U. Feldman, EBIT measurements that can help establish the excitation conditions in hotsolar upper atmosphere plasmas, PHYS SCR, 63(4), 2001, pp. 276-283
In principle, the temperatures of solar upper atmosphere plasmas can be der
ived from the degree of ionization of the ions in the plasma and also from
intensity ratios of properly selected lines within particular ions. When su
ch comparisons are made, more often than not discrepancies between the two
methods appear. The reason for the discrepancies may be due to wrong assump
tions regarding the atomic processes that occur in the emitting plasma or t
o inaccuracies in the atomic cross-sections used in deriving the temperatur
e sensitive line intensity ratios. This paper presents several types of spe
ctral lines for which their intensity ratios are expected to be sensitive t
o the temperature of solar plasmas. However, before the diagnostic capabili
ties of these lines can be explored, the dependency of intensity ratios on
temperature needs to be established from a well-understood laboratory measu
rement. It is proposed that attempts be made to measure some of the listed
intensity ratios as a function of electron beam energy in an Electron Beam
Ion Trap (EBIT) machine.