Soft X-ray Reflectivity Beamline

Beamline overview

The soft x-ray energy region available from Indus-2 offers a great opportunity to pursue fundamental studies and carryout new technological developments. In the soft x-ray region x-ray reflectivity becomes very powerful tool to probe low contrast system such as carbonaceous soft condensed matter films as it enables one to enhance the contrast among low Z elements near the absorption edges of respective elements. A reflectometry facility has been setup at Indus-2 synchrotron source to pursue various pure and applied research programs

The Beamline
Inside view of monochromator
The Beamline
Inside view of monochromator

Beamline parameters & Optical layout

BEAMLINE PARAMETERS
Energy Range100-1500 eV
Flux109 1011 ph/sec
Resolving power1,000-5,000
Beam Size0.5 mm(H) Χ 0.3 mm (V)
MonochromatorVLS-PGM 3 gratings
Beamline parameters & Optical layout
  1. The soft x-ray reflectivity beamline uses a constant deviation angle variable line spacing plane grating monochromator with Hettrick type optics.
  2. The first optical element of the beamline is a horizontally deflecting and vertically mounted toroidal mirror, TM1, which accepts 2 mrad (H) and 3 mrad (V) of the emitted bending magnet radiation.
  3. TM1 focuses the light vertically on to the entrance slit S1, and horizontally on to the exit slit S2.
  4. The second mirror is a spherical mirror SM, which is vertically deflecting and forms a convergent beam on the plane grating.
  5. Three interchangeable gratings G1, G2 and G3 of line densities 1200, 400 and 150 lines/mm are used to efficiently cover the whole energy region of 100-1500 eV.

Experimental station

The experimental station consists of a two -axes high -vacuum compatible goniometer with x-y-z sample manipulation stages. The scattering geometry is in the vertical plane which is suitable for s-polarized reflectivity measurements as synchrotron light is plane polarized in the horizontal plane.

Experimental station
Sample Stage

The existing sample holder can accommodate a sample of size up to 300 mm length, 100 mm width and 50 mm height. The maximum weight of the sample in existing configuration can be about 5 Kg. Detector distance from the axis of rotation is 200 mm.

Experimental facility

1. Soft x-ray reflectivity:
Soft x-ray reflectivity
2. Soft x-ray Absorption:
Soft x-ray Absorption:
3. Soft x-ray Fluorescence:
Soft x-ray Fluorescence
Representative Soft x-ray fuorescence spectra of Cu, Al, GaAs
Soft x-ray Fluorescence

Application Areas

The experimental station of the beamline is a versatile instrument to measure soft x-ray reflectivity and absorption measurements which have a broad application areas in materials science

X-ray Optics

Characterization of reflectivity performance of soft x-ray reflective optics of upto 300 mm length.

Surfaces and interfaces characterizations

Angle dependent reflectivity technique is a powerful tool to analyse depth profile of thinfilm/ multilayer structures in a non-destructive manner.

Chemical and electronic properties

Soft x-ray fluorescence, Soft x-ray absorption and near edge soft x-ray reflectivity technique together provides details of chemical and electronic structure of thinfilm samples



1. Investigation of soft X-ray optical properties and their correlation with structural characteristics of zirconium oxide thin films.
Mangalika Sinha, Amol Singh, Raj kumar Gupta, A.K. Yada, Mohammed H. Modi
Thin Solid Films 2021
2. Carbon removal from a mirror-like gold surface by UV light, RF plasma, and IR laser exposure: a comparative study
P. K. Yadav, R. K. Gupta, A. K. Choubey, S. Ali, U. K. Goutam, and M. H. Modi
Applied Optics 60, 89-97 (2021) https://doi.org/10.1364/AO.400508>https://doi.org/10.1364/AO.400508
3. Interface modification of Cr/Ti multilayers with C barrier layer for enhanced reflectivity in the water window regime
P. Sarkar, A. Biswas, N. Abharana, S. Rai, M. H. Modi and D. Bhattacharyya
J. Synchrotron Rad.. 28, 224–230 (2021)
4. Ground calibration of Solar X-ray Monitor on board the Chandrayaan-2 orbiter
NPS Mithun, SV Vadawale, M Shanmugam, AR Patel, MK Tiwari, M.H. Modi et al
Experimental Astronomy 51 (1), 33-60 (2021)




