Design and commissioning of the RIKEN cryogenic electrostatic ring (RICE)

Area of Science:

• Physics
• Accelerator Science
• Cryogenics

Background:

• Electrostatic ion storage rings are crucial for various physics experiments.
• Achieving and maintaining cryogenic temperatures is essential for enhancing beam lifetime and stability.
• Previous electrostatic rings have limitations in achieving ultra-low temperatures and long beam storage times.

Purpose of the Study:

• To commission the RIKEN cryogenic electrostatic ring for ion beam storage under cryogenic conditions.
• To evaluate the performance of the ring regarding beam lifetime and vacuum quality at 4.2 K.
• To demonstrate the feasibility of using electrostatic components for guiding ion beams in a cryogenic environment.

Main Methods:

• Commissioning of a new electrostatic ion storage ring with a 15-keV ion beam.
• Utilizing a liquid-helium-free cooling system to achieve and maintain 4.2 K cryogenic conditions.
• Monitoring beam lifetime and identifying effects like longitudinal pulse compression using pick-up detectors.

Main Results:

• Successful commissioning of the RIKEN cryogenic electrostatic ring with a 15-keV Ne+ beam.
• Achieved a beam lifetime exceeding 10 minutes at 4.2 K, indicating a residual gas density of ~10^4 cm^-3.
• Observed and identified the effect of longitudinal pulse compression within the ring.

Conclusions:

• The RIKEN cryogenic electrostatic ring has been successfully commissioned, proving its capability for ion beam storage at cryogenic temperatures.
• The cryogenic operation significantly enhances beam lifetime, paving the way for advanced experiments requiring long storage times.
• The ring's design, utilizing electrostatic components and advanced cooling, represents a significant advancement in accelerator technology.