Electron string ion sources for carbon ion cancer therapy accelerators.

Area of Science:

• Nuclear Physics
• Medical Physics
• Accelerator Technology

Background:

• Electron String Ion Sources (ESIS) are evaluated for producing pulsed carbon ion beams.
• Cancer therapy accelerators require high-intensity ion beams for effective treatment.
• Existing ion sources may have limitations in producing specific ion species and intensities.

Purpose of the Study:

• To assess the suitability of Electron String Ion Sources (ESIS) for generating pulsed C(4+) and C(6+) ion beams for cancer therapy.
• To evaluate the performance of the Krion-6T ESIS for producing high-intensity carbon ion beams.
• To investigate the potential of ESIS for producing radioactive (11)C ion beams for PET-guided therapy.

Main Methods:

• Experimental testing of the Krion-6T Electron String Ion Source.
• Measurement of ion beam intensity (ions per pulse and ions per second).
• Testing of a specialized cryogenic cell for pulse injection of gaseous species into the electron string using the Krion-2M ESIS.

Main Results:

• The Krion-6T ESIS produces >10^10 C(4+) ions/pulse and ~5x10^9 C(6+) ions/pulse.
• Krion-6T achieves >10^11 C(6+) ions/second at 100 Hz, with potential for higher repetition rates.
• Conversion efficiency of methane to C(4+) ions reached 5%-10% in experiments with stable methane.

Conclusions:

• ESIS, particularly the Krion-6T, is suitable for producing pulsed C(4+) and C(6+) beams for cancer therapy accelerators like synchrotrons and cyclotrons.
• ESIS technology shows promise for generating radioactive (11)C ion beams for advanced cancer therapy applications.
• The demonstrated conversion efficiency is considered sufficient for producing (11)C(4+) beams from radioactive methane for synchrotron injection.