Significant progress has been made by the CLIC collaboration to understand the phenomena which limit gradient in normal-conducting accelerating structures and to increase achievable gradient in excess of 100 MV/m. Scientific and technological highlights from the CLIC high-gradient program are presented along with on-going developments and future plans. I will also give an overview of the range...
Laser Plasma Accelerators (LPA) rely on the control of the electrons motion with intense laser pulses [1]. Improvements of electron beam parameters such as divergence, energy or energy spread are possible thanks to this fine optical control. This manipulation of electrons with intense laser pulses allows a fine mapping of the longitudinal and radial components of giant electric fields that can...
We will present overview of plasma modeling and experiments related to vacuum arc devices. The character of the plasma flow depending on the anode geometries relatively to the expanding plasma jet will be analyzed. Specifics of the high-current vacuum arc will be examined including several effects associated with high-current arc behavior in a magnetic field and transition from diffusion to...
The Plasma Window is a novel apparatus that utilizes a stabilized plasma arc as interface between vacuum and atmosphere or pressurized targets without solid material. Additionally, the plasma has a lensing effect on charged particles. Furthermore, plasma from a plasma window was extended over 2 cm into atmosphere to form a plasma shield (Plasma Shield is basically a Plasma Window extended to...
A new type of micropropulsion device is presented – the inline-screw-feeding vacuum-arc thruster (ISF-VAT). This thruster couples a conventional ”triggerless” vacuum arc ignition system with a feeding mechanism that maintains a steady state discharge performance. The feeding mechanism implements a screw action on a central cathode rod. At a predetermined rate, a complete and uniform erosion of...
RF breakdown has a negative impact on a RF cavity’s performance, especially with the presence of strong magnetic fields. This issue can arise in designs of muon ionization cooling channel, RF guns, klystrons and in many other applications. The MuCool Test Area at Fermilab is the facility that allows us to study the effects of static magnetic field on RF cavity operation. As a part of this...
The study of surface flashover behavior in nanoscale dielectrics has broad application in nano- and microfabricated on-chip electronics such as energy converters, logic/memory, mass spectrometers, field emission devices, and compact accelerators. Most microscale devices incorporate planar dielectric architectures (e.g. gate oxides in transistors) without exposed surfaces. Therefore, relatively...
A novel coaxial resonator to investigate two-surface multipactor discharges on metal and dielectric surfaces in the gap region under vacuum conditions (~10-8 mbar) has been developed and tested. The resonator is ~ 100 mm in length with an outer diameter of ~ 60 mm (internal dimensions). A pulsed RF source delivers up to 30 W average power over a wide frequency range 650-900 MHz to the RF...
