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An X.raj streak camera with an Xray streak tube used for laser-produced plasma soft Xrays measurement is described, and experimental results are given.
In investigating short-Jived high temperature plasma, and inertial control of
thermonuclear fusion in particular, measurement techniques based on registration of X-.rays emitted by the investigated object are of great value. They
make it possible to get much information on the dynamics of plasma evolution,
its form, dimensions, temperature, and density.
The instrumentation used for these purposes must meet the following main requirements:
it must provide measuring X-.rays time, intensity and spatial coordinate;
its spectral range must be wide, from relatively hard to extremely soft X-rays
(tens of keV to tens of eV quantum energy);
its tiive resolution must be high (of the order of 10 s).
At present the only type of an instrument satisfying the above requirements is
a streak camera with an X-ray' streak tube (X'RST).
The XRST operation principle has been known long ago: the photocathode converts the incident X-rays into an electron beam, which is accelerated and focused by the electric fields onto the output phosphor screen, where a visible
image of the incident radiation cross-.section appears. The image travels very
rapidly over the screen, resulting in a time sweep.
The design and development of such kind of instrumentation was begun in our
country more than 10 years ago. In 1986 the All-Union Research Institute of
experimental Physics, in collaboration with the Research Institute of Pulse
Technique, designed and built first instruments with satisfactory parameters.
These instruments found use in laser thermonuclear fusion research.
Mainly two types of X-.ray streak tubes are used for X-.ray spatial-temporal
structure registration:
special type X-ray streak tubes with X-ray sensitive photocathodes and transparent for X-ray input windows, and
X-ray streak tubes with X-ray sensitive photocathodes and without an input win
dow; these tubes are joined to a continuously pumped-out vacuum plant with an
X-ray source inside it. The quantum energy lower limit of the registered X-rays depends on the input
window thickness and. material, which determine its transparency for the radiation being investigated.
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