Pink‐beam focusing with a one‐dimensional compound refractive lens |
| |
Authors: | Eric M Dufresne Robert W Dunford Elliot P Kanter Yuan Gao Seoksu Moon Donald A Walko Xusheng Zhang |
| |
Institution: | Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA |
| |
Abstract: | The performance of a cooled Be compound refractive lens (CRL) has been tested at the Advanced Photon Source (APS) to enable vertical focusing of the pink beam and permit the X‐ray beam to spatially overlap with an 80 µm‐high low‐density plasma that simulates astrophysical environments. Focusing the fundamental harmonics of an insertion device white beam increases the APS power density; here, a power density as high as 500 W mm?2 was calculated. A CRL is chromatic so it does not efficiently focus X‐rays whose energies are above the fundamental. Only the fundamental of the undulator focuses at the experiment. A two‐chopper system reduces the power density on the imaging system and lens by four orders of magnitude, enabling imaging of the focal plane without any X‐ray filter. A method to measure such high power density as well as the performance of the lens in focusing the pink beam is reported. |
| |
Keywords: | compound refractive lenses pink beam chromatic aberration |
|
|