Development of a higher power cooling system for lithium targets

Area of Science:

• Medical physics
• Accelerator technology
• Nuclear engineering

Background:

• The University of Birmingham utilizes an accelerator-based Boron Neutron Capture Therapy (BNCT) beam.
• The system employs a solid thick lithium target cooled by heavy water.
• Planned upgrades to the Dynamitron accelerator will increase beam current to at least 3 mA.

Purpose of the Study:

• To investigate upgrades for the target cooling system to manage increased power from the Dynamitron accelerator.
• To evaluate the effectiveness of a phase change coolant, "binary ice", compared to traditional chilled water.

Main Methods:

• Experimental testing of a submerged jet cooling system.
• Utilizing an induction heater to simulate the power input from the Dynamitron beam.
• Measuring heat input to target temperature relationships and cooling circuit pumping rates.

Main Results:

• Binary ice demonstrated no significant improvement over chilled water in the submerged jet system.
• Both cooling methods exhibited similar heat input to target temperature relationships for a given flow rate.
• The relationship between cooling circuit pumping rate and target temperature was analyzed.

Conclusions:

• Current cooling system designs are adequate for the planned accelerator upgrades.
• Further investigation into alternative cooling methods may be necessary if performance requirements change.
• The study provides essential data for optimizing BNCT beam operations.