The use of BAS-TR imaging plates calibration in determining the resolving power of Fuji BAS-1800II image plate reader

• Published in: Journal of instrumentation 2018-01, Vol.13 (1), p.P01016-P01016
• Main Author: Alnaimi, R.
• Format: Article
• Language: English
• Subjects: Calibration; Image contrast; Mathematical analysis; Mylar; Neodymium lasers; Pixels; Plates; Resolution; Semiconductor lasers; Spatial resolution; Thickness; Video tapes; Wire cloth; X ray sources; YAG lasers
• ISSN: 1748-0221; 1748-0221
• DOI: 10.1088/1748-0221/13/01/P01016

The importance of this work lies in assuring the reliability of the results obtained from both imaging plates type BAS-TR and Fuji Image Reader BAS-1800II as they are widely used in calculating essential x-ray sources parameters such as the source size, x-ray flux and brilliance, hence, the calibration presented in this work. For such quantitative analysis, a common practice used by many researchers, where Gold resolution meshes are utilised for such purpose, however not quite successful due to the transmission effect of high energy photons at their edges as well as the pixeling effect while magnifying the scanned image to secure the edge spread function (ESF) data. In contrast, the use of resolution test target (RTT) and wire mesh grid together with a set of test samples i.e. Stanley blades, Ta, Ti and Si wafer of 100, 300, 15, and 490 micron thickness respectively appeared to be efficient in determining IP pixel size and the resolution of the reader. Two different experiments were conducted using two different targets and lasers of very different performance. The first, was a 15 μm VHS video tape composed of Mylar as carrier film with Fe2O3 and CrO2 powder. Nd:YAG laser of long pulse 800 ps, 50 Hz repetition rate and single shot were utilised. Whereas, the second experiment were conducted on a 9μm C wire and a short pulse 500fs Cerberus single shot laser was used. The results obtained from both experiments were pretty much similar. The imaging plate spatial resolution was measured to be: 3.4±0.2 pixels and a pixel size of 41.26±1.4 μm, whereas the smallest resolvable object visible to the reader (1:1 imaging with magnification factor) was of order 140.3±0.3 microns. This appeared to be worse by a factor of three which indicates the importance of the reader's calibration on a regular basis, and at the same time one has to reconsider any related work and calculation based upon the previous nominal values.