Effect of gas pressure on energy resolution of a soft X-ray beamline

Ionization chamber is often used to calibrate photon energy of the monochromator and evaluate quantitatively the energy resolving power by measuring photoabsorption or photoionization spectra of various gases.However,the effect of gas collision broadening is usually ignored in conventional method,which results in lower energy resolution than the true value.In this paper,the effect of gas pressure is discussed and an analytical method with gas pressure correction is proposed.It can effectively eliminate the effect of gas collision broadening.