Electron temperature measurements with heavy ion beam probes

The total abundance of secondary ion current detected from a heavy ion beam probe (proportional to n σeff ) is a function of the electron temperature through the collision cross section. n and T e can be separated by probing the same volume with two different ion species or monitoring two different charge states produced from the same ion. Measurements at Rensselaer (RENTOR) have demonstrated the technique by using a single detector system to look at Cs+ + and Cs+ + + on successive plasma shots. Data from EBT‐S has shown a sensitivity to electron energies up to 1 MeV, but accurate determination of bulk temperatures is limited to a few hundred volts. Two new analyzers have been installed on RENTOR to demonstrate the capability of providing T e profiles during a single shot. Calibration of these measurements requires a detailed accounting of all input beam ions, reaction products, and sample volumes.