Nonlinear dynamics experiment in the Tevatron

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Mar 20, 1989 - mediate amplitudes cm finds the S-th order resonance island chain of. Fig. ... The existence of stable nonlinear resonmce islands was demon-.
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Fermi National Accelerator

Laboratory FERMILAB-Conf-89/85

Nonlinear

Dynamics

Experiment

in the TEVATRON

*

N. Merminga, D. Edwards, D. Finley, R. Gerig, N. Gelfand, M. Harrison, R. Johnson, and M. Syphers Fermi NationalAccelerator Laboratory P.O. Box 500, Batavia, Illinois 60510

R. Meller, R. Siemann, and R. Tahnan Newman Laboratory of Nuclear Studies Cornell University Ithaca, New York 14853

P. Morton Stanford Linear Accelerator Center Stanford, California 94305

A. Chao, T. Chen, D. Johnson, S. Pegs, J. Peterson, C. Saltmarsh, and L. Schachinger SSCCentralDesignGroup c/o Lawrence Berkeley Laboratory 90/4040 Berkeley, California94720

March 1989

* Presentedby N. Metinga e*

waled

at tbe 1989 IEEE Particle Accelerator Conference,Chicago, Illinois, March 20-23, 1989.

by Universities

Research

Assoclailon,

Inc., under contract

with the United Slates Department

of Energy

NONLINEAR N.Merminga,

DYNAMICS

D. Edwards, D. Finley,

Fermi National

EXPERIMENT FL. &rig,

Awelcmtor

R. M&r,

N. Gelfand,

IN THE TEVATRON M. Harrison,

Labomtory,‘Botavia,

R. Siemann,

FL. Johnson,

M. Syphers

IL 60510

R. Talman

Nemnon Laboratory of Nuclear Studies, Cornell University,

Ithaca, NY 14853 U.S.A.

P. Morton

Stanford Linear Aecelemtor Center, Stanford, CA 94305 U.S.A. A. Chao,

T. Chen, D. Johnson,

S. Peggs, J. Peterson,

C. Saltmarsh,

L. Schachinger

SSC Central Design Croup, Berkeley, CA 947% U.S.A.

Abstract Results of the continuing analysis of the nonlinear dynamics experiment E778 are presented. Sixteen special sextupoles introduced nordinearities in the Tevatron. ‘Smear,’ which is one of the paremeten used to quantify the degree of nordinearity, was extracted from the data and compared with calculation. Injection efficiency in the presence of nordinearitier was studied. Measurements of the dynamic aperture were performed. The final results in one degree of freedom of the smear, the injection efficiency and the dynamic aperture are presented. Particles captured on nonlinear resonance islands were di,ertly obaerved and measurements were performed. The capture efSciency was extracted from the data and compared with prediction. The inffuence of tune modulation on the stability of these islands was investigated. Plans for future measurements aye discussed.

Introduction

EfRciency/Dynamic

Aperture

The first purpose of ET78 WY to determine if smear is predictable from tracking calculations. The second purpose was to find the correlation between smear and accelerator performance measures such as injection efficiency and particle lifetime. Measurements of the dynamic aperture were performed and comparisons with track@ calculations were made. The final remdts in one degree offreedom of the smear, the variation of tune with amplitude, and the dynamic aperture are summarized in ‘Opc.strd by the Unirrrsitics u. s. Depvtment o‘Eo.r.J.

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