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Title: Design of the 0.5 - 1 GHz Planar Recycler Pickup and Kicker Antennas

The stochastic cooling system in the Recycler ring at Fermilab required the addition of a 0.5-1 GHz cooling system. This requirement dictated the design of a new antenna for this band of the system. The design problem is defined, method of design is illustrated, and the measurement data are reported. The Recycler is a storage ring comprised of mostly permanent magnets located in the tunnel of the Main Injector at Fermilab. The goal for the construction of the Recycler is to collect and store unused antiprotons from collisions in the Tevatron for use in future collisions in the Tevatron. It will both stochastically and electron cool these unused antiprotons before another collision experiment is possible in the Tevatron. By reusing the antiprotons the luminosity of the experiment can be increased faster. The Recycler will use three bands for its stochastic cooling system. It will reuse the existing designs from the Antiproton Source for the 1-2 GHz and 2-4 GHz systems, and it requires a new design for an additional lower frequency band for the 0.5-1 GHz system. Since the existing designs were fabricated using a microstrip topology it was desired that the new design use a similar topology so thatmore » the vacuum tank designs and supporting hardware be identical for all three bands. A primary difference between the design of the pickups/kickers of the Antiproton Source and the Recycler is a different aperture in the machine itself. The Recycler has a bigger aperture and consequently reusing the designs for the existing Antiproton Source pickups/kickers is not electrically optimal but is cost efficient. Measurements will be shown later in this paper for the design of the 0.5-1 GHz system showing the effect of the aperture on the antenna performance. A mockup of the Recycler tank was manufactured for designing and testing the 0.5-1 GHz pickups/kickers. The design procedure was an iterative process and required both a constant dialogue and also a strong relationship with a board house for the manufacture of each iterative step. It also required extensive use of time domain reflectometers (TDRs) and vector network analyzers (NWAs). The TDR was used for impedance matching and for a rough measurement of the center frequency of the antenna. The testing process also used the theory of stretched wire measurements (SWM) for finding the exact center frequency of the pickups/kickers as well as the beam coupling to the antenna.« less
Authors:
;
Publication Date:
OSTI Identifier:
984607
Report Number(s):
FERMILAB-PBAR-NOTE-627
TRN: US201016%%1520
DOE Contract Number:
AC02-07CH11359
Resource Type:
Technical Report
Research Org:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ANTENNAS; ANTIPROTON SOURCES; ANTIPROTONS; APERTURES; CONSTRUCTION; COOLING SYSTEMS; DESIGN; ELECTRONS; FERMILAB; FERMILAB TEVATRON; IMPEDANCE; LUMINOSITY; MOCKUP; PERMANENT MAGNETS; STOCHASTIC COOLING; STORAGE RINGS; TANKS; TESTING; TOPOLOGY; VECTORS Accelerators