The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF
AU - Turner, M.
AU - Gschwendtner, E.
AU - Lotov, K.V.
AU - Petrenko, A.V.
AU - Sosedkin, A.
ED - Schaa, Volker RW
ED - Power, Maria
ED - Shiltsev, Vladimir
ED - White, Marion
TI - Proton Beam Defocusing as a Result of Self-Modulation in Plasma
J2 - Proc. of NAPAC2016, Chicago, IL, USA, October 9-14, 2016
C1 - Chicago, IL, USA
T2 - North American Particle Accelerator Conference
T3 - 3
LA - english
AB - The AWAKE experiment will use a 400 GeV/c proton beam with a longitudinal bunch length of sigmq_{z} = 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 n_{p}e = 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 n_{p}e = 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.
PB - JACoW
CP - Geneva, Switzerland
SP - 707
EP - 709
KW - proton
KW - ion
KW - plasma
KW - wakefield
KW - focusing
DA - 2017/01
PY - 2017
SN - 978-3-95450-180-9
DO - 10.18429/JACoW-NAPAC2016-WEPOA09
UR - https://jacow.org/napac2016/papers/wepoa09.pdf
ER -