Record high-gradient SRF beam acceleration at Fermilab

Abstract

Many modern and future particle accelerators employ high gradient superconducting RF (SRF) to generate beams of high energy, high intensity and high brightness for research in high energy and nuclear physics, basic energy sciences, etc. In this paper we report the record performance large-scale SRF system with average beam accelerating gradient matching the International Linear Collider (ILC) specification of 31.5 MV m −1 . Design of the eight cavity 1.3 GHz SRF cryomodule, its performance without the beam and results of the system commissioning with high intensity electron beam at Fermilab Accelerator Science and Technology (FAST) facility are presented. We also briefly discuss opportunities for further beam studies and tests at FAST including those on even higher gradient and more efficient SRF acceleration, as well as exploration of the system performance with full ILC-type beam specifications.

Focusing Waveguide Structure for High-Gradient Electron Acceleration by Picosecond Terahertz Pulses

“…6. The energy gained by an electron in the accelerating structure for three values of the electron's initial energy: 45 keV (1), 50 keV (2), and 55 keV (3).…”

“…The achievement of high acceleration gradients, i. e., high amplitudes of accelerating fields, has remained for decades one of the problems the solution of which will ensure further progress in the physics of elementary particles and accelerators [1][2][3][4][5]. Among the classical accelerators operating in the range of decimeter and centimeter waves, the highest gradients (which correspond to the amplitude of the accelerating electric field at the level 100 MV/m) with a structure filling time of about 100 ns are currently demonstrated in normally conducting accelerating structures [1,2].…”

Nishikawa Prize article: Electron lenses, Tevatron, and selected topics in accelerators

“…As part of the FNAL Accelerator Physics Center (APC) mission (see below), since 2009 we constructed the Fermilab Accelerator Science and Technology (FAST) facility which beside the IOTA ring comprises a 300 MeV 1.3 GHz SC rf electron linac [27]. In the fall of 2017, we achieved the world record-high superconducting rf beam accelerating gradient of 31.5 MeV=m [67]-this was the first ever demonstration of an average beam accelerating gradient matching the specifications of the International Linear Collider (ILC). That accomplishment greatly boosted the confidence in the technical feasibility of the ILC-the supercollider project to push elementary particle physics beyond the LHC and which is now under serious consideration by the Japanese government.…”

Experience with crystals at Fermilab accelerators

“…Recently constructed Fermilab Accelerators Science and Technology (FAST) facility 12 hosted series of studies aimed to produce high brightness X-rays using a low-emittance 50 MeV electron beam, and to demonstrate that CR can be used as a compact high-brightness X-rays source 13,14 . The FAST injector 15 (see main parameters in Table 1) which consists of a CsTe photocathode located in a 1+1/2-cell RF gun followed by two L-band (1.3 GHz) superconducting accelerating structures can generate a low emittance electron beam. The electron energy can reach up to 50 MeV downstream of the last superconducting cavity.…”