Application of PM-355 Solid-State Nulear Track Detectors for ion diagnostics in high-temperature plasma experiments

Update on the Scientific Status of the Plasma Focus

This paper is a sequel to the 1998 review paper “Scientific status of the Dense Plasma Focus” with 16 authors belonging to 16 nations, whose initiative led to the establishment of the International Center for Dense Magnetized Plasmas (ICDMP) in the year 2000. Its focus is on understanding the principal defining characteristic features of the plasma focus in the light of the developments that have taken place in the last 20 years, in terms of new facilities, diagnostics, models, and insights. Although it is too soon to proclaim with certainty what the plasma focus phenomenon is, the results available to date conclusively indicate what it is demonstrably not. The review looks at the experimental data, cross-correlated across multiple diagnostics and multiple devices, to delineate the contours of an emerging narrative that is fascinatingly different from the standard narrative, which has guided the consensus in the plasma focus community for several decades, without invalidating it. It raises a question mark over the Fundamental Premise of Controlled Fusion Research, namely, that any fusion reaction having the character of a beam-target process must necessarily be more inefficient than a thermonuclear process with a confined thermal plasma at a suitably high temperature. Open questions that need attention of researchers are highlighted. A future course of action is suggested that individual plasma focus laboratories could adopt in order to positively influence the future growth of research in this field, to the general benefit of not only the controlled fusion research community but also the world at large.

A single-ion monitor based on coincident measurement of secondary electrons for single event effect research

Single-ion monitoring is a key requirement for many energetic heavy-ion experiments, e.g., the laboratory simulation of the single event effect of semiconductor devices under heavy ion bombardments. We have developed a two-dimensional position-sensitive and timing monitor of individual ions. It is composed of a thin aluminum foil, a pair of microchannel plate detectors, and electrostatic and magnetic fields. When energetic heavy ions pass through the aluminum foil, secondary electrons generated on each side of the foil are guided by the fields to the corresponding detector. Both the hitting position and the arrival time of the secondary electrons on corresponding detectors are measured in coincidence. A test with an ²⁴¹Am α source shows that the present monitor is capable of discriminating true events from heavy background radiations. A position resolution of 1.0 mm and a recording time resolution of 50 ns have been realized in the test.