LLRF Tuning System Results

BySaad AlSari

SEP 22th 2010

ESS-Bilbao Tuning System•System Overview

The system parts been set up in Imperial College with the signal generator and high power amplifier in the input end and the stepper motor drive, the RFQ tuner on the RFQ could model from the other end.

System performing amplitude, phase and tuning control.

The LLRF system includes three feedback loops to regulate the amplitude and phase of the RFQ field as well as the RFQ resonance frequency.

The equipments worked without modifications apart from optimizing settings of the LLRF parameters using the provided GUI input settings.

ESS-Bilbao Tuning SystemSystem Setup

A laptop with PCI Express port interface would be needed in the current Matlab control terminal.

•The FPGA interface with the laptop might malfunction if any of these requirements is not met:

• Manufacturer: Dell or Hewlett Packard (HP)• Operating System: Microsoft Windows XP Professional• Service Pack 2• Express Card for compact PCI connection

ESS-Bilbao Tuning SystemSystem Results

Main Parameters Date: 6, 7 September 2010

Pulse Parameters:

PARAMETER Specification Low Power Test 60 Watt Test UNIT NOTE

Pulse frequency 50 49.64 49.64 Hz

Pulse width 2 1.989 1.989 ms

Duty cycle 10 9.873 9.873 %

Settling time <100 7 86 us

RFQ cold model Parameters:

PARAMETER Specification Measured   UNIT NOTE

fcav 324 320.35 MHz

Tuning range 1 app. MHz with 4 tuners

Q (unloaded) measured 9000 7773

LLRF Parameters:

PARAMETER Specification Low Power Test 60 Watt Test UNIT NOTE

Operation mode CW / pulsed CW / pulsed CW / pulsed

Settling time <100 <100 <100 usdepends on PI gain Adjustments

ESS-Bilbao Tuning SystemSystem Results• System operated in pulsed mode (pulse rate = 50 Hz, pulse width = 2 ms)

LOW POWER TESTS 60 WATTS TESTS

•Fig. 1:Pulse parameters : Measured cavity field and Sink of 50 Hz

•Fig. 1:Pulse parameters : Measured cavity field and Sink of 50 Hz

ESS-Bilbao Tuning SystemSystem Results• System operated in pulsed mode (pulse rate = 50 Hz, pulse width = 2 ms)

LOW POWER TESTS 60 WATTS TESTS

•Fig. 2 :Settling time of measured cavity field •Fig. 2 :Settling time of measured cavity field

ESS-Bilbao Tuning SystemSystem Results• System operated in pulsed mode (pulse rate = 50 Hz, pulse width = 2 ms)

LOW POWER TESTS 60 WATTS TESTS

•Fig. 3: CW operation . Measured cavity field and reference signal (generator output)

•Fig. 3: CW operation . Measured cavity field and reference signal (generator output)

ESS-Bilbao Tuning SystemSystem Results• System operated in pulsed mode (pulse rate = 50 Hz, pulse width = 2 ms)

60 WATTS TESTS

•Fig. 4: Measured cavity field and reflected power

ESS-Bilbao Tuning SystemSystem Results• System operated in pulsed mode (pulse rate = 50 Hz, pulse width = 2 ms)

LOW POWER TESTS

ESS-Bilbao Tuning SystemSystem Results• System operated in pulsed mode (pulse rate = 50 Hz, pulse width = 2 ms)

60 WATTS TESTS