Operating a triple stack microchannel plate-phosphor assembly for single particle counting in the 12-300 K...

Area of Science:

• Physics
• Instrumentation
• Physical Chemistry

Background:

• Microchannel plate (MCP) detectors are crucial for particle detection.
• Understanding detector performance at cryogenic temperatures is vital for advanced scientific applications.

Purpose of the Study:

• To evaluate the operational performance of a microchannel plate (MCP) and phosphor screen anode assembly across a wide temperature range (300 K to 12 K).
• To assess the suitability of this detector for position-sensitive particle counting at cryogenic temperatures and high event rates.

Main Methods:

• Tested an MCP-phosphor screen anode assembly from 300 K down to 12 K.
• Measurements included dark counts (15 Hz) and alpha source detection (6.4 kHz).
• Monitored MCP bias current, phosphor decay time using a photomultiplier tube (PMT), and pulse height distribution.

Main Results:

• MCP bias current decreased by a factor of 2.1 x 10^3 from 300 K to 12 K.
• Phosphor decay time varied non-monotonically with temperature, from 12 µs at 300 K to 5 µs at 12 K.
• Typical pulse height spectra were observed at 300 K and 12 K, with degradation at intermediate temperatures.

Conclusions:

• The MCP-phosphor detector assembly is suitable for position-sensitive particle counting down to 12 K, even at rates exceeding 6 kHz.
• This performance is critical for developing new instrumentation for advanced research, such as studying complex molecular ion interactions.