Determination of the energy or pressure of a solar X-ray structure using X-ray filtergrams from a single filter

While the X-ray fluxes measured through two different broadband filters can be used to derive the temperatures and emission measures of solar plasmas, it is generally assumed that no plasma parameters can be measured quantitatively with a single filtergram alone. We show that the thermal energy density (or pressure) of a solar plasma can be measured with an ideal single filtergram. Calculations have been done to compare the properties of the Skylab S-054 X-ray telescope filters to those of the ideal filter.