Stripline Kicker Project

LBL

LLNLSLAC

KEK

DESY

Damping Ring Injection / Extraction Kicker Magnet

1) The TDR Kicker:1) 0.6 mrad (.01Tm), 5GeV, 50 m β, 7e-4 stability, 20 each, many meters

long (kicker ‘achromat’ not possible)2) Counter-fed 50 ohm striplines

2) The ‘conventional’ approach (~SLAC)1) Follow and extend the TDR design2) FET / Hard tube / Saturable Ferrite

3) Alternatives:1) Coherent sum CW standing wave kickers (system) – Gollin / KEK2) Waveguide close to cut-off (system) – Gollin / FNAL3) Pulsed traveling wave RF structures (system) – INFN / Cornell4) Shorted-striplines (just the magnet) – Wille (Dortmund) / SPEARIII5) (Hard tube-based pulsers – Frisch)

Consider the application of this technology at KEK-ATF

Counter-fed Stripline(power fed parallel to beam direction gives no kick unless v_g is low)Rise time depends on travelling wave kicker fill time

DESY Kicker RD

Rummler / Shiltsev / BINP

DESY Kicker RD

ITRP Poster (Obier)

(read µ)

DESY Kicker RD – 2 stripline magnets built

Ongoing RD for XFEL switchyard

ATF Kicker development. (2 programs)Program 1 – Conventional pulse technology extremely fast kicker:

Extract ~ 20 bunches spaced by 330 ns; to be used for testing ILC instrumentation in the ATF extraction line

Replace existing extraction kicker for test

25mm aperture, 20KV, 1.3m kicker is enough to extract (3mrad at 1.3GeV)(500A, 10MW peak)

Six 200 mm long stripline pairs - 12 pulsers ($/¥)

Conventional solid state / planar triode pulser with many counter-fed striplines

Roughly 2x harder than ILC

Uses saturable ferrite ‘shock-line’ technology

Program 2 – long pulse kicker for fast extraction – based on epoxy magnet technology (SLAC DR, ATF injection)

Plan

• Reduce required kick power – 4x TDR power(?)– 4 kickers ?– 10 mm diameter ?– DESY Behlke pulser ~basic unit is 10 　万 each … 20 or 30

needed.• Still expensive

– Vacuum chamber modifications will be more expensive– Stripline kicker

• Needs a design and consensus esp between SLAC/KEK/DESY

Kickoff meeting LBL 07.12.2004

• Caspers, Lambertson, Byrd…– More interesting ideas (based on p_bar cooling/ring

feedback exp.): • Slotted stripline – slow speed• Tapered stripline – wider band• Long, ceramic loaded line (?)

• This group should produce kicker design and cold test it

Proposed project

• Goal:– Proof of 5 ns principle before 06.2005– Extraction using 5ns full width 3MHz kicker by

01.2007 • KEK/DESY/SLAC/LLNL – pulser tests at KEK using

existing stripline• LBL – low beam-impedance kicker• KEK/SLAC – ATF modifications and design

Starting Parameters

Length (m)

Kick Angle (mr)

B field (kG)

dx at kicker exit (mm)

dx at Q6 entrance

dx at septum entrance

theta at septum entrance (- mr)

Energy = 1.3 GeV for all

TDR kicker 10 0.6 0.01 3 50 mm apertureATF present kicker, present layout 0.5 5 0.514 1.25 5.87 22.69 0.575

1.4 m kicker to get same incoming offset at septum 1.4 6.437 0.23268 4.58 4.58 22.69 1.299

1.4 m kicker fills the entire space between the kicker and Q6

2.9m, shift Q6 down 1.09, 5xs TDR B, start just after Q5 2.9 2.819 0.05 4.087 4.087 7.431 3.262 10 mm aperture2.9m, shift Q6 down 1.09, needed B 2.9 8.625 0.15267 12.479 22.69 7.494 large angleneeded Length to get 22.69 at .05 5.07 4.93 0.05 12.503 22.69 5.716 (Q6 still closer to Q7)3.4m (bh1rc|qm5r) 3.4 3.333 0.05 5.715 11.33 3.4493.4 needed B 3.4 6.675 0.100137 11.445 22.69 6.9071.4m 1.4 1.383 0.05 0.984 4.876 0.2641.4m, 1mm offset incoming 1.4 1.383 0.05 1.984 7.07 0.0992.9m 2.9 2.819 0.05 4.087 8.488 2.8032.9m w 1mm offs 2.9 2.819 0.05 5.057 9.953 2.9553.4m 3.4 3.305 0.05 5.618 11.162 3.4123.4m w 1mm 3.4 3.305 0.05 6.618 12.626 3.564