X-ray imaging using amorphous selenium: determination of x-ray sensitivity by pulse height spectroscopy

Area of Science:

• Materials Science
• Medical Physics
• Imaging Technology

Background:

• Amorphous selenium (a-Se) is gaining traction for advanced x-ray imaging applications.
• Existing methods for evaluating a-Se x-ray sensitivity are indirect, measuring surface potential changes.
• These indirect methods combine W+/- measurements with factors like absorbed energy and layer capacitance, introducing potential errors.

Purpose of the Study:

• To develop a direct and more accurate method for evaluating W+/-, the energy required to generate an electron-hole pair in a-Se.
• To overcome the limitations and inaccuracies inherent in previous indirect measurement techniques.

Main Methods:

• Developed a direct evaluation method for W+/- in a-Se.
• Utilized pulse height spectra derived from the absorption of individual monoenergetic x-ray photons.
• Analyzed the energy absorption events at the fundamental level of single photon interactions.

Main Results:

• Successfully developed a direct method for evaluating W+/- in amorphous selenium.
• The new method provides a more precise measurement of the energy absorption required for electron-hole pair generation.
• This direct approach minimizes errors associated with indirect surface potential measurements.

Conclusions:

• The newly developed direct method offers a significant improvement for characterizing the x-ray sensitivity of amorphous selenium.
• Accurate W+/- determination is crucial for optimizing a-Se performance in next-generation x-ray imaging systems.
• This advancement facilitates more reliable development and application of a-Se photoconductors in medical imaging.