For instance, the long scans used in normal observing modes meant that the instrument spent 90% of the time completely off-fringe, leading to this observing inefficiency.
The ultimate test of the instrument's precision can be inferred from fitting calibrated visibilities obtained to the UD visibility function and analyzing the residuals obtained.
155 stars were observed sufficiently to consider, some of which are rather dim or might not be properly fit using a UD visibility function.
The better half of this set, 77 stars, all had a median residual which was better than 1.2% of the visibility itself.
The greatest attention is devoted to the single-mode fiber beam combiner (MONA) which is the heart of the instrument.
Nova Dissertation Tracking System Steps For Writing An Persuasive Essay
This device was an improved version of the tried and tested design used in the previous FLUOR instrument.a The Nu MI Off-axis $$\nu_e$$ Appearance (NOv A) experiment studies neutrino oscillations in the Nu MI (Neutrinos at the Main Injector) beam.The goal of the experiment is to determine the mass hierarchy and measure $$\delta_$$, however it is also sensitive to $$\sin\theta_$$, and $$\Delta m^2_$$.Unfortunately such attainable levels of precision were seldom realized due to the finite duration of observations.A number of conservative approaches in the design of VINCI helped guard against failure of the hardware or data analysis, however these also reduced the observational efficiency of the instrument.Recent enhancements to the proposed fringe tracker include selectable modes which detect only a single quadrature phase, both quadrature phases, or an uneven combination of the two.Optimization of partial spatial filtering using pinholes has been performed using a wavefront simulator and simulated tracking loop.The present work tries to improve experimental sensitivity to the oscillation parameters by considering neutrino events which are discarded by the previous analysis - escaping events.The biggest issues with the escaping sample are significant cosmic background and correct energy estimation.Both issues were addressed and inclusion of escaping sample to the final fit led to an effective increase of statistics by 4% with best- fit measurements of $$\sin\theta^2_ = 0.504$$ and $$\Delta m^2_ = 2.45 \times 10^$$ e V$^2$.The NOVA Fringe Tracker: a second generation cophasing facility for up to six telescopes at the VLTI Talk presented at SPIE conference 8445, Amsterdam, July 2012 View Abstract See also the paper submitted to SPIE, below.