14637081
The Yale Lar TPC
In this paper we give a concise description of a liquid argon time projection chamber (Lar TPC) developed at Yale, and present results from its first calibration run with cosmic rays.
1526145
A regenerable filter for liquid argon purification
A filter system for removing electronegative impurities from liquid argon is described. The active components of the filter are adsorbing molecular sieve and activated-copper-coated alumina granules. The system is capable of purifying liquid argon to an oxygen-equivalent impurity concentration of better than 30 parts per trillion, corresponding to an electron drift lifetime of at least 10 ms. Reduction reactions that occur at �250 ◦ C allow the filter material to be regenerated in-situ through a simple procedure. In the following work we describe the filter design, performance, and regeneration process.
118559630
Inner Structure and Outer Limits: Precision QCD and Electroweak Tests from Neutrino Experiments
55097706
The Yale Liquid Argon Time Projection Chamber
In this paper we give a thorough description of a liquid argon time projection chamber designed, built and operated at Yale. We present results from a calibration run where cosmic rays have been observed in the detector, a first in the US.
110951547
Designs of Large Liquid Argon TPCs — from MicroBooNE to LBNE LAr40
Abstract Liquid argon time projection chamber (LArTPC) is a unique technology well suited for large scale detectors of neutrinos and other rare processes. Its combination of millimeter scale 3D precision particle tracking and calorimetry with good dE/dx resolution provide excellent efficiency of particle identification and background rejection. MicroBooNE is a LArTPC about to enter its final design phase and is scheduled for construction in 2012. Its active volume contains 86 ton of LAr. It has a 2.6m drift distance, 8256 sense wires connected to cold CMOS analog front–end electronics. Most of the TPC design features improve upon existing tried and true techniques. The LAr40 is one of the two far detector options under consideration for the Long Baseline Neutrino Experiment (LBNE). Its conceptual design has 40 kton active liquid argon mass, to be installed underground at a moderate depth. Due to its large scale, and underground siting, great emphasis was placed on the detector cost and reliability. A modular TPC design is the key to achieve these goals. The LAr40 consists of two 20 kton detectors in one underground cavern. Each detector is in turn constructed from an array of TPC modules. Innovative concepts enable the modules to be tiled with minimal dead space. An overview of both detectors is presented. The designs of key elements in these two TPCs are described in detail.
121978152
Neutrino Scattering in Liquid Argon TPC Detectors
5665227
Project Lyman
We explore the design of a space mission called Project Lyman that has the goal of quantifying the ionization history of th e universe from the present epoch to a redshift of z∼ 3. Observations from WMAP and SDSS show that before a redshif t of z∼> 6 the first collapsed objects, possibly dwarf galaxies, emit t d Lyman continuum (LyC) radiation shortward of 912 Å that reionized most of the universe. Theoretical estimates of the LyC escape fraction ( fesc) required from these objects to complete reionization isfesc∼ 10%. How LyC escapes from galactic environments, whether it induces positive or negative feedback on the local and global collapse of structures, and the role played by clumping, molecules, metallicity and dus t are major unanswered theoretical questions, requiring observ ational constraint. Numerous intervening Lyman limit syst ems frustrate the detection of LyC from high z objects. They thin below z∼ 3 where there are reportedly a few cases of apparently very highfesc. At low z there are only controversial detections and a handful of upp er limits. A wide-field multi-object spectroscopic survey with moderate spectral and spatial resolution can quantify esc within diverse spatially resolved galactic environments over redshifts with signifi cant evolution in galaxy assemblage and quasar activity. It can also calibrate LyC escape against Ly α escape, providing an essential tool to JWST for probing the b eginnings of reionization. We present calculations showing the evolution of the charac te istic apparent magnitude of star-forming galaxy lumino s ty functions at 900Å, as a function of redshift and assumed escape fraction. The se calculations allow us to determine the required aperture for detecting LyC and conduct trade studi es to guide technology choices and balance science return against mission cost. Finally we review our efforts to build a pathfinding dual order multi-object spectro/telescope wi th a (0.5◦)2 field-of-view, using a GSFC microshutter array, and crossed delay-line micro-channel plate detector.
1601826
Calibration and flight performance of the long-slit imaging dual order spectrograph
We present preliminary results for the calibration and flight performance of the Long-Slit Imaging Dual Order Spectrograph (LIDOS), a rocket-borne instrument with a large dynamic range in the 900 - 1650 Å bandpass. The instrument observes UV-bright objects with a CCD channel and fainter nebulosity with an MCP detector. The image quality and the detector quantum efficiencies were determined using the calibration and test equipment at the Johns Hopkins University, and further monitored using an on-board electron-impact calibration lamp. We review results from each of the three flights of the instrument.