Optimizing the energy bandwidth for transmission full-field X-ray microscopy experiments.

Area of Science:

• X-ray microscopy
• Optics
• Materials science

Background:

• Full-field transmission X-ray microscopy (TXM) offers high-resolution imaging but faces limitations in acquisition speed due to optical efficiency.
• Increasing the energy bandwidth of X-ray sources, such as with multilayer monochromators, can enhance experimental flux.
• However, broader bandwidths can introduce chromatic aberrations, potentially degrading resolution.

Purpose of the Study:

• To theoretically and experimentally investigate the impact of increased energy bandwidth on the achievable resolution in TXM.
• To quantify the trade-off between enhanced flux and resolution when using multilayer monochromators compared to traditional methods.

Main Methods:

• Theoretical analysis of chromatic aberration effects on resolution with varying energy bandwidths.
• Experimental measurements of TXM resolution at different energy bandwidths (ΔE/E = 0.013%, 0.27%, 0.63%).
• Comparison of flux and resolution performance between multilayer monochromators and silicon double-crystal monochromators.

Main Results:

• Increased energy bandwidth leads to a trade-off between flux and resolution, primarily due to chromatic aberrations.
• Measurements confirmed that a limited effect on resolution is observed even with significant increases in energy bandwidth.
• A multilayer monochromator demonstrated an order of magnitude increase in flux compared to a silicon double-crystal monochromator.

Conclusions:

• Utilizing broader energy bandwidths, particularly with multilayer monochromators, is a viable strategy to significantly increase flux in TXM.
• The resolution degradation associated with wider bandwidths is manageable and does not negate the benefits of higher flux for many applications.
• This approach offers a pathway to faster, high-resolution X-ray imaging experiments.