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Brief summary of run #9 (16-18 September). Shinji Machida o n behalf of the beam commissioning team ASTeC /STFC/RAL 21 September 2010. Aims. Capture a beam in a bucket and observe synchrotron oscillations . Understand “improvement” by QD27.
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Brief summary of run #9 (16-18 September) Shinji Machida on behalf of the beam commissioning team ASTeC/STFC/RAL 21September 2010
Aims • Capture a beam in a bucket and observe synchrotron oscillations. • Understand “improvement” by QD27. • Establish nominal lattice with less QD/QF ratio.
rf frequency • Change rf frequency from 1.3 GHz to 1.301 GHz. • Synchronize with revolution frequency. • Can inject a beam into the centre of rf bucket.
Slippage factor • By measuring ToF at 18.5 and 16.5 MeV/c, slippage factor can be calculated. dt/t =\eta dp/p \eta = dt/dpp/t = 7.7 e-3
rf voltage • Synchrotron oscillation frequency tells rf voltage a beam sees • With 1 MV, oscillation period should be 14 turns. • Observed period is 20 turns. • Therefore, a beam only sees 0.5 MV.
Momentum acceptance • Large amplitude synchrotron oscillation is not allowed especially when a beam is decelerated. • Momentum acceptance limit is -1.3 MV (equiv.) • More on positive side.
Next step • Measurement of individual phase. • Measurement of closed orbit and correction. • Measurement of injection orbit.