13,148 research outputs found
Sensor Simulation and position calibration for the CMS pixel detector
In this paper a detailed simulation of irradiated pixel sensors was used to
investigate the effects of radiation damage on charge sharing and position
determination. The simulation implements a model of radiation damage by
including two defect levels with opposite charge states and trapping of charge
carriers. We show that charge sharing functions extracted from the simulation
can be parameterized as a function of the inter-pixel position and used to
improve the position determination. For sensors irradiated to Phi=5.9x10^14
n/cm^2 a position resolution below 15 um can be achieved after calibration.Comment: Presented at the 14th Int. Workshop on Vertex Detectors (Vertex
2005), November 7-11 2005, Chuzenji Lake, Nikko, Japan. 4 pages, 1 figur
Boston University School of Medicine Alumni News
Newsletter for Boston University School of Medicine alumni
Statistical Uncertainties in Temperature Diagnostics for Hot Coronal Plasma Using the ASCA SIS
Statistical uncertainties in determining the temperatures of hot (0.5 keV to
10 keV) coronal plasmas are investigated. The statistical precision of various
spectral temperature diagnostics is established by analyzing synthetic ASCA
Solid-state Imaging Spectrometer (SIS) CCD spectra. The diagnostics considered
are the ratio of hydrogen-like to helium-like line complexes of
elements, line-free portions of the continuum, and the entire spectrum. While
fits to the entire spectrum yield the highest statistical precision, it is
argued that fits to the line-free continuum are less susceptible to atomic data
uncertainties but lead to a modest increase in statistical uncertainty over
full spectral fits. Temperatures deduced from line ratios can have similar
accuracy but only over a narrow range of temperatures. Convenient estimates of
statistical accuracies for the various temperature diagnostics are provided
which may be used in planning ASCA SIS observations.Comment: postscript file of 8 pages+3 figures; 4 files tarred, compressed and
uuencoded. To appear in the Astrophysical Journal Letters; contents copyright
1994 American Astronomical Societ
Some Choctaw sentence structures
From the introduction: Being somewhat familiar with Longacre\u27s case grammar approach to clause analysis, (Longacre, 1974), I felt it would be helpful to apply his sentence level techniques to the study of Choctaw. Longacre presents a binary, eight-part framework within which he groups all the various types of sentence combinations. [...] I chose to concentrate on the first four deep structures which find their counterparts in formal logic. Basically, conjoining and alternation are non-sequential deep structures while temporal and implication are sequential
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