Chemical method to increase extreme ultraviolet microchannel-plate quantum efficiency. II. Analysis and optimization

Area of Science:

• Physics
• Materials Science
• Chemistry

Background:

• Microchannel plate (MCP) detectors are crucial for detecting ultraviolet (UV) radiation.
• Improving the quantum detection efficiency (QDE) of MCP detectors is essential for advanced scientific applications.
• Current MCP detector efficiencies require enhancement, particularly in the extreme ultraviolet (EUV) spectrum.

Purpose of the Study:

• To investigate a wet chemical method for enhancing the EUV QDE of MCP detectors.
• To understand the physical and chemical mechanisms responsible for QDE improvement.
• To optimize the chemical process for maximum QDE enhancement.

Main Methods:

• Utilized a wet chemical method involving ion exchange on MCP input surfaces.
• Tested nitric acid, acetic acid, and water as active reactants.
• Analyzed changes in surface roughness, surface density, and secondary electron emission coefficient.
• Measured MCP QDE across the 1216-304 Å wavelength range.

Main Results:

• Achieved a 2.6-4.4 fold increase in MCP QDE for the tested wavelengths.
• Demonstrated an absolute QDE of approximately 50% at 304 Å.
• Observed that ion exchange increases the secondary electron emission coefficient.
• Physical changes include increased surface roughness and decreased surface density.

Conclusions:

• The wet chemical ion-exchange method effectively enhances EUV QDE in MCP detectors.
• The enhancement is attributed to increased secondary electron emission, surface roughness, and decreased surface density.
• This technique offers a viable pathway to significantly improve UV detector performance.