Summary Report
S. Machida
KEK, Tsukuba, Japan
Experiment at the KEK PS Main Ring
S. Igarashi
ferrite impedance were measured and the impedance reduction at 130 deg C was confirmed.
Beam profiles were measured at different vertical bare
tunes and clear broadening is observed when the bare
tune is approaching integer 7. As a function of time,
the profile is also measured 3 ms after injection and
compared with the ACCSIM simulation. Both agree with
each other quite nicely when the horizontal bare tune
is 7.05. The ACCSIM simulation clearly identifies the
octupole resonance that produces the broadening.
Flattening of Bunch shape with Longitudinal Hollow
Distribution at the CERN PSB
C. Carli
Experiment at the KEK PS Booster
/. Sakai
Since the bare tune of the booster is (2.17, 2.32), just
above the coupling resonance of 2nx — 2ny = 0, space
charge forces may induce emittance exchange. Experimentally, that was observed when the beam intensity is
increased. Emittance evolution in the first 1 ms is measured and compared with Simpsons. The result confirms
that space charge is the source of the exchange, at least
qualitatively.
Experiment at PSR
S. Cousineau
Beam broadening has been observed both experimentally
and in ORBIT simulations. An analysis based on coherent resonance theory is presented. RMS emittance is observed as a function of several parameters such as longitudinal charge distribution and vertical bare tune. The
results between theory and simulation are indeed consistent.
Measurement of the PSR Inductive Insert Ferrite
Material Characteristics
K.-Y.Ng
Although the first attempt of using an inductive insert at
PSR to cancel the longitudinal space charge force was
successful, longitudinal microwave instabilities were observed when the bunch length is shortened. Microwave
instabilities were subsequently suppressed by heating the
ferrite to 130 deg C.The real and imaginary part of the
Initially, a scheme employing RF gymnastics with complicated control of phase and amplitude of the first and
second harmonics was envisioned to create a hollow
bunch. Simulation confirmed that a hollow bunch would
indeed be created as expected; however the scheme was
difficult to implement. Studies subsequently led to an
improved procedure which keeps the first harmonic RF
voltage constant and involves less RF gymnastics of the
other parameters. Experimentally, this improved procedure was employed. The resulting distribution was measured using a tomographic technique and confirmed that
the creation of hollow bunches by redistribution of phase
space is possible.
Measurement of the PSI Beam
A. Adelmann
Transverse beam profiles were measured in the beam line
and in the cyclotron. Simulation with space charge with
MAD9P is generally in agreement, however, but at some
locations, the measurement results slightly deviate from
what the code predicts. A possible explanation is that
while neutralization is expected to vary, the calculations
assumed it to be constant.
Current Status of Beam Experiments at the
University of Maryland, Including Electron Ring
and 5-beamlet Experiment
R. Kishek
The University of Maryland Electron Ring (UMER) is
currently under construction and should be completed in
a year or so. The goal is to provide a research platform for
high intensity, space-charge dominated beams. Recently,
an energy analyzer with a 10~4 resolution has been developed.
CP642, High Intensity and High Brightness Hadron Beams: 20th ICFA Advanced Beam Dynamics Workshop on
High Intensity and High Brightness Hadron Beams, edited by W. Chou, Y. Mori, D. Neuffer, and J.-F. Ostiguy
© 2002 American Institute of Physics 0-7354-0097-0/02/$ 19.00
299