Schematic of the experimental setup. Two Silicon p-n junction photodiodes and two pinhole cameras were often installed simultaneously on the radial ports to view the plasma in a single shot.
Typical current signals (with a quarter period of ) obtained with an integrated B-dot current probe placed in the midplane of the X pinch. The short circuit current is compared with the plasma current which typically crowbars after peak current. The B-dot signal was identical in time to the signal from a Rogowski coil placed around the ground electrode.
Time-integrated optical photographs of a tungsten X pinch obtained with different neutral density filters. The full anode-cathode gap can be seen. The anode is at the bottom.
Typical x-ray pinhole photographs and filter transmission curves. The cathode is at the top and the anode at the bottom in all images. (a) aluminum and (b) tungsten X pinches obtained with . The films were filtered with aluminized mylar which has a cutoff energy of about . The limbs can be seen almost down to the anode. (c) An example of a tungsten pinch observed with a pinhole and a Ti filter. (d) 4-wire titanium X pinch using a pinhole filtered with Ti and Be. A hot spot at the crossing point is often separated from bright spots located at the “heads” of the limbs. (e) aluminum filtered with Ti. A bright, almost circular hot spot is seen at the wire crossing point, suitable for point projection imaging.
X-ray radiographs of a common housefly imaged with (a) a constantan X pinch and (b) a molybdenum X pinch. Features as small as can be made out from such images, indicating a very small, well-defined, bright x-ray source.
An image from the slit-wire camera obtained with a constantan X pinch. The tungsten wire and the aluminum wire were placed in front of a slit located from the X pinch. The film was filtered with Ti and placed from the slit. The image shows clearly the shadows of both wires, indicating that the x-ray source size has an upper limit of .
Typical Silicon photodiode signals filtered with Be showing either single or multiple burst features. (a) Two-wire aluminum; (b) two-wire tungsten; and (c) four-wire titanium. A typical plasma current is included to illustrate the relative timing between the current pulse and the x-ray bursts.
Time sequence of interferograms showing the evolution of a tungsten X pinch obtained from different shots. The times indicated by are with respect to the of the current pulse; times indicated by are with respect to the onset of x-ray emission. In all images the cathode is at the top and the anode at the bottom.
Sequence of schlieren photographs showing the evolution of a tungsten X pinch obtained from different shots. The times indicated by are with respect to the time of peak x-ray emission; times indicated by are with respect to the onset of x-ray emission. The cathode is at the top and the anode at the bottom in all these images.
Aluminum resonance line and nearby satellite line obtained with a flat PET crystal spectrograph. The He-like intercombination line can also be seen.
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