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

Influence of Addition of Previously Fermented Juice to Alfalfa Ensiled at Different Moisture Contents

Alfalfa (Medicago sativa L.)was ensiled with or without previously fermented juice (PFJ) after wilting for 0, 3, 6 and 24 h. They were ensiled in 900ml glass bottles at 400g/800cm3 and preserved at 25°C for 45 d. The moisture content of the silages were 810, 730, 690 and 580g/kg, respectively. The PFJ was prepared by macerating 200g of freshly harvested alfalfa with 1,000ml of water, filtering through double cheese cloth, adding 20g/l sucrose and incubating anaerobically at 30°C for 2 d. They were added 2.5ml/kg of chopped alfalfa. Lactic acid fermentation of silage was enhanced bAlfalfa (Medicago sativa L.) was ensiled with or without previously fermented juice (PFy the addition of PFJ at every moisture content studied. Without additive, the pH of silages containing 810, 730, 690 and 580g moisture/kg were 4.95, 4.67, 5.26 and 5.50, respectively, while they were 4.42, 4.45, 4.53 and 4.72, respectively, in PFJ silages. This suggests that a high pH observed in wilted silage partially due to a lack of lactic acid bacteria (LAB) and addition of PFJ at ensiling provides enough LAB to lower it. PFJ was also effective in depressing clostridial fermentation at the moisture contents where butyric acid was found without it