Upload
kiayada-rios
View
30
Download
4
Embed Size (px)
DESCRIPTION
On the Effect of Eddy Current Induced Field. Wanming Liu, Sergey Antipov and Wei Gai HEP, ANL. Conditions. Undulator: k=0.92, l u=1.15cm, 100m long Target: 0.4 r.l. Ti, 500m drift OMD:5T-0.25T,50cm - PowerPoint PPT Presentation
Citation preview
Conditions
• Undulator: k=0.92, u=1.15cm, 100m long
• Target: 0.4 r.l. Ti, 500m drift
• OMD:5T-0.25T,50cm
• Eddy current induced field: from Femlab simulation at 900rpm for 1m radius wheel of titanium under 5T magnetic field.
• Conductivity of target: 1.5e6 and 3e6
Bz of Induced field + OMD field near the target
z (mm)
Y
(mm
)
Distortion caused by eddy current induced field is observed near the target
By of OMD field on yz plane near the target
Beam axis
By of OMD field By of induced field
Transverse component of induced field is small comparing with those from OMD itself. It’s effective domain is a small vicinity near both the beam axis and target.
x-x’ comparison of captured positrons with and without induced field
Induced field kicked some out but also kicked some in. The final yield doesn’t change for =1.5e6
Initial x-x’ of captured positrons
Induced field kicked some positrons out but also kicked some in. The lost of yield is only ~5%( from ~1.27 down to ~1.20).
Summary
• For =1.5e6, since the eddy current induced field is small comparing with the OMD field, and also due to the broad band matching provided from OMD field, the distortion of field doesn’t caused any noticeable change to the e+ yield.
• For =3e6, the eddy current induced field is nearly twice as much as of =1.5e6 and we noticed a lost of yield of about 5%( from ~1.27 down to ~1.20).
• Lower the conductivity will suppress the effect eddy current induced field.