Linac4 H⁻ ion sources

Area of Science:

• Particle Accelerators
• Plasma Physics
• Ion Sources

Background:

• The Large Hadron Collider (LHC) requires an upgraded injector chain for enhanced performance.
• Linac4, a 160 MeV linear accelerator, is a critical component of this upgrade.
• High-intensity negative hydrogen ion (H-) beams are essential for efficient LHC injection.

Purpose of the Study:

• To present the development and testing of a new H- ion source prototype for CERN's Linac4.
• To evaluate the performance of novel optics and beamline components designed to minimize emittance.
• To report on the initial testing of a Brookhaven National Laboratory-designed magnetron H- source at CERN.

Main Methods:

• Testing of a cesiated surface H- ion source prototype.
• Characterization of beam intensity, emittance, and electron-to-ion current ratio.
• Measurement of H- production efficiency in relation to RF power.
• Assembly and initial testing of a magnetron H- source at CERN.

Main Results:

• The H- ion source prototype achieved a beam intensity of 45 mA with an emittance of 0.3 π ⋅ mm ⋅ mrad.
• An optimal electron-to-ion current ratio below 1 was determined.
• A peak production efficiency of 1.1 mA/kW was reached.
• Initial tests of the magnetron H- source at a 0.8 Hz repetition rate were successful.

Conclusions:

• The developed H- ion source prototype meets the stringent requirements for the Linac4 upgrade.
• The new ion source optics and beamline components effectively minimize beam emittance.
• The successful integration and testing of the magnetron H- source demonstrate its potential for future applications.