em simulation of wakes in bsrt beampipe with extraction mirror
DESCRIPTION
EM Simulation of wakes in BSRT beampipe with extraction mirror. Tool : Time domain solver of ACE3P Suite. Crosscheck with CST Particle Studio. Andriy Nosych / CERN BE-BI-QP Impedance meeting / 25 June 2012. Simplified BSRT model is considered. (BSRT complete assembly). - PowerPoint PPT PresentationTRANSCRIPT
EM Simulation of wakes in BSRT beampipe with extraction mirror
Tool: Time domain solver of ACE3P Suite.Crosscheck with CST Particle Studio.
Andriy Nosych / CERN BE-BI-QPImpedance meeting / 25 June 2012
Simplified BSRT model is considered
Mirror front
(BSRT complete assembly)
Beam
22 mm
Mirror back (most likely coated)
Silicon
Excitation:
Single bunch with Gaussian charge distributionCharge = 1.7e-8 CBunch length: 0.3 m / 1 ns / [-4s, 4s]s = 40 mm / 130 picosecondsBunch transverse size: point
Wake potential along beam axis
Simulated mirror modifications @ ACE3P
Silicon mirror (eps = 11.9,el.cond=2.5e-4)
Silicon + coated mirror (by putting an electric boundary on back surface)
Stainless-steel mirror
Simulated mirror modifications @ ACE3P
Coated/Steel mirror have a resonant mode at around 658-670 MHz
Harmonics?
Silicon mirror (eps = 11.9,el.cond=2.5e-4)
Silicon + coated mirror (by putting an electric boundary on back surface)
Stainless-steel mirror
Crosscheck with CST Particle Studio (coated mirror sample)
Full assembly VS. Simplified assembly
Full assembly peak at: 640 MHzSimplified peak at: 655 MHz
First test run with 3-bunch train (Steel mirror sample) @ ACE3P
Peak at 670 MHz
E-field Magnitude @ ACE3P + E-field probe along white line (mirror edge)
“Old” simplified mirror support
“New” complete mirror support assembly
Mirror in
Beam-mirror: 22 mm
Mirror out
Beam-mirror: 50 mm
“Ferrite” ring (made of Steel so far, can not simulate ferrite)
Additional cavities behind mirror support.
Full electric contact between washer and body. Thus no vacuum considered behind washer.
CONCLUSIONS:
With a complete model of a mirror support, the resonating mode frequency shifts to 600 MHz.
No big difference between resonances with the mirror
“in” and “out”.
UPDATE