Precision Control of the Electron Longitudinal Bunch Shape Using an Emittance-Exchange Beam Line.
We report on the experimental generation of relativistic electron bunches with a tunable longitudinal bunch shape. A longitudinal bunch-shaping (LBS) beam line, consisting of a transverse mask followed by a transverse-to-longitudinal emittance exchange (EEX) beam line, is used to tailor the longitudinal bunch shape (or current profile) of the electron bunch. The mask shapes the bunch's horizontal profile, and the EEX beam line converts it to a corresponding longitudinal profile. The Argonne wakefield accelerator rf photoinjector delivers electron bunches into a LBS beam line to generate a variety of longitudinal bunch shapes. The quality of the longitudinal bunch shape is limited by various perturbations in the exchange process. We develop a simple method, based on the incident slope of the bunch, to significantly suppress the perturbations.
POSTECH, Pohang, Gyeongbuk 37673, Republic of Korea.
G
G
Ha
POSTECH, Pohang, Gyeongbuk 37673, Republic of Korea.
M H
MH
Cho
POSTECH, Pohang, Gyeongbuk 37673, Republic of Korea.
W
W
Namkung
Argonne National Laboratory, Argonne, Illinois 60439, USA.
J G
JG
Power
Argonne National Laboratory, Argonne, Illinois 60439, USA.
D S
DS
Doran
Argonne National Laboratory, Argonne, Illinois 60439, USA.
E E
EE
Wisniewski
Argonne National Laboratory, Argonne, Illinois 60439, USA.
M
M
Conde
Argonne National Laboratory, Argonne, Illinois 60439, USA.
W
W
Gai
Argonne National Laboratory, Argonne, Illinois 60439, USA.
W
W
Liu
Argonne National Laboratory, Argonne, Illinois 60439, USA.
C
C
Whiteford
Argonne National Laboratory, Argonne, Illinois 60439, USA.
Q
Q
Gao
Argonne National Laboratory, Argonne, Illinois 60439, USA.
K-J
KJ
Kim
Argonne National Laboratory, Argonne, Illinois 60439, USA.
A
A
Zholents
Argonne National Laboratory, Argonne, Illinois 60439, USA.
Y-E
YE
Sun
Euclid TechLabs, Solon, Ohio 44139, USA.
C
C
Jing
Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
P
P
Piot