User:Alexander.Opolka

Alexander Opolka

Alexander Opolka

Department: F&E3-XOM

Field of work: X-ray lenses

Building: 307

Room: 339

Phone: 0721-608-22786

E-mail: alexander.opolka@kit.edu

Job Description

Developing multi-focus compound refractive X-ray lenses

The field of view of X-ray microscopes based on a single compound refractive lens (CRL) is limited to a few hundred micrometers. This is due to the high ratio of lens length to lens aperture (approx. 100). One way to increase the field of view would be to arrange multiple CRLs in a lens array. However, to date, no multi-focus CRL arrays have been developed in which every lens is directed at the same point in the sample plane at the optical axis.

Multi-focus CRLs for X-rays might prove useful in two fields. One is full-field X-ray microscopy with X-ray tubes, where several pictures of a sample could be taken from slightly different angles. In this way, the relatively long exposure time (currently on the order of hours) could be reduced dramatically (in the case of a 5 x 5 lens array, to minutes). This would result in practicable exposure times for full-field X-ray microscopy in materials science laboratories. A second possible application for multi-focus CRLs would be in computer-assisted tomography (CAT) at synchrotron sources. Because high-resolution CAT images require pictures from many different angles, reducing the number of sample rotations needed would be a clear advantage. By combining a multi-focus CRL with a suitable condenser, pictures could be taken simultaneously from different angles before rotating the sample, thus considerably reducing the total exposure time. Ultimately, multi-focus CRLs could also benefit the X-ray microscope setup MiQA at the KIT synchrotron (Image beamline) by broadening its scope of application and reducing costs.

Expertise

Devices

• Optical microscope
• SEM
• Hot-plates
• Vacuum Oven
• MiQA

Processes

• LIGA exposure
• PEB
• Development

Software

• MATLAB
• Origin
• Zemax
• Solid Edge