4,696 research outputs found
Belle II iTOP Optics: Design, Construction and Performance
The imaging-Time-of-Propogation (iTOP) counter is a new type of ring-imaging
Cherenkov counter developed for particle identification at the Belle II
experiment. It consists of 16 modules arranged azimuthally around the beam
line. Each module consists of one mirror, one prism and two quartz bar
radiators. Here we describe the design, acceptance test, alignment, gluing and
assembly of the optical components. All iTOP modules have been successfully
assembled and installed in the Belle II detector by the middle of 2016. After
installation, laser and cosmic ray data have been taken to test the performance
of the modules. First results from these tests are presented.Comment: Proceedings of TIPP 2017, May 22 - 26, Beijing, China, 2017;
University of Cincinnati preprint UCHEP-17-07. arXiv admin note: text overlap
with arXiv:1709.0993
Reconstruction of the Structure of Accretion Disks in Dwarf Novae from the Multi-Band Light Curves of Early Superhumps
We propose a new method to reconstruct the structure of accretion disks in
dwarf novae using multi-band light curves of early superhumps. Our model
assumes that early superhumps are caused by the rotation effect of
non-axisymmetrically flaring disks. We have developed a Bayesian model for this
reconstruction, in which a smoother disk-structure tends to have a higher prior
probability. We analyzed simultaneous optical and near-infrared photometric
data of early superhumps of the dwarf nova, V455 And using this technique. The
reconstructed disk has two flaring parts in the outermost region of the disk.
These parts are responsible for the primary and secondary maxima of the light
curves. The height-to-radius ratio is h/r=0.20-0.25 in the outermost region. In
addition to the outermost flaring structures, flaring arm-like patterns can be
seen in an inner region of the reconstructed disk. The overall profile of the
reconstructed disk is reminiscent of the disk structure that is deformed by the
tidal effect. However, an inner arm-like pattern, which is responsible for the
secondary minimum in the light curve, cannot be reproduced only by the tidal
effect. It implies the presence of another mechanism that deforms the disk
structure. Alternatively, the temperature distribution of the disk could be
non-axisymmetric. We demonstrate that the disk structure with weaker arm-like
patterns is optimal in the model including the irradiation effect. However, the
strongly irradiated disk gives quite blue colors, which may conflict with the
observation. Our results suggest that the amplitude of early superhumps depends
mainly on the height of the outermost flaring regions of the disk. We predict
that early superhumps can be detected with an amplitude of >0.02 mag in about
90% of WZ Sge stars.Comment: 17 pages, 17 figures, accepted for publication in PAS
Study on Electrode of Solid Electrolyte Hydrogen (Isotope) Sensor for Application to Liquid Blankets
- …