Jitter and Phasenoise

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1. Jitter and Phasenoise
2. Devices
3. simulation

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Jitter is a measurement of the variations in the
time domain, and essentially describes how far
the signal period has wandered from its ideal
value. Typically, deviations below 10 MHz are not
classified as jitter, but as wander or drift.
Phase noise is a frequency-domain view of the
noise spectrum around the oscillator signal,
while jitter is a timedomain measure of the
timing accuracy of the oscillator period
Problem There exist many similar definitions
same word describes different things!
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Absolute jitter It is given by the sum of each
periods variation from the average Period
jittersimply measures the period of each clock
cycle in the waveform
Cycle-to-cycle jitter This is the jitter
definition that most people mean when they talk
about jitter as a single number. It measures the
variance of each period to the average period
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Phasenoise
Measuring phasenoise
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Translating between phasenoise and jitter
The total noise power of the sidebands can be
determined by integrating the L(f) function over
the band of interest - in this case, 12 KHz to 10
MHz. This might be for example be the case if low
frequency noise slowdrifts are not of
importance.
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• What are our frequency - boundaries?
• TTC (Timing, Trigger and Control) is only the
  delivery system Info about timing to beam?

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Pulsed BBLR
Load L Zin/2f of 840nH.
Design strategy
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• Remo Maccaferri
• has specs, thinking of avalache devices (as
  far as I know) advantage high current, fast
  switching, disadvantage lifetime, fuzzy status,
  problematic to turn off
• 2) M. Paoluzzi
• - no avalanche devices (fuzzy state, but knows
  he is no expert on them)
• - he thinks its possible to meet the specs
  with
• Transitorpolyfet rf devices - F1401
• Gatedriver IXYS- IXDD415SI
• -spice models avaiable, to be tested.

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Simulations SPS DA as function of beam-wire
distance - which law?
The simulated dependance on the beam-wire
distance is fitted by y axb c, where a
0.188, b 1.836, c 0.06768 -gt The dependance
always follows a power law.
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- gt Can we make test the power law in the SPS at
different tunes?
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RHIC
Experiment Simulation
2005 injection Instabilities found Sextupoles inportant Instabilities found
2006 store Doubtfull No instabilities hard to produce
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Blue beam - L45, LR(s0), t-comp, Qx28.733,
Qy29.722
No sextupoles
including sextupoles
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Tune from one turn map ( included in BBTrack
5.3.0.3)
Example an instable particle
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Is the tune difference a valid Lyaponov-function?

• -gt seams easier to detect.
• What are the frequencies?

Chromaticity0, no sextupoles, offmomentum
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• Next steps
• Chromaticity tuneshift?
• Tune variation fue to coupling
• .