130 research outputs found
Novel approaches to the construction of miniaturized analytical instrumentation
This paper focuses on the design, construction, preliminary testing, and potential applications of three forms of miniaturized analytical instrumentation. The first is an optical fiber instrument for monitoring pH and other cations in aqueous solutions. The instrument couples chemically selective indicators that were immobilized at porous polymeric films with a hardware package that provides the excitation light source, required optical components, and detection and data processing hardware. The second is a new form of a piezoelectric mass sensor. The sensor was fabricated by the deposition of a thin (5.5 micron) film of piezoelectric aluminum nitride (AIN). The completed deposition process yields a thin film resonator (TFR) that is shaped as a 400 micron square and supports a standing bulk acoustic wave in a longitudinal mode at frequencies of approx. 1 GHz. Various deposition and vapor sorption studies indicate that the mass sensitivity of the TFR's rival those of the most sensitive mass sensors currently available, though offering such performance in a markedly smaller device. The third couples a novel form of liquid chromatography with microlithographic miniaturization techniques. The status of the miniaturization effort, the goal of which is to achieve chip-scale separations, is briefly discussed
Search for Pauli Exclusion Principle Violating Atomic Transitions and Electron Decay with a P-type Point Contact Germanium Detector
A search for Pauli-exclusion-principle-violating K-alpha electron transitions
was performed using 89.5 kg-d of data collected with a p-type point contact
high-purity germanium detector operated at the Kimballton Underground Research
Facility. A lower limit on the transition lifetime of 5.8x10^30 seconds at 90%
C.L. was set by looking for a peak at 10.6 keV resulting from the x-ray and
Auger electrons present following the transition. A similar analysis was done
to look for the decay of atomic K-shell electrons into neutrinos, resulting in
a lower limit of 6.8x10^30 seconds at 90 C.L. It is estimated that the MAJORANA
DEMONSTRATOR, a 44 kg array of p-type point contact detectors that will search
for the neutrinoless double-beta decay of 76-Ge, could improve upon these
exclusion limits by an order of magnitude after three years of operation
Low Background Signal Readout Electronics for the MAJORANA DEMONSTRATOR
The MAJORANA DEMONSTRATOR is a planned 40 kg array of Germanium detectors
intended to demonstrate the feasibility of constructing a tonne-scale
experiment that will seek neutrinoless double beta decay () in
. Such an experiment would require backgrounds of less than 1
count/tonne-year in the 4 keV region of interest around the 2039 keV Q-value of
the decay. Designing low-noise electronics, which must be placed
in close proximity to the detectors, presents a challenge to reaching this
background target. This paper will discuss the MAJORANA collaboration's
solutions to some of these challenges
The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76
The {\sc Majorana} collaboration is searching for neutrinoless double beta
decay using Ge, which has been shown to have a number of advantages in
terms of sensitivities and backgrounds. The observation of neutrinoless
double-beta decay would show that lepton number is violated and that neutrinos
are Majorana particles and would simultaneously provide information on neutrino
mass. Attaining sensitivities for neutrino masses in the inverted hierarchy
region, meV, will require large, tonne-scale detectors with extremely
low backgrounds, at the level of 1 count/t-y or lower in the region of
the signal. The {\sc Majorana} collaboration, with funding support from DOE
Office of Nuclear Physics and NSF Particle Astrophysics, is constructing the
{\sc Demonstrator}, an array consisting of 40 kg of p-type point-contact
high-purity germanium (HPGe) detectors, of which 30 kg will be enriched
to 87% in Ge. The {\sc Demonstrator} is being constructed in a clean
room laboratory facility at the 4850' level (4300 m.w.e.) of the Sanford
Underground Research Facility (SURF) in Lead, SD. It utilizes a compact graded
shield approach with the inner portion consisting of ultra-clean Cu that is
being electroformed and machined underground. The primary aim of the {\sc
Demonstrator} is to show the feasibility of a future tonne-scale measurement in
terms of backgrounds and scalability.Comment: Proceedings for the MEDEX 2013 Conferenc
Status of the MAJORANA DEMONSTRATOR experiment
The MAJORANA DEMONSTRATOR neutrinoless double beta-decay experiment is
currently under construction at the Sanford Underground Research Facility in
South Dakota, USA. An overview and status of the experiment are given.Comment: 8 pages, proceeding from VII International Conference on
Interconnections between Particle Physics and Cosmology (PPC 2013), submitted
to AIP proceeding
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