cosmic rays, cosmic ray produced atmospheric activity, terrestrial sources, and skyshine from terrestrial sources. Skyshine is radiation scattered from the air above a source that can produce a signal in radiation detection instrumentation. Skyshine has been studied for many years but its contribution to the natural background observed in a detector has not been studied. A large NaI(Tl) detector was used to investigate each of the four components of the natural background using a series of 48-hour measurements and appropriate lead shielding configured to discriminate contributions from each component. It was found that while the contribution from skyshine decreases rapidly with energy, it represents a significant portion of the background spectrum below ~500keV. A similar campaign of measurements using a HPGe detector is underway.
Date: August 14, 2009
Creator: Mitchell, Allison L.; Borgardt, James D. & Kouzes, Richard T.
Partner: UNT Libraries Government Documents Department
open access

Majorana DUSEL R&D Final Report

Description: This report summarizes the work performed at PNNL under the project Majorana Neutrinoless Double Beta Decay DUSEL R&D over the period of FY07-FY09.
Date: September 21, 2010
Creator: Fast, James E.; Hoppe, Eric W.; Mintzer, Esther E.; Aalseth, Craig E.; Day, Anthony R.; Gerlach, David C. et al.
Partner: UNT Libraries Government Documents Department

Fontecilla mix II

Description: Recording of Andrés Lewin Richter's Fontecilla mix II. The piece is a reduction and organization of a 90-minute piece created to be MUZAK type background music -- mainly as climate manipulation rather than a sound poem -- for Chilean painter Ernesto Fontecilla's painting exhibition at Barcelona Galeria Trece in 1977. All material is electronic in origin.
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: 1978
Duration: 22 minutes 12 seconds
Creator: Lewin Richter, Andrés, 1937-
Partner: UNT Music Library
open access

Effects of Background Music on Preschoolers' Attention.

Description: Background music is often used in preschool classrooms with the belief that music makes children smarter and increases attention. The purpose of this study was to determine if background music increased children's focused attention during play activities. Focused attention occurs when children maintain attention to a task regardless of distractions. This quasiexperimental study investigated background music and play in a laboratory setting. I videotaped individual children during play with math manipulatives in a pretest-posttest research design with background music used as the treatment. Forty-three 3-, 4-, and 5-year-olds played for 15 minutes. The first 5 minutes of play had no music (pretest), the second 5-minute play episode had background music (treatment), and the final 5-minute play episode had no background music (posttest). Data were analyzed using one-way repeated measures analysis of variance. Findings revealed that the subjects paid less attention to the play task with background music than they did during the pretest, with no music. Another key finding was that children with more musical experiences at home, as reported by the Child's Home Musical Experience Survey (CHIMES), exhibited longer periods of focused attention with background music. This study confirmed previous research that 3-year-old children have shorter focused attention than 4- and 5-year-old children with and without background music. These findings have implications for teachers and parents that background music, instead of increasing attention in children, might indeed decrease children's focused attention during play activities.
Date: December 2009
Creator: Dartt, Kevin Maurine
Partner: UNT Libraries
open access

Theories of Auroras

Description: BS>The theories of the origin of the aurora are discussed from two points of view. The two basic structural types of auroras are described. A discussion is included of radio whistlers. (W.L.H.)
Date: April 1, 1959
Creator: Chamberlain, J.W.
Partner: UNT Libraries Government Documents Department
open access

Introduction to naturally occurring radioactive material

Description: Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from …
Date: August 1, 1997
Creator: Egidi, P.
Partner: UNT Libraries Government Documents Department
open access

MADmap: A Massively Parallel Maximum-Likelihood Cosmic Microwave Background Map-Maker

Description: MADmap is a software application used to produce maximum-likelihood images of the sky from time-ordered data which include correlated noise, such as those gathered by Cosmic Microwave Background (CMB) experiments. It works efficiently on platforms ranging from small workstations to the most massively parallel supercomputers. Map-making is a critical step in the analysis of all CMB data sets, and the maximum-likelihood approach is the most accurate and widely applicable algorithm; however, it is a computationally challenging task. This challenge will only increase with the next generation of ground-based, balloon-borne and satellite CMB polarization experiments. The faintness of the B-mode signal that these experiments seek to measure requires them to gather enormous data sets. MADmap is already being run on up to O(1011) time samples, O(108) pixels and O(104) cores, with ongoing work to scale to the next generation of data sets and supercomputers. We describe MADmap's algorithm based around a preconditioned conjugate gradient solver, fast Fourier transforms and sparse matrix operations. We highlight MADmap's ability to address problems typically encountered in the analysis of realistic CMB data sets and describe its application to simulations of the Planck and EBEX experiments. The massively parallel and distributed implementation is detailed and scaling complexities are given for the resources required. MADmap is capable of analysing the largest data sets now being collected on computing resources currently available, and we argue that, given Moore's Law, MADmap will be capable of reducing the most massive projected data sets.
Date: June 9, 2009
Creator: Cantalupo, Christopher; Borrill, Julian; Jaffe, Andrew; Kisner, Theodore & Stompor, Radoslaw
Partner: UNT Libraries Government Documents Department
open access

The Attenuation of Natural Environmental Radiation by an Automobile

Description: Report presenting a large number of measurements of natural environmental radiation in various parts of the United States using a 20-liter air filled polyethylene-walled ionization chamber at atmospheric pressure. The ionization current was measured with a vibrating reed electrometer connected as a continuously reading voltmeter driving a pen recorder" (p. 1).
Date: April 19, 1961
Creator: Shambon, Arthur; Lowder, Wayne M. & Solon, Leonard R.
Partner: UNT Libraries Government Documents Department
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