A 2.8 K cryogen-free cryostat with compact optical geometry for multiple photon counting.

Area of Science:

• Particle Physics
• Materials Science
• Cryogenics

Background:

• Growing interest in solid scintillators for low-temperature particle physics experiments.
• Need for efficient photon detection at cryogenic temperatures (below liquid helium).
• Existing techniques face limitations in photon collection efficiency and sample size.

Purpose of the Study:

• To describe a novel closed-cycle optical cryostat for low-temperature solid scintillator studies.
• To enhance photon collection efficiency for multiple photon counting techniques.
• To facilitate the study of scintillators under gamma irradiation at cryogenic temperatures.

Main Methods:

• Development of a closed-cycle optical cryostat with a base temperature of 2.8 K.
• Implementation of a compact optical geometry with a large numerical aperture (approx. 0.79).
• Utilizing a setup capable of handling relatively large scintillator sample sizes.

Main Results:

• Achieved a base temperature of 2.8 K, suitable for liquid helium temperature studies.
• The cryostat's optical geometry provides 40% solid angle coverage for photon collection.
• Demonstrated significant gain in photon collection efficiency compared to conventional methods.

Conclusions:

• The developed optical cryostat is a valuable asset for low-temperature multiple photon counting.
• Enhanced photon collection efficiency facilitates detailed studies of scintillators under gamma irradiation.
• The system supports advancements in particle physics research requiring sensitive cryogenic detectors.