William B. Herrmannsfeldt

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This paper describes the computer studies of the electromagnetic and mechanical properties of an S-band superconducting accelerator. The structure under discussion is intended for a test accelerator using a 15-cavity niobium traveling-wave resonant-ring structure operating in the 28/3 mode. Many of the parameters for this short test accelerator, such as the(More)
A system of large rectangular Fresnel lenses has been used in the laser alignment system for the SLAC two-mile accelerator. The alignment system consists of a He-Ne laser light source, a photoelectric detector, and the lenses, one of which is located at each of 297 points which are to be aligned. Each lens has the proper focal length to focus the laser to a(More)
A lasertron (a microwave “triode” with an RF output cavity and an RF modulated laser to illuminate a photocathode) is a possible high power RF amplifier for TeV linear colliders. As the first step toward building a 35 MW, S-band lasertronfor a proof of principle demonstration, a 400 kV dc diode is _m being d-esigifed with aAGa& photocathode, a drift-tube(More)
The first observation of beam break-up at SLAC was made on April 27, 1966, one week after the beam was first turned on over two-thirds of the accelerator’s two-mile length. I The event caused more astonishment than panic because the observed beam break-up current threshold of 10 to 20 mA peak, while much lower than in other shorter accelerators, was not far(More)
Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron-positron colliders, compact accelerators, and FEL sources. We have attained 200MW peak power ‘at 11.4 GHz from a relativistic klystron, and 140MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We(More)
-Heavy ion accelerators are the most recent entrants in the effort to identify a practical driver for inertial confinement fusion. They . are of interest because of the expected efficient coupling of ion kinetic energy to the thermal energy needed to implode the pellet and because of the good electrical efficiency of high intensity particle accelerators.(More)
An X band klystron using a sheet beam and wiggler focusing was simulated using the 2 + t dimensional particle in cell code MASK.’ Simulation of the rf cavities was by means of the port approximation used in modell ing of standard klystrons.2 The wigglers, which would need permanent magnets to achieve the required field strengths, were modelled using an(More)
Future linear colliders have a need for high power, high frequency, and short-pulse radio frequency sources. The proposed “cluster klystron” should give over 1 GW of 12 GHz radio frequency power, can employ direct current or a long high-voltage pulse, but can be gated to give pulses down to a few tens of nanoseconds. The device consists of 42 parallel 100 A(More)