Preliminary RF and Beam Data Analysis

Jeff Dooling

June 26, 2007

Summary of rf and beam data

• ISIS

• IPNS

ISIS RF Data2 cavities

—courtesy I. Gardner (Nov 2006)

1&2rf Total volts (2rf4,5)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

-10 -5 0 5 10 15 20

Time (ms)

Y-A

xis

(2RF)4,5

Delta

0

0.2

0.4

0.6

0.8

1

-2 0 2 4 6 8 10 12 14 16 18

Time (ms)

Y-A

xis

ISIS SH rf and near injection(2 cavities)

Delta

0

0.2

0.4

0.6

0.8

1

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Time (ms)

Y-A

xis

1&2rf Total volts (2rf4,5)

0

0.05

0.1

0.15

0.2

0.25

-1 -0.5 0 0.5 1 1.5

Time (ms)

Y-A

xis

2RF(4,5)

SH RF status

• September 2005 (no SH RF)Injected charge: 2.33x1013 protons

Captured charge: 2.07x1013 protons

Extracted charge: 2.04x1013 protons

• Dec 2006 (SH rf Superperiods 4 and 5)Injected charge: 2.78x1013 protons

Captured charge: 2.54x1013 protons

Extracted charge: 2.47x1013 protons

FFT analysis of ISIS single-ended BPM data (shortly injection)—fundamental RF only

fo = 1.388 MHz

FFT analysis of ISIS single-ended BPM data (near extraction)—fund. RF only

fo = 3.055 MHz

Results

• Capture efficiency improved substantially

• Total current to extraction up by 10%

• Would like to look at pulse shape evolution

• Are possible instabilities an issue later

IPNS RCS data

• Ferrite limits use to the first 4 ms

• Use always provides an improvement in current

• Other stability issues in the machine?

RCS RF data

Preliminary look at bunch shape with phase

Simple waveform analysis

Vertical instability later

Unstable bunches are shortened

Prelimary IPNS results

• Good response with SH angle

• Voltage ratio approximately 0.55

• Bigger fish to fry—instability