Demonstration of the superconducting electron accelerator as a high-intensity high-resolution device

Abstract

In recent experiments with the superconducting injector system, beam intensity and beam quality objectives for the superconducting electron accelerator have been achieved and exceeded. At 8.5 MeV and 25 μA, spreads in phase and energy of 1.2° and 9.2 keV fullwidth at half-maximum, respectively, have been measured, and at 250 μA the spreads in the phase and energy increased by only 10%.

Microwave Superconductivity

“…In particular the Mattis-Bardeen theory [27] of superconductor electrodynamics demonstrated the importance of the superconducting energy gap and quantum coherence effects in the complex conductivity and surface impedance of superconductors. Mattis-Bardeen theory predicts that losses in fully-gapped superconductors will become arbitrarily small as the temperature is decreased, enabling ultra-high quality factor superconducting resonators for highefficiency particle accelerators, as initially demonstrated by Schwettman and Turneaure utilizing a solid Nb cavity [95]. Materials and infrastructure development over many years has made solid Nb cavities the method of choice for highefficiency and compact charged particle accelerators, [3] even to the point that normal metal accelerator cavities are now being replaced by their superconducting versions [96].…”

Microwave Superconductivity

“…In particular the Mattis-Bardeen theory [26] of superconductor electrodynamics demonstrated the importance of the superconducting energy gap and quantum coherence effects in the complex conductivity and surface impedance of superconductors. Mattis-Bardeen theory predicts that losses in fully-gapped superconductors will become arbitrarily small as the temperature is decreased, enabling ultra-high quality factor superconducting resonators for high-efficiency particle accelerators, as initially demonstrated by Schwettman and Turneaure utilizing a solid Nb cavity [90]. Materials and infrastructure development over many years has made solid Nb cavities the method of choice for high-efficiency and compact charged particle accelerators, [3] even to the point that normal metal accelerator cavities are now being replaced by their superconducting versions [91].…”

Invention of the Free Electron Laser

“…The project was begun in the fall of 1972 using the very high quality, high duty cycle electron beam from Stanford's new 50 MeV superconducting accelerator [27] and concluded in 1977 with the publication of an article in Physical Review Letters describing the first successful operation of a 3-micron FEL oscillator. Project staff included research scientists Luis Elias and Todd Smith, and graduate student Dave Deacon, assisted by the faculty and professional staff of the W. W. Hansen High Energy Physics Laboratory (HEPL).…”