19 research outputs found
Analysis of Organic Contamination in Gases using Non-Volatile Residue (NVR) Monitors and Time-of-Flight Secondary Ion Mass Spectrometry (Tof-Sims)
No full textABSTRACTA methodology has been developed which provides a means of detecting and
chemically characterizing low levels of contaminants in process gases used
in the microelectronics industry. NVR monitors based on SAW (surface
acoustical wave) technology were exposed to cylinders of a common gas used
in microelectronics applications. A control cylinder of clean N2
was compared with a deliberately contaminated cylinder and two supposedly
clean cylinders from different suppliers. The SAW devices were able to
detect the residue deposited from each gas. After exposure to the cylinders,
the SAW devices were directly analyzed by time-of-flight secondary ion mass
spectrometry (TOF-SIMS) to identify the deposited residues. The TOF-SIMS
instrument was equipped with a liquid-N2 cooled sample stage to
facilitate detection of semivolatile species in the UHV environment
necessary for the analysis.</jats:p
In situ analysis of organic monolayers and their reactivity on single micrometer-sized particles by time-of-flight secondary ion mass spectrometry
No full textDirect Surface Analysis of Organic Contamination for Semiconductor Related Materials
No full textABSTRACTDirect surface analysis of Si wafers and environmental materials such as polymers for wafer carriers and for high purity water systems is important to identify contaminants and their sources. Organic contaminants on the surfaces are difficult to analyze; however, their adverse effects have been cited in recent years. This paper demonstrates the detection and identification of surface contaminants using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) on semiconductor related materials. The analytical information provided by TOF-SIMS can be useful for maintaining material cleanliness or for failure analysis.</jats:p
Domestic Support Reform? A Closer Look at EU Policies Applied to Processed Fruits and Vegetables
No full textRecent trade negotiations have attracted much attention to the consequences of domestic support applied to agricultural markets. In various markets, researchers have examined the economic effects of regimes and scenarios with less, or different forms of, domestic support including decoupled payments. Here we examine the domestic support regimes for processed fruits and vegetables in the European Union (EU) where major policy changes were applied in 2001 and again in 2008. The changes were billed as policy “reform” but no analysis has yet evaluated quantitatively the nature of what was reformed and what was not. A simulation model is used here to assess the price, production, and welfare effects of policies that have been applied to the EU processing tomato industry. Our results indicate that EU domestic support has increased EU tomato production by 7 to 12%, decreased production in other regions by 3 to 5%, and distorted the processing tomato market most during the period between 2001 and 2007.agricultural policy reform, domestic support, horticultural markets, European Union, Common Agricultural Policy, processing tomatoes, simulation analysis, Agricultural and Food Policy, Q18,
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Data Acquisition System for the Large Scintillating Neutrino Detector at Los Alamos
No full textThe data acquisition system for the Large Scintillating Neutrino Detector (LSND) is described. The system collects time and charge information in real time from 1600 photomultiplier tubes and passes the data in intelligent-trigger selected time windows to analysis computers, where events are reconstructed and analyzed as candidates for a variety of neutrino-related physics processes. The system is composed of fourteen VME crates linked to a Silicon Graphics, Inc. 4D/480'' multiprocessor computer through multiple, parallel Ethernets, and a collection of contemporary high-performance workstations
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Data acquisition system for the Large Scintillating Neutrino Detector at Los Alamos
No full textThe data acquisition system for the Large Scintillating Neutrino Detector (LSND) is described. The system collects time and charge information in real time from 1600 photomultiplier tubes and passes the data in intelligent-trigger selected time windows to analysis computers, where events are reconstructed and analyzed as candidates for a variety of neutrino-related physics processes. The system is composed of fourteen VME crates linked to a Silicon Graphics, Inc. ``4D/480`` multiprocessor computer through multiple, parallel Ethernets, and a collection of contemporary high-performance workstations
Tests of Lorentz violation in ν̄μ→ν̄e oscillations
No full textA recently developed standard-model extension (SME) formalism for neutrino oscillations that includes Lorentz and CPT violation is used to analyze the sidereal time variation of the neutrino event excess measured by the liquid scintillator neutrino detector (LSND) experiment. The LSND experiment, performed at Los Alamos National Laboratory, observed an excess, consistent with neutrino oscillations, of ν̄e in a beam of ν̄μ. It is determined that the LSND oscillation signal is consistent with no sidereal variation. However, there are several combinations of SME coefficients that describe the LSND data; both with and without sidereal variations. The scale of Lorentz and CPT violation extracted from the LSND data is of order 10-19GeV for the SME coefficients aL and E×cL. This solution for Lorentz and CPT violating neutrino oscillations may be tested by other short baseline neutrino oscillation experiments, such as the MiniBooNE experiment. © 2005 The American Physical Society
Candidate events in a search for ν̄μ→ν̄e oscillations
No full textA search for ν̄e\u27s in excess of the number expected from conventional sources has been made using the Liquid Scintillator Neutrino Detector, located 30 m behind the Los Alamos Meson Physics Facility beam stop. The ν̄e are detected via ν̄e p→e+ n with e+ energy between 36 and 60 MeV, followed by a γ ray from np→dγ (2.2 MeV). Using strict cuts to identify γ rays correlated with e+ yields 9 events with only 2.1±0.3 background expected. A likelihood fit to the entire e+ sample results in a total excess of 16.4-8.9+9.7±3.3 events. If attributed to ν̄μ→ν̄e oscillations, this corresponds to an oscillation probability of (0.34-0.18+0.20±0.07)%. © 1995 The American Physical Society
Search for π\u3csup\u3e0\u3c/sup\u3e → vμv̄μ decays in the LSND detector
No full textThe production of beams from charged-current reaction of νμ and ν̄μ on C and H was investigated in liquid scintillator neutrino detector (LSND). The source for π0 was provided by 800-MeV beam of protons incident on water-copper target. Majority of triggers were induced by cosmic rays which were classified as through-going muons, electrons from stopping muon decays and recoil protons from neutron collisions. The spatial correlation between muons and the Michel electrons for beam-off, beam-on and beam-excess events was observed from visible energy distribution
