Science | Kawal Sawhney

Kawal Sawhney
Test Beamline

Kawal Sawhney Kawal Sawhney is the principal beamline scientist for the Test beamline B16. He is also the head of the optics and metrology group at Diamond. The Test beamline is being developed for testing of optics and detectors, and for the development of novel experiments and techniques. Prior to joining Diamond, Kawal was the head of the Beamlines Section at the Indian synchrotron facilities Indus-1 and Indus-2, where he designed and constructed several beamlines. His main interests are in designing beamline optics and carrying out research in the field of x-ray optics.

Email: Kawal Sawhney
Tel: +44 (0) 1235 778169
Beamline B16 - Test Beamline

Key Research Areas

Beamline optics, especially nano-focusing optics. Development of beamline instrumentation, novel optical schemes for beamlines, multilayer optics, soft x-ray polarimetry, metrology.

Current Research Interests

Optics for synchrotron radiation is continuously evolving with efforts by research facilities and industry to match the requirements of the third-generation low-emittance synchrotron sources and to reach diffraction limited performance. To achieve this goal, optics development and its metrology have to go hand-in-hand. We are pursuing both these activities.

X-ray focusing is a fast evolving field and significant developments have taken place in the last few years. Complementary technologies are being applied based on reflection, refraction and diffraction to achieve smaller and smaller focused beams. In collaboration with Lucia Alianelli from the Diamond Optics Group and Bob Stevens from the CLRC Central Microstructure Facility (CMF), planar x-ray kinoform lenses in silicon and other materials are being developed which will be able to focus the synchrotron beam to sub-micron sizes at the sample position. The Test beamline will be a very valuable tool to undertake such developments in optics.

Polarisation characterisation of radiation emitted from helically polarising undulators like APPLE – II is an essential input for doing precise MCD type of experiments. DLS is collaborating with SRS to develop a UHV compatible polarimeter to work in the soft x-ray regime. This multilayer-based polarimeter will aid in measuring the complete polarisation state of the SR beam and will be a useful diagnostics tool for soft x-ray beamlines on Diamond like I06 Nanoscience.

A Slope Measuring Profilometer is being also developed which would be able to measure the figure error of x-ray beamline optics to sub-microradian resolution. This instrument will aid the characterisation and calibration of future Diamond beamlines.

Selected Publications

  1. A novel undulator-based PGM beamline for circularly polarised synchrotron radiation at BESSY IIK J S Sawhney, F Senf, M Scheer, F Shäfers, J Bahrdt, A Gaupp and W Gudat, Nucl. Instrum. & Meths., A390, 395-402 (1997)
  2. Characterization of molybdenum/silicon X-ray multilayers, M. Nayak, M H Modi, G S Lodha, A K Shrivastava, P Tripathi, A K Sinha, K J S Sawhney and RV Nandedkar, Nucl. Instrum. & Meths., B199, 128-132 (2003)
  3. A simple and precise TXRF spectrometer: construction and its applications, M K Tiwari, K J S Sawhney, B Gowri Sankar, V K Raghuvanshi and R V Nandedkar, Spectrochimica Acta Part B, 59, 1141-1147 (2004)
  4. PGM beamline with constant energy resolution mode for U49-2 undulator at BESSY-II, K J S Sawhney, F Senf and W Gudat, Nucl. Instrum. & Meths.,A467, 466-469 (2001)
  5. X-ray Optics for beamlines at Diamond Light Source, S Alcock, L Alianelli and K J S Sawhney, Proc. SPIE - 6317, 63170C0-C9 (2006)
  6. Ray-tracing simulation of parabolic compound refractive lenses, L Alianelli, M Sanchez del Rio and K J S Sawhney, Spectrochimica Acta B, (accepted) (2007)
  7. Diamond Beamline I24: A Flexible Instrument for Macromolecular Micro-crystallography, G Evans, L Alianelli, M Burt, A Wagner and K J S Sawhney, AIP Conference Proceedings 879 -Ninth International Conference on Synchrotron Radiation Instrumentation, Korea, 836-839 (2007)