ABSTRACT
A single-shot imaging system with multiple frames has been developed, which can record sequential multiple frames by delaying multiple optical images with fiber bundles and then capturing the images with a single intensified camera. The observed optical object is imaged through four lenses onto the end faces of four sets of fiber bundles. These fiber bundles with different lengths can provide different delays for delivering optical images, which determine the inter-frame separation times. The optical images exported from the fiber bundles are captured with a single intensified CMOS camera simultaneously. This imaging system has been applied for investigating the dynamic x-ray spot of the rod-pinch diode via a combination of scintillators, which are used to convert x-ray images to optical images. Four sequential x-ray images in a single shot have been obtained, which show the dynamic development of the rod-pinch x-ray spot. The results experimentally reveal the dynamics of the electrons flow bombarding the rod, which roughly agrees with the theoretical modeling of the rod-pinch diode.
ABSTRACT
An all-optical framing camera has been developed which measures the spatial profile of photons flux by utilizing a laser beam to probe the refractive index change in an indium phosphide semiconductor. This framing camera acquires two frames with the time resolution of about 1.5 ns and the inter frame separation time of about 13 ns by angularly multiplexing the probe beam on to the semiconductor. The spatial resolution of this camera has been estimated to be about 140 µm and the spectral response of this camera has also been theoretically investigated in 5 eV-100 KeV range. This camera has been applied in investigating the imploding dynamics of the molybdenum planar wire array Z-pinch on the 1-MA "QiangGuang-1" facility. This framing camera can provide an alternative scheme for high energy density physics experiments.
ABSTRACT
Modulation transfer function (MTF) is an important figure of image resolution of microchannel plate image intensifiers (MCPIIs). Dynamic MTFs of two Gen-II MCPIIs were measured under pulsed voltage operation (gated mode) using a narrow slit. The resolution determined by the MTF was calculated under various bias voltages and gate widths. Our numerical results show that with the increase of the reverse bias of MCPIIs, the resolution is improved rapidly below 40 V and then gradually decreased. With the MCP bias increased, both MCPIIs start to suffer rapid reductions in resolution at 800 and 750 V, respectively. The change of phosphor voltage has little influence on the resolution. The resolution declines rapidly with the decrease of the gate width below 20 ns but goes steady above 30 ns. We explored causes of these variations.
