Observing the reconnection region in a transequatorial loop system

A vertical current sheet is a crucial element in many flare/coronal mass ejection （CME） models. For the first time, Liu et al. reported a vertical current sheet directly imaged during the flare rising phase with the EUV Imaging Telescope （EIT） onboard the Solar and Heliospheric Observatory （SOHO）. As a follow-up study, here we present the comprehensive analysis and detailed physical interpretation of the observation. The current sheet formed due to the gradual rise of a transequatorial loop system. As the loop legs approached each other, plasma flew at - 6 km s^-1 into a local area where a cusp-shaped flare loop subsequently formed and the current sheet was seen as a bright, collimated structure of global length （_〉 0.25 RQ） and macroscopic width （（5-10）× 10^3 km）, extending from 50 Mm above the flaring loop to the border of the EIT field of view （FOV）. The reconnection rate in terms of the Alfven Mach number is estimated to be only 0.005-0.009, albeit a halo CME was accelerated from - 400 km s- 1 to - 1300 km s- 1 within the coronagraph FOV. Drifting pulsating structures at metric frequencies were recorded during the impulsive phase, implying tearing of the current sheet in the high corona. A radio Type III burst occurred when the current sheet was clearly seen in EUV, indicative of accelerated electrons beam- ing upward from the upper tip of the current sheet. A cusp-shaped dimming region was observed to be located above the post-flare arcade during the decay phase in EIT; both the arcade and the dimming expanded with time. With the Coronal Diagnostic Spectrometer （CDS） aboard SOHO, a clear signature of chromospheric evaporation was seen during the decay phase, i.e., the cusp-shaped dimming region was associ- ated with plasma upflows detected with EUV hot emission lines, while the post-flare loop was associated with downflows detected with cold lines. This event provides a comprehensive view of the reconnection geometry and dynamics in the solar corona.

A modified moire interferometer for three-dimensional displacement measurement

This paper presents a new optical interferometric system, MMI-T/G, composed of a modified four-beam moire interferometer and a Twyman/Green interferometer. The MMI-T/G system can measure three-dimensional displacement fringe patterns with a single loading on the specimen, and the in-plane and out-of-plane displacement fields can be measured independently and defined clearly. The optical setup has the advantages of structural novelty, flexibility, and high fringe contrast. Moreover, the in-plane displacement sensitivity is twice of that of the normal moire interferometer. The measuring techniques to obtain the fringe patterns and displacement fields using the MMI-T/G system are described. The experimental results of thermal displacement of an electronic device are shown.

REFRACTIVE INDEX AND APPARENT DENSITY OF THE EVAPORATED FILM OF COPPER PHTHALOCYANINE

As the film thickness is an important factor in the study of evaporated films, we have been looking for a convenient and nondestructive method of film thickness measurement. The infrared interferometric method which has been used for thickness measurement of the epitaxical growth of silicon, gives the optical thickness, i.e. the product of refractive index and thickness. In order to get the refractive index of αI-