R. Corsini, 1 Feb 2004

CTF3 BEAM DYNAMICS ISSUES

R. Corsini

Beam dynamics meeting

R. Corsini, 1 Feb 2004

locations relevant effects issues/studies codes (presently used)

Injector/1st chicane space charge, CSR ? matching, oscillations, coupling ? PARMELA-MATHCAD models

Linac transverse wake-fields linear optics, steering, (in)stability MAD (with acceleration)

Stretcher/TL1 CSR linear optics, dispersion, emittance growth ? ?

DL & Combiner Ring Deflector wake-fields linear optics, transverse stability PLACET, INFN code (D. Alesini)

CLEX

Drive Beam Accelerator

Delay Loop

Stretcher

Transfer LineTo CR (TL1)

Combiner Ring

CTF3 Layout

CTF3 - Transverse beam dynamics issues

R. Corsini, 1 Feb 2004

chicane

linac

• Quad scans (I) in girder 7

Quad scans (I)

150 100 50 00

0.5

1

1.5

207 october - quad scan - Vertical

Current in QFF420 (A)

Bea

m r

ms

size

(m

m)

50 100 150 2000

0.5

1

1.5

207 october - quad scan - Horizontal

Current in QFF420 (A)

Bea

m r

ms

size

(m

m)

Measurement (II)

Fit (II)Reconstructed with

MAD from (I)

• Re-matching to regular triplet lattice (relaxed optics, = 4m)

• Beam transport 100% (3.5 A - nominal current)

Setting-up procedure:

Quad scans (II)

• Quad scans (II) in end-of-linac screen

Measured rms normalized emittance:

X = 135 140 mm mrad

Y = 130 200 mm mrad

Measured rms normalized emittance:

X = 135 140 mm mrad

Y = 130 200 mm mrad

CTF3 - linac modeling

R. Corsini, 1 Feb 2004

locations relevant effects issues/studies codes (presently used)

Injector/1st chicane space charge bunching, parasites bunches PARMELA-MATHCAD models

Linac Long. Wakes bunch length, energy spread analytical models

Stretcher/TL1 CSR bunch compression/lengthening ELEGANT (Frascati)

DL & Combiner Ring CSR, impedance longitudinal phase space evolution analytical models

CLEX

Drive Beam Accelerator

Delay Loop

Stretcher

Transfer LineTo CR (TL1)

Combiner Ring

CTF3 Layout

CTF3 - Longitudinal beam dynamics issues

R. Corsini, 1 Feb 2004

CTF3 - bunch length gymnastics

R. Corsini, 1 Feb 2004

R. Corsini, 1 Feb 2004

INFN/Frascati chicane

matching triplet

magnetic chicane RF deflector

bypass

Can be bypassed - Variable R56 - bunch length measurement with vertical RF deflector

Optics studies and measurements:

• Dispersion measurements (orbit difference)

• Bunch length measurements

matching triplet Spectrometer

(OTR screen)

OTR screen

BPIs

SR monitors

• Commissioning of INFN beam position monitors (BPI), synchrotron radiation monitors, new instrumentation section.

instrumentationsection

R. Corsini, 1 Feb 2004

Dispersion & bunch length measurements

Dispersion measurement:

• magnet current scaling 1%• orbit difference

Bunch length measurement:

• Vertical deflection in RFD

• Measure vertical beam size in OTR (with & without RF)

• Change chicane optics – R56

measured

simul.gaussian

preliminary

simul.unif.

R. Corsini, 1 Feb 2004

R. Corsini, 1 Feb 2004