PPT Slide

2?z? 15 cm

Qb? 2 × 10-8 C

r ? 6 mm

Detector box

E < 1V/m (?)

Peak E-field on inside surface for moving bunch:

Epeak = ? 3.4 × 109 V/m

E-field for fundamental harmonic (n=1, 40 MHz):

En=1 ? Epeak / 21 ? 1.6 × 108 V/m

For condition E < 1 V/m we need skin attenuation of about 108.

In fact, about 19 skin depths !!

?(Al, 40 MHz) ? 13.3 ?m ? foil thickness > 250 ?m !!

RF field attenuation

? · Qb

2?3/2 ?0 · ?z ·r

For non-cylindrical complex geometry, EM fields will be even higher.

? ? 7500