1' batch by batch intensity measurement using the damper system 2' damper system transverse e measur

1
1. batch by batch intensity measurement using
the damper system2. damper system transverse e
measurement
2
212 MHz Sampling of RWM signal using the
longitudinal damper
By adding the bunch intensity of all bunches in a
batch we can measure the beam intensity
3
Implement firmware code for the damper system to
measure beam intensity of each beam batch using
the long. damper
DDZBK0 (ACNET device) --gt set this variable
equal to the first bucket
Begin the bunch intensity measurement at bunch
DDZBB1 (numbered relative to DDZBK0 )
-- NUMI Signal Accumulator control
pulses ()NUMI_BB1 dff(.clkadclkby2,
.dbucket_count.qreg_DDZBB1.q) -- pulses
on bucket to capture for ACNET ()NUMI_BB2
dff(.clkadclkby2, .dbucket_count.qreg_DDZBB2
.q)
End the bunch intensity measurement at bunch
DDZBB2 (numbered relative to DDZBK0 )
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-- NUMI SIGNAL Accumulators to calc sum of I
signals over specified range of
Bunches ------------------------------------------
-------------------------------------------- --
accumulators big enough to width allows gt588
accums w/o overflow. -- Reset once per turn at
bunch programmable via NUMI_BB1 -- via ".sload"
port which loads first sample (instead of adding
it in) () NUMI_accI altaccumulate
(.clockadclkby2, .sloadNUMI_BB1, .data
Ich0.q) with (WIDTH_IN16, WIDTH_OUT26,
LPM_REPRESENTATION"SIGNED") returns(.result0)
-- Output holding registers to capture I totals
up to at end of each turn for ACNET display --
holding registers for VME/ACNET readout of 1-turn
sum ()reg_DDZBIS lpm_ff(.clockadclkby2,
.enableNUMI_BB2, .data NUMI_accI.result)
with (LPM_WIDTH26) returns(.q0)
Output the integrated bunch intensity
measurement

• Works fine with one batch
• Need to be tested with multi batches

5
Transverse e change with the damper working on
the beam
Vertical and horizontal trans. e are measured
using flying wires
Transverse e is measured right after the beam
injection into the MI at 8 GeV
Beam intensity
Vertical wire
Horizontal wire
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Measured trans. e with different injection
errors (damper off)
With steering injection error by a
Lambertson Values of e 12.0 (V) 16.21 (H)
With normal injection error Values of e 10.93
(V) 10.85 (H)
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Observed transverse bunch oscillation using the
damper system with the mis-steered injection
big oscillations for many turns
Horizontal
Vertical
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Oscillation of mis-steered beam with the damper
on the beam is damped down very quickly
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Measured trans. e with the damper on when beam is
mis-steered

• Value of trans. e with damper on
• Normal injection avg. 9.88 (V) 9.28 (H)
• ?damper off avg. 10.93 (V) 10.85
  (H)
• Big injection error avg. 10.07 (V) 8.96 (H)
  
• ? damper off avg. 12.0 (V) 16.21
  (H)

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However there is not a big change in trans. e
measured at 120 GeV need more measurements to
understand
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Conclusion plan

• Need to test the newly implemented codes for
  measuring beam intensity batch by batch for multi
  batches
• Significant trans. e reduction at injection is
  observed with the damper on
• transverse damper works well