P.N. Burrows BDS/MDI, LCWS08 Chicago, 17/11/08

1

Beam-based feedback for LC

• ILC luminosity goal 10**34 / cm**2 / s

3000 or 6000 bunches, spacing 150 - 300ns

DIGITAL FB approach

• CLIC luminosity goal 10**35 / cm**2 / s

c. 100 bunches, spacing c. < 1ns

ANALOGUE FB approach

P.N. Burrows BDS/MDI, LCWS08 Chicago, 17/11/08

2

e-

e+

IP beam-based feedback for LC

P.N. Burrows BDS/MDI, LCWS08 Chicago, 17/11/08

3

Kicker BPM 1

Digital feedback

Analogue BPM processor

Driveamplifier

BPM 2

BPM 3

e-

FONT4 ILC prototype at KEK/ATF

3 bunches, 140-154ns spacing

1.3 GeV

P.N. Burrows BDS/MDI, LCWS08 Chicago, 17/11/08

4

Kicker BPM 1

Digital feedback

Analogue BPM processor

Driveamplifier

BPM 2

BPM 3

e-

FONT4 ILC prototype at KEK/ATF

P.N. Burrows BDS/MDI, LCWS08 Chicago, 17/11/08

5

Example (1) of May 2008 Results

low gain medium gain

high gain

P.N. Burrows BDS/MDI, LCWS08 Chicago, 17/11/08

6

Example (3) of May 2008 Results

Slack = 22 ns

Latency

= 154 - slack

= 132 ns

+ 8ns (1/Q)

Bunch 1

Kicker pulse

Bunch 2154ns

Latency Slack

Latency measurement