P31 phosphor persistence at photopic mean luminance level

Area of Science:

• Visual perception research
• Optics and photonics

Background:

• P31 phosphor screens are widely used for visual experiments.
• Concerns exist regarding phosphor persistence affecting visual performance.
• Previous discussions focused on dot patterns; this study expands to gratings and luminance levels.

Purpose of the Study:

• To investigate the effects of pattern type (dots vs. gratings) and luminance (scotopic vs. photopic) on P31 phosphor persistence.
• To quantify P31 phosphor persistence under photopic conditions using precise measurements.
• To address the ongoing scientific debate on phosphor screen artifacts.

Main Methods:

• Physical measurements of P31 phosphor persistence were conducted.
• An extremely linear photometer with high temporal resolution was employed.
• Measurements focused on grating patterns at a mean luminance of 20 cd m⁻² (photopic range).

Main Results:

• Under photopic conditions with grating patterns, P31 phosphor persistence was measured.
• A rapid decay of residual grating contrast was observed.
• Contrast decayed to 1.4% of its original value within 50 ms after pattern offset.

Conclusions:

• P31 phosphor persistence exhibits rapid contrast decay under specific photopic conditions.
• The measured decay rate is a critical factor for designing experiments using P31 screens.
• While not problematic for all applications, this phosphor behavior requires careful consideration.