Study description
This is a summary of measurements of beam transmission vs beam
intensity vs quad current in the Booster. The location and width of
traversed resonances (dip in transmission) is extracted and plotted vs
beam intensity. Space charge
effects should change the location of the dip. Since these effects
depress the beam tune, a higher quad strength should be required to
drive the same resonance (see FNAL EXP-67, September 1974, for a
similar measurement done with the Main Ring). A preliminary analysis
indicates a tune shift Deleta_nu_x on the order of 0.04 between 1 and 9
turns of injected beam in the Booster.
Data set description
The data were collected on the 30th of January. The Booster
was running DC, the beam was captured at ~38 MHz with 4 RF stations on.
Studiers: J. Amundson, D. McGinnis, B. Pellico, and P. Spentzouris.
We measured transmission
(CHG1, CHG2) vs QL and QS
settings for different beam current (number of injected turns) in the
machine.
The tune was measured and the program calibrated (tune vs QL and QS)
for 1 injected turn.
Data header (1 turn dataset,
tune vs current calibration point)
Reset
$17
Snap flag
Min E12 0.100000
Max Qx 0.250900
Min Qx -0.249100
Num Qx 20
Max Qy 0.187600
Min Qy -0.312400
Num Qy 20
Qx0
0.749100
Qy0
0.812400
dIQL
-0.100000
dQxdIQL -0.010000
dQydIQL 0.024900
dIQS
-0.100000
dQxdIQS -0.043200
dQydIQS 0.006600
We recorded: dQx, dQy, dIQS, dIQL, pdcs, chg1, chg2, for
20×20 Qs, QL current values.
Results: tune
shift vs injected beam
current (data,
Synergia
prediction)
The tune shift is inferred from
driving the vertical
half-integer resonance for different beam currents.
Surface and Contour plots of
absorption (1-chg1/pdcs) vs tune
One, two, three, and nine turns in the machine. The plots
show absorption vs tune,
where the tune is calculated using the one turn calibration.
The integer and half integer tunes appear
to move and broaden, because the IQL=IQS=0 tune shifts from its one
turn
injected (calibration) value.
One and nine turns with SS at 0.044 amps
One and nine turns with SS as above, no harmonic sextupoles
One and nine turns as above with additional condition normal sextupols
off
As above, dog leg -300 amps.
Last
updated 2/06/03 by P. Spentzouris