A linear relationship between the luminosity on a phosphor plate and the electron number collected on it provides a highly sensitive diagnostics of two-dimensional density distribution with a wide dynamic range 10 to 60000 on 512x512 pixels. [1]
For a stable performance of the imaging diagnostics with new plasma trap operated under a high magnetic field up to 2.2T, a CCD camera must be moved by 1m apart from a viewing port of the trap vessel.
To maintain the brightness of the CCD images and the special resolution as obtained in old configuration, we have examined several candidates of the lens system for high-fidelity image transfer.Combining ray-tracing calculations and cross-checking experiments, we have come up to a zoom-type lens system.The new imaging system has been tested on the high magnetic field trap with a satisfactory quality of image data.

Here we report some examples demonstrating fine structures appearing in the electron vortex dynamics under the high magnetic field.
For coming experiments with the trap space-resolved energy spectra are regarded of high importance.
The energy analysis resorting to the flux measurement against the varied potential barrier at an end of the trap encounters a change in the plasma potential associated with the partial drain of trapped electrons.The plasma potential at the time of the draining is to be determined self-consistently and be included into the numerical processing for obtaining the energy spectra from the flux distribution as a CCD image as a function of the plug potential. [2]
As the second topic we report our present status in the effort of obtaining time-space resolved energy spectra.

References