Commissioning and first result of undulator based atomic, molecular, and optical sciences (AMOS) beamline at Indus-2 synchrotron radiation source.

This article focuses on the commissioning and initial performance results of the Atomic, Molecular, and Optical Sciences (AMOS) beamline at the BL-5 undulator port of the 2.5 GeV Indus-2 synchrotron facility in Indore, India. The beamline employs a varied line spacing plane grating monochromator (VLSPGM) with four gratings covering an energy range of 6–800 eV, enabling high-resolution vacuum ultraviolet (VUV) and soft x-ray spectroscopy for gas-phase and solid-state samples. Commissioning tests demonstrated a photon flux of approximately 10¹² photons/s and a resolving power near 7,740 (close to the design value of 10,000), validated through photoabsorption spectra of xenon and oxygen gases and soft x-ray absorption spectroscopy (XAS) of standard solid samples. The beamline’s design, including a differential pumping system for windowless operation and precise control systems, positions it as a versatile tool for advanced studies in atomic, molecular, and condensed matter physics, comparable in capability to similar international facilities.