Ampere-class Bright Field Emission Cathode Operated at 100 MV/m
arXiv:2102.00071 · doi:10.1103/PhysRevAccelBeams.24.123401
Abstract
High current bright sources are needed to power the next generation of compact rf and microwave systems. A major requirement is that such a source could be sustainably operated at high frequencies, well above 1 GHz, and high gradients, well above 100 MV/m. Field emission sources offer simplicity and scalability in a high frequency era of the injector design, but the output rf cycle charge and high gradient operation remain a great and largely unaddressed challenge. Here, a field emission cathode based on ultra-nano-crystalline diamond or UNCD, an efficient planar field emission material, was tested at 100 MV/m in an L-band injector. A very high charge of 38 pC per rf cycle (300 nC per rf pulse corresponding to rf pulse current of 120 mA) was demonstrated. This operating condition revealed a space charge dominated emission from the cathode and revealed a condition under which the 1D Child Langmuir limit was surpassed. Finally, a beam brightness of A/mrad was estimated.
References in corpus (15)
- Compression of sub-relativistic space-charge-dominated electron bunches for single-shot femtosecond electron diffraction
- Thermal runaway of metal nano-tips during intense electron emission
- Electron Emission Area Depends on Electric Field and Unveils Field Emission Properties in Nanodiamond Films
- In situ Observation of Dark Current Emission in a High Gradient RF Photocathode Gun
- Field emission microscopy of carbon nanotube fibers: evaluating and interpreting spatial emission
- Ballistic Bunching of Photo-Injected Electron Bunches with Dielectric-Lined Waveguide
- Theoretical Evaluation of Electronic Density-of-states and Transport Effects on Field Emission from -type Ultrananocrystalline Diamond Films
- Experimental demonstration of the correction of coupled transverse dynamics aberration in an rf photoinjector
- Mean Transverse Energy of Ultrananocrystalline Diamond Photocathode
- Field Electron Emission Induced Glow Discharge in Nanodiamond Vacuum Diode
- Demonstration of Planar Ultrananocrystalline Diamond Field Emission Source Operating in SRF Injector at 2 Kelvin
- Topological Cathodes: Controlling the Space Charge Limit of Electron Emission Using Metamaterials
- Fast Pattern Recognition for Electron Emission Micrograph Analysis
- FEbeam: Cavity and Electron Emission Data Conversion, Processing and Analysis. A Freeware Toolkit for RF Injectors
- Evidence for Anti-Dowell-Schmerge Process in Photoemission from Diamond