An advanced magnetic chicane bunch compressor has been installed at the ATF that will produce short and/or energy chirped bunches. The compressor itself is an experimental object, where the effects of coherent synchrotron radiation and non-inertial space-charge forces. In the context of this project, the compressed beam will be used in ATF beamline 3, to inject an ultra-short, high brightness electron beam into the VISA undulator, driving a SASE FEL into saturation in less than 3 m.
Future studies characterizing the CSR/CER emitted between the third and fourth magnets are on going.
Rendering of the full ATF compressor system |
Phase spaces, emittances and twiss parameters of interest |
Longitudinal Phase Space |
Current Profiles |
Bunch Length Evolution / Spot Size |
***With the CSR turned on*** | |||||
property | Initial Beam | Final Beam | |||
current | 40-45 amps | 1.5Kamps | |||
emit, x | 1.45 mm-mrad | 1.49 mm-mrad | |||
emit, y | 1.47 mm-mrad | 5.755 mm-mrad | |||
X, rms | .39 mm | .14mm | |||
Y, rms | .39 mm | .14mm | |||
length, rms | 400 microns | 24 microns | |||
beta x | 15 m | 1.9 m | |||
beta y | 15 m | 1.9 m | |||
alpha x | -1 | 7.00E-12 | |||
alpha y | -1 | -0.77 | |||
***With the CSR turned off*** | |||||
property | Initial Beam | Final Beam | |||
current | 40-45 amps | 1.5Kamps | |||
emit, x | 1.45 mm-mrad | 1.49mm-mrad | |||
emit, y | 1.47 mm-mrad | 3.12mm-mrad | |||
X, rms | .39 mm | .14mm | |||
Y, rms | .39 mm | .188mm | |||
length, rms | 400 microns | 257 microns | |||
beta x | 15 m | 1.9 m | |||
beta y | 15 m | 1.9 m | |||
alpha x | -1 | 7.00E-12 | |||
alpha y | -1 | -0.77 | |||
The above parameters and the attached plots are all either taken from the beginning | |||||
of the H-line or at the entrance to the dogleg. The one exception is the spotsize | |||||
plot which is shown at the symmetry point of the compressor. |