Synchrotron Radiation Source R&D at BESSY II in Berlin
Synchrotron Radiation Source R&D at BESSY II in Berlin
Synchrotron Radiation Source R&D at BESSY II in Berlin
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vertical tune shift<br />
0,07<br />
0,06<br />
0,05<br />
0,04<br />
0,03<br />
0,02<br />
0,01<br />
0,00<br />
Wiggler Implement<strong>at</strong>ion <strong>in</strong> <strong>BESSY</strong> <strong>II</strong><br />
♦ e-beam can be <strong>in</strong>jected <strong>at</strong> max. field<br />
but: strong lifetime degrad<strong>at</strong>ion<br />
♦ Nonl<strong>in</strong>ear field components are small<br />
♦ However: tune shift and β-be<strong>at</strong> disturb<br />
nonl<strong>in</strong>ear tun<strong>in</strong>g and reduce dynamic<br />
aperture, → must be compens<strong>at</strong>ed<br />
♦ Compens<strong>at</strong>ion method: tune the Q-pole<br />
pairs <strong>in</strong>dividually <strong>in</strong> all straight sections<br />
such th<strong>at</strong><br />
►<br />
- nom<strong>in</strong>al tune is restored,<br />
- β-be<strong>at</strong> is m<strong>in</strong>imized,<br />
- β function phase error is kept<br />
localized <strong>at</strong> the wiggler straight sec.<br />
Residual degrad<strong>at</strong>ion of lifetime<br />
only ~ 15%<br />
HMI-Multipole-Wiggler<br />
tune shift<br />
~ B**2<br />
0 1 2 3 4 5 6 7<br />
wiggler field [T]<br />
87,5<br />
75,0<br />
62,5<br />
50,0<br />
37,5<br />
25,0<br />
12,5<br />
0,0<br />
bet<strong>at</strong>ron frequency shift [kHz]<br />
E:user:berger:e<strong>in</strong>fahren042003:tuneshift.op<br />
β-funtion phase difference with<br />
- global correction only (red)<br />
- local tune compens<strong>at</strong>ion (black)<br />
4th N<strong>at</strong>. Congress on Particle Acceler<strong>at</strong>ors and Applic<strong>at</strong>ions / Bodrum / Turkey 30.8. – 1.9. 2010 Ernst Weihreter / HZB <strong>BESSY</strong> <strong>II</strong><br />
16
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