Paper |
Title |
Other Keywords |
Page |
CT04 |
Bunch Length Measurements in LEP
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pick-up, synchrotron, photon, monitoring |
59 |
|
- A.J. Burns, H. Schmickler
CERN, Geneva, Switzerland
|
For many years a streak camera has been used for
observing the longitudinal distribution of the particles in
any LEP e+ or e- bunch (5-50 ps r.m.s. length) on a turn
by turn basis, using synchrotron light. In 1996, a
comparison made with the longitudinal vertex
distributions of 3 LEP experiments allowed the
identification and elimination of certain systematic errors
in the streak camera measurements. In 1997, a new bunch
length measurement technique was commissioned that
uses the high frequency slope of the bunch power
spectrum from a button pickup. In 1998, this new method
was confronted with measurements from the streak
camera and the LEP experiments. The measurements
made in 1996 and 1998 are presented, with emphasis on
the calibration of the two instrumental methods and their
respective precision and limitations.
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PS16 |
The fast head-tail instability suppression in multibunch mode at VEPP-4M
|
feedback, injection, kicker, dipole |
138 |
|
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|
PT19 |
A method for measurement of transverse impedance distribution along storage ring
|
pick-up, betatron, vacuum, storage-ring |
202 |
|
- V. Kiselev, V. Smaluk
BINP, Budker Institute of Nuclear Physics, Novosibirsk, Russia
|
A new method for measurement of transverse couple
impedance distribution along storage ring is described.
The method is based on measuring of a closed orbit
deviation caused by local impedance. Transverse
impedance acts on the beam as a defocusing quadrupole,
strength of which depends on the beam current. If a local
bump of closed orbit has been created at the impedance
location, then the orbit deviation occurs while varying
the beam current. The local impedance can be evaluated
using the orbit deviation measured. Measurement
technique is described, the method accuracy is
evaluated. The method described was successfully used
for measurement of the impedance distribution along the
VEPP-4M storage ring.
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