Measurement of photoionization yield in low-density barium photoplasma study

A finite-sized barium (Ba) photoplasma is generated through a two-step resonant photoionization method by shining laser pulses onto an atomic beam of Ba. The photoionization yield is estimated from the ratio of photoion density to neutral atom density measured in the laser-atom interaction region. The neutral atom density in the atomic beam is measured by an optical absorption technique where a Ba hollow cathode lamp (Ba-HCL) is used as an emission source. Since the photoplasma has a finite volume and it is pulsed in nature, the photoion density in the photoplasma is estimated through the collection of charge from the photoplasma. The measured ionization yield is compared with the calculated value that is obtained from an in-house developed code. It is observed that the values are in good agreement.