Long-pulse diagnostic calorimeter for the negative ion source testbed BATMAN upgrade

Area of Science:

• Plasma Physics
• Fusion Energy Engineering
• Accelerator Technology

Background:

• The RF-driven negative ion source testbed BATMAN upgrade is crucial for developing neutral beam injection systems for ITER and DEMO.
• Previous limitations in pulse length were due to titanium sublimation pumps and an inertially cooled calorimeter.

Purpose of the Study:

• To enhance the BATMAN upgrade for steady-state operation and advanced beam optics studies.
• To develop and implement a long-pulse compatible, actively cooled diagnostic calorimeter.

Main Methods:

• Designed and manufactured a new actively cooled diagnostic calorimeter with embedded cooling channels.
• Utilized a 2D profile of beam power density with 20 mm spatial resolution.
• Employed infrared thermography and thermocouples for power density evaluation.

Main Results:

• The new calorimeter allows for steady-state operation, overcoming previous pulse length limitations.
• It provides a 2D power density profile with 20 mm resolution.
• Active cooling manages 160 kW beam power at 45 kV acceleration.

Conclusions:

• The upgraded BATMAN testbed facilitates long-pulse operation essential for fusion energy research.
• The actively cooled calorimeter significantly enhances diagnostic capabilities for neutral beam injection systems.
• This development supports the advancement of ITER and DEMO projects.