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A beamline to carry out photoabsorption and fluorescence experiments using INDUS-1 synchrotron radiation source has been recently commissioned at the Centre for Advanced Technology, Indore India. The optical system for the beamline consists of a pre-focusing toroidal mirror, an indigenously developed one meter Seya-Namioka monochromator and a post-focusing toroidal mirror to cover the wavelength range of 500A–2000A. An experimental chamber for performing VUV excited fluorescence on solid samples is coupled to the beamline. A quarter meter gas cell has also been fitted with the experimental station. In this paper, we have presented the salient features of the beamline and the recorded photoabsorption spectra of benzene and benzene-d6.

In this paper we have discussed the optical design principle and imaging characteristics of the angle resolved photoelectron spectroscopy (ARPES) beamline which have been recently commissioned at the Indus-1 synchrotron radiation source, Centre for Advanced Technology (CAT), Indore. The heart of the beamline is the 1.4 meter focal length Toroidal Grating Monochromator (TGM-1400) supplied by M/S. Jobin-Yvon, France. The monochromator uses three interchangeable aberration corrected toroidal holographic gratings having groove densities of 1800g/mm, 600g/mm and 200g/mm and it covers the spectral region of 40 A to 1000A with an average spectral resolution of 0.4A. A toroidal mirror focuses the light originating from the tangent point of the synchrotron source onto the entrance slit of the monochromator and a second toroidal mirror focuses the light emerging from the exit slit of the monochromator at the experimental sample position. All the three optical components are coated with platinum. After optimising the geometrical parameters of the beamline, extensive ray tracing work has been performed to evaluate the imaging properties of the beamline.

The Photophysics beamline at INDUS-1 synchrotron source will be used for carlying out various types of experiments in atomic, molecular and condensed matter physics. In this beamline a toroidal mirror focuses the light originating from the tangent point of the synchrotron source onto the horizontal entrance slit of a one meter Seya-Namioka inonochromator. The dispersed light emerging from the exit slit of the monochromator is focused by a second toroidal mirror at the sample under study. We have extensively used the software package “SHADOW” for raytracing work and plotted the spot diagrams at the entrance slit, exit slit and the sample position. For ray tracing purpose we have first used the optimised layout of the beamline. In order to accommodate off-the-shelf optical components, the optical layout was modified by changing the distance between the second toroidal mirror and the sample position. We have plotted the spot diagram at the sample position for various distances between the second toroidal mirror and the sample position. Finally, we have established the most suitable value of the second toroidal mirror to the sample position distance for which the spot size at the sample position is minimum.

A 450 Mev synchrotron radiation source INDUS-1 is being constructed at the Centre for Advanced Technology, Indore, as a national facility for performing various types of experimental work in the vacuum ultra violet to soft X-ray region of the spectrum. In this facility a high resolution VUV beamline will be set up for various types of atomic and molecular physics experiments/This beamline uses a combination of three cylindrical mirrors which focuses the light originating from the tangent point of the storage ring onto the horizontal entrance slit of a spectrometer. The spectrometer uses a 66.65 meter concave grating having a groove density of 4800 g/mm which is mounted in the off-plane eagle mounting. It will cover the spectral region of 400 A - 2000 A with an average spectral resolution of 0.005 A. In this paper we have discussed the intensity and the imaging properties of the beamline.