121182187
From ArgoNeuT to MicroBooNE
The final unknowns in the neutrino oscillation mixing matrix, including the search for CP Violation in the neutrino sector, offer extraordinary physics opportunities, which make a compelling case for developing the best possible detectors. Liquid Argon Time Projection Chambers (LArTPCs) combine fine-grained tracking with total absorption calorimetry to achieve sensitivities well beyond conventional neutrino detectors. The ArgoNeuT and MicroBooNE projects serve as steps in a development path towards massive kiloton scale LArTPCs for long baseline electron neutrino appearance physics. These experiments combine development goals with exploration of low energy neutrino interaction physics. Progress on ArgoNeuT and MicroBooNE en route to massive LArTPCs for the LBNE program are presented here.
118559630
Inner Structure and Outer Limits: Precision QCD and Electroweak Tests from Neutrino Experiments
121978152
Neutrino Scattering in Liquid Argon TPC Detectors
18440205
Photomultiplier tubes in the MiniBooNE experiment
The detector for the MiniBooNE [Proposal for the MiniBooNE experiment: hhttp://www-boone.fnal.gov/publicpages/proposal.psi] experiment at the Fermi National Accelerator Laboratory employs 1520 8 in. Hamamatsu models R1408 and R5912 photomultiplier tubes with custom-designed bases. Tests were performed to determine the dark rate, charge and timing resolutions, double-pulsing rate, and desired operating voltage for each tube, so that the tubes could be sorted for optimal placement in the detector. Seven phototubes were tested to find the angular dependence of their response. After the Super-K phototube implosion accident, an analysis was performed to determine the risk of a similar accident with MiniBooNE. r 2006 Elsevier B.V. All rights reserved.
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.
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.
119275441
Spitzer Mapping of PAHs and H2 in Photodissociation Regions
The mid-infrared (MIR) spectra of dense photodissociation regions (PDRs) are typically dominated by emission from polycyclic aromatic hydrocarbons (PAHs) and the lowest pure rotational states of molecular hydrogen (H2); two species which are probes of the physical properties of gas and dust in intense UV radiation fields. We utilize the high angular resolution of the Infrared Spectrograph on the Spitzer Space Telescope to construct spectral maps of the PAH and H2 features for three of the best studied PDRs in the galaxy, NGC 7023, NGC 2023 and IC 63. We present spatially resolved maps of the physical properties, including the H2 ortho-to-para ratio, temperature, and Go/nH . We also present evidence for PAH dehydrogenation, which may support theories of H2 formation on PAH surfaces, and a detection of preferential self-shielding of ortho-H2. All PDRs studied exhibit average temperatures of ∼ 500 – 800 K, warm H2 column densities of ∼ 10 cm, Go/nH ∼ 0.1 – 0.8, and ortho-to-para ratios of ∼ 1.8. We find that while the average of each of these properties is consistent with previous single value measurements of these PDRs, when available, the addition of spatial resolution yields a diversity of values with gas temperatures as high as 1500 K, column densities spanning ∼ 2 orders of magnitude, and extreme ortho-to-para ratios (ROP ) of ROP < 1 and ROP > 3. Subject headings: ISM:clouds — ISM: lines and bands — ISM: photon-dominated region — ISM: individual (NGC 7023, NGC 2023, IC 63) — ISM: molecules — infrared: ISM
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.