1) Jitter and Phasenoise

2) Devices

3) simulation

Jitter is a measurement of the variations in the time domain, and essentiallydescribes how far the signal period has wandered from its ideal value.Typically, deviations below 10 MHz are not classified as jitter, but as wanderor 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!

Absolute jitter: It is given by the sum of each periods variation from the averagePeriod jitter:simply 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:

Phasenoise:

Measuring phasenoise

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= ”‘slow”’drifts are not of importance.

What are our frequency - boundaries?

TTC (Timing, Trigger and Control) is only the delivery system: Info about timing to beam?

Pulsed BBLR:

Load: L = Zin/2f of 840nH.

Design strategy

1) 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:

Transitor:polyfet rf devices - F1401

Gatedriver: IXYS- IXDD415SI

-spice models avaiable, to be tested.

Simulations: SPS – DA as function of beam-wire distance - which law?

The simulated dependance on the beam-wire distance is fitted by y = a*x^b + c, where a = 0.188, b = 1.836, c = 0.06768

-> The dependance always follows a power law.

- > Can we make test the power law in the SPS at different tunes?

Experiment Simulation

2005 – injection

Instabilities found

Sextupoles inportant

Instabilities found

2006 –store

Doubtfull

No instabilities

“hard” to produce

RHIC

No sextupoles

Blue beam - L45, LR(s=0), t-comp, Qx=28.733, Qy=29.722

including sextupoles

Tune from one turn map ( included in BBTrack 5.3.0.3)

Example: an instable particle

Is the tune difference a valid Lyaponov-function?

-> seams easier to detect.

- What are the frequencies?

Chromaticity=0, no sextupoles, offmomentum

Next steps

- Chromaticity tuneshift?

-Tune variation fue to coupling

-….