1. Influence of spin orbit splitting and satellite transitions on nickel soft X-ray optical properties near its L2,3 absorption edge region
Kiranjot, M. H. Modi, R. K. Gupta, M. Sinha and P. K. Yadav
J. Synchrotron Rad. (2020). 27, 1633-1639 https://doi.org/10.1107/S1600577520011960
2. Solar X-Ray Monitor on Board the Chandrayaan-2 Orbiter: In-Flight Performance and Science Prospects
N.P.S. Mithun, Santosh V. Vadawale, Aveek Sarkar, M. Shanmugam, Arpit R. Patel, Biswajit Mondal, Bhuwan Joshi, P. Janardhan,Hiteshkumar L. Adalja, Shiv Kumar Goyal, Tinkal Ladiya, Neeraj Kumar Tiwari1, Nishant Singh, Sushil Kumar, Manoj K. Tiwari3,M.H. Modi, Anil Bhardwaj
Solar Physics 295, 139 (2020)
3. Effect of zirconium oxide local structure on soft X-ray optical properties near the oxygen K-edge region
M. Sinha, R.K. Gupta,  Kiranjot, Amol Singh, Mohammed H Modi
J. Appl. Phys 128, 065302 (2020)
4. Interface asymmetry in AlN/Ni and Ni/AlN interfaces: a study using resonant soft x-ray reflectivity
Kiranjot, R. Dhawan, R.K. Gupta, P. Yadav, Mohammed H Modi
Applied Surface Science, 529, 147199 (2020)
5. Interface evolution of Cr/Ti multilayer films during continuous to discontinuous transition of Cr layer"
P.Sarkar, A. Biswas, S. Rai, H. Srivastava, S. Mandal, M.H. Modi and D. Bhattacharyya
Vacuum 181, 109610 (2020)
6. "Interface evolution of Co/Ti multilayers with ultra-short period"
P.Sarkar, A. Biswas, S. Ghosh, S. Rai, M.H. Modi and D. Bhattacharyya
Thin Solid Films 693, 137688 (2020)
7. Interfacial Chemistry and Electronic Structure of Epitaxial Lattice-matched TiN/Al0.72Sc0.28N Metal/Semiconductor Superlattices Determined with Soft X-Ray Scattering
Bidesh Biswas, Sanjay Nayak, Vijay Bhatia, Ashalatha Indiradevi Kamalasanan Pilla, Magnus Garbrecht, M. H. Modi, Mukul Gupta and Bivas Saha
J. Vac. Sci. Tech. A 38, 053201 (2020)
8. Analysis of Au film surface after carbon layer removal with ultra violet radiation, RF plasma and IR laser
P. K. Yadav, R. K. Gupta, A. K. Choubey, Sabir Ali, and M. H. Modi
AIP Conference Proceedings 2265, 030253 (2020); https://doi.org/10.1063/5.0017399
9. Soft X-ray photon energy calibration using multilayer mirror
Kiranjot, Mangalika Sinha, R. K. Gupta, P. K. Yadav, and Mohammed H. Modi
AIP Conference Proceedings 2265, 030196 (2020); https://doi.org/10.1063/5.0017405




1. Continuous optical constants (δ & β) spectra of aluminium oxide near Al L and O K-edge region
M. Sinha, R.K. Gupta, P. Dasilva, P. Mercere, M.H. Modi
AIP Conference Proceedings 2115 (1), 030207 (2019)
2. A soft x-ray reflectivity beamline for 100-1500 eV energy range at Indus-2 synchrotron radiation source,
M.H. Modi, R.K. Gupta, S.R. Kane, V. Prasad, C. Kant, P.K. Yadav, V.K. Raghuwanshi., Singh Amol, Sinha M.
AIP Conf. Proc, 2054, 060022,Jan.2019.
https://doi.org/10.1063/1.5084653
3. Glancing angle soft x-ray reflectivity (SXR) and total electron yield (TEY) characterization of ZrO2 thin film near O K edge,
Mangalika Sinha, Amol Singh, R.K. Gupta R.K., M.H. Modi
AIP Conf. Proc, 2054, 040004,Jan.2019.
https://doi.org/10.1063/1.5084605
4. Interface Studies of Mo/Si Multilayers with Carbon Diffusion Barrier by Grazing Incidence EXAFS
N. Abharana, A. Biswas, P. Sarkar, P. Rajput, Rajnarayan De, K.D. Rao, M.H. Modi, D. Bhattacharyya, S.N. Jha and N.K. Sahoo
Thin solid films 673, 126-135 (2019)




1. Studies on thin films & multilayers using soft x-ray reflectivity beamlines at Indus synchrotron sources
M.H. Modi, R.K. Gupta, P.K. Yadav
Physics News, bulletin of the Indian physics association, Vol. 48, p. 70, 2018
2. Thermal and temporal stability of W∕B4C multilayer mirrors for space-based astronomical applications
Panini S. Singam, Maheswer Nayak, Rajkumar Gupta, Paresh C. Pradhan, Arindam Majhi, Shyama Narendranath, and Parameswaran Sreekumar
J. Astron. Telesc. Instrum. Syst. 4(4), 044003 (2018), doi: 10.1117/1.JATIS.4.4.044003
3. Optical performance of W/B C multilayer mirror in 4 the soft x-ray region
P. C. Pradhan, A. Majhi and M. Nayak,
J. Appl. Phys., 123, 095302 (2018)
4. Soft x-ray characterization of ion beam sputtered Magnesium oxide (MgO) thin film
Mangalika Sinha, Mukul Gupta, Philippe Jonnard, Mohammed H. Modi
Surf. Interface Anal.; 2018 DOI: 10.1002/sia. 6446



Science Highlights

Science Highlights

Science Highlights

Science Highlights

Team members

  1. Dr. M.H. Modi
  2. Dr. P. Yadav
  3. Shri R.K. Gupta
  4. Ms Shruti Gupta
  5. Shri Pushkardeep
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