Measurement of the main ring longitudinal impedance by debunching

Technical Report · Sat Feb 01 00:00:00 EST 1986

DOI:https://doi.org/10.2172/6017422· OSTI ID:6017422

Ng, K Y

An experiment was carried out to observe microwave signals of the bunched beam in the Fermilab Main Ring. The purpose of this paper is to analyze the experiment and attempt a computation of the longitudinal impedance per unit harmonic Z/n of the Main Ring. The result of the analysis indicates Z/n = 8.6 ..cap omega.. if the driving impedance is a broad band at f/sub MW/ = 1.646 GHz. However, if the driving impedance is a high-Q resonance at 1.646 GHz with RMS width less than approx.0.13 GHz (or Q approx. 50), Z/sub sh//Q of the resonance is 5.2 k..cap omega... We demonstrate that the proton bunches are of Gaussian shape. The time at which the microwave amplitude starts to grow is determined. We find that this occurs when two adjacent bunches overlap each other. A stability criterion is derived for the overlapped bunches. Then Z/n and Z/sub sh//Q are computed. The source of the driving impedance is traced.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• DOE Contract Number: AC02-76CH03000
• OSTI ID: 6017422
• Report Number(s): FNAL-TM-1389; ON: DE86009135
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
FERMILAB ACCELERATOR
BEAM BUNCHING
IMPEDANCE
HARMONICS
MICROWAVE RADIATION
PROTON BEAMS
ACCELERATORS
BEAM DYNAMICS
BEAMS
CYCLIC ACCELERATORS
ELECTROMAGNETIC RADIATION
NUCLEON BEAMS
OSCILLATIONS
PARTICLE BEAMS
RADIATIONS
SYNCHROTRONS
430200* - Particle Accelerators- Beam Dynamics
Field Calculations
& Ion Optics