CERN, Geneva, Switzerland
CSU, Fort Collins, Colorado, USA
Texas A&M University, College Station, USA
NSCL, East Lansing, Michigan, USA
UCLA, Los Angeles, California, USA
DESY Zeuthen, Zeuthen, Germany
UNIST, Ulsan, Republic of Korea
JAI, Oxford, United Kingdom
SBU, Stony Brook, New York, USA
MSU, East Lansing, Michigan, USA
We report here the results of a one week long investigation into the conceptual design of an X-ray source based on a compact ring with on-orbit and on-energy laser-plasma accelerator (mini-project 10.4 from [1]). We performed these studies during the June 2016 USPAS class "Physics of Accelerators, Lasers, and Plasma…" applying the art of inventiveness TRIZ. We describe three versions of the light source with the constraints of the electron beam with energy 1 GeV or 3 GeV and a magnetic lattice design being normal conducting (only for the 1 GeV beam) or superconducting (for either beam). The electron beam recirculates in the ring, to increase the effective photon flux. We describe the design choices, present relevant parameters, and describe insights into such machines.
[1] Unifying physics of accelerators, lasers and plasma, A. Seryi, CRC Press, 2015.
CERN, Geneva, Switzerland
Budker INP & NSU, Novosibirsk, Russia
The AWAKE experiment will use a 400 GeV/c proton beam with a longitudinal bunch length of sigmqz = 12 cm to create and sustain GV/m plasma wakefields over 10 meters. A 12 cm long bunch can only drive strong wakefields in a plasma with npe = 7 x 1014 electrons/cm3 after the self-modulation instability (SMI) developed and microbunches formed, spaced at the plasma wavelength. The fields present during SMI focus and defocus the protons in the transverse plane. We show that by inserting two imaging screens downstream the plasma, we can measure the maximum defocusing angle of the defocused protons for plasma densities above npe = 5 x1014 electrons/cm3. Measuring maximum defocusing angles around 1 mrad indirectly proves that SMI developed successfully and that GV/m plasma wakefields were created. In this paper we present numerical studies on how and when the wakefields defocus protons in plasma, the expected measurement results of the two screen diagnostics and the physics we can deduce from it.