(After Ref. 28 ) Fast images of the visible emission during (a) the snowplow mode, and (b) the gas-puff mode of operation in the Stanford coaxial plasma accelerator. Image exposure time = 100 ns, Applied potential= 4 kV, Capacitance = 112 μF.
Schematic of the Thomson-type mass and energy spectrometer.
Magnetic field measurements used for Geant4 simulations.
Electric field calculations used for Geant4 simulations. Contours represent electric potential and vectors represent electric field. The magnet structure, detector, and top and bottom boundaries of the calculation region were assumed to be at the reference (ground) condition.
Example Geant4 simulations for protons of different energies. Ion trajectories are represented by blue curved lines.
Image of measured proton Thomson parabola with overlying Geant4 calibration. Incorporating accurate non-uniform magnetic and electric fields improves species identification and calibration accuracy.
Image processing to extract Thomson parabolas: (a) original image, (b) conversion to binary image for least-squares fit to Thomson parabola, (c) superimposed fit onto mean-filtered original image, (d) extracted intensity (arbitrary units) along fit parabola.
Proton energy spectrum for single accelerator pulse. 4 kV applied voltage, 900 J capacitor bank energy. Uncertainty bars are shown for select points of the spectrum.
Left panel: MCP detector image of measured Thomson parabolas with Geant4 calibration overlaid for anaccelerator pulse which exhibited contaminant species in the beam. Right panel: Energy spectra for contaminant species, assuming they are various charge states of iron.
Article metrics loading...
Full text loading...