8 research outputs found
Vibrating Wire for Beam Profile Scanning
The method for measurement of transverse profile (emittance) of the bunch by
detecting of radiation arising scattering at of the bunch on the scanning wire
is wide-spread. In this work the information about scattering bunch is proposed
to measure using the oscillation frequency of the tightened scanning wire. In
such way the system of radiation (or secondary particles) extraction and
measurement can be removed. Dependence of oscillations frequency on beam
scattering is determined by several factors, including changes of wire tension
caused by transverse force of the beam, influence of beam self field.
Preliminary calculations show that influence caused by wire heating will
dominate. We have studied strain gauges on the basis of vibrating wire from
various materials (tungsten, beryl bronze, niobium zirconium alloys). A scheme
of self oscillations generation by alternating current in autogeneration
circuit with automatic frequency adjustment was selected. Special method of
wire fixation and elimination of transverse degrees of freedom allow to achieve
relative stability better than 1E-5 during several days. For a tungsten wire
with a fixed end dependence of frequency on temperature was 1E-5/K.
Experimental results and estimates of wire heating of existing scanners show,
that the wire heats up to a few hundred grades, which is enough for
measurements
Large aperture vibrating wire monitor with two mechanically coupled wires for beam halo measurements
Development of a new type of vibrating wire monitor (VWM), which has two mechanically coupled wires (vibrating and target), is presented. The new monitor has a much larger aperture size than the previous model of the VWM, and thus allows us to measure transverse beam halos more effectively. A prototype of such a large aperture VWM with a target wire length of 60 mm was designed, manufactured, and bench-tested. Initial beam measurements have been performed at the Fermilab High Intensity Neutrino Source facility, and key results are presented.open1
Vibrating wire scanner: First experimental results on the injector beam of the Yerevan synchrotron
This paper presents the first experimental results of the transverse profile measurements using a vibrating wire scanner at the Yerevan synchrotron injector electron beam (6 nA after collimation). The advantage of this novel technique is that there is no need for secondary radiation or particle detectors. The local beam intensity is measured using the natural oscillation frequency of the wire, which is a function of the wire temperature