110039324
Improving the linearity of ferrite loaded cavities using feedback
A simple beam loading compensation system was installed for the Fermilab Main Injector Coalescing Cavities. This paper describes the design and implementation of the feedback system. These modifications improved the linear dynamic range of operation of the ferrite loaded cavity.
111241112
Linearization of the Fermilab recycler high level RF
In studying the recycler high level RF, it was found that at 89 kHz, the lowest frequency required by the system, some nonlinearities in magnitude and phase were discovered. The visible evidence of this was that beam injected in a barrier bucket had a definite slope at the top. Using a network analyzer, the S-parameter S/sub 21/ was realized for the overall system and from mathematical modeling a second order numerator and denominator transfer function was found. The inverse of this transfer function gives our linearization transfer function. The linearization transfer function was realized in hardware by summing a high pass, band pass and low pass filter together. The resulting magnitude and phase plots, along with actual beam response will be shown.
73632693
Antiproton acceleration in the Fermilab Main Injector using 2.5 MHz (H=28) and 53 MHz (H=588) RF systems
During the Run II era at Fermilab, the Recycler stores antiprotons at 8 GeV and the Main Injector accelerates the antiprotons and the protons from 8 GeV to 150 GeV for Tevatron injection. The Recycler injects antiprotons to the Main Injector in 2.5 MHz rf buckets. This report presents an acceleration scheme for the antiprotons that involves a slow ramp with initial 2.5 MHz acceleration and subsequent fast acceleration with 53 MHz rf system. Beam acceleration and rf manipulation with space charge and beam loading effects are simulated using the longitudinal simulation code ESME. Simulation suggests that one can expect about 15% emittance growth for the entire acceleration cycle with beam loading compensations. Preliminary experimental results with proton beam will also be presented.
109094861
Modification of Linac 7651 driver to operate at 425 MHz
6190198
Narrowband beam loading compensation in the Fermilab Main Injector accelerating cavities
A narrowband beam loading compensation system was installed for the Main Injector accelerating cavities. This feedback operates solely on the fundamental resonant mode of the cavity. This paper describes modifications to the high level radiofrequency system required to make the system operational. These modifications decreased the effect of steady-state beam loading by a factor of 10 and improved the reliability of paraphasing for coalescing.
122069162
Design and operation of PET radio frequency quadrupoles
The PET isotope production accelerator built by a collaboration of BRF, FNAL, SAIC, and UW consists of four RFQ's to accelerate /sup 3/He/sup 2+/ ions to 10.5 MeV for production of radioactive /sup 18/F, /sup 11/C, /sup 15/O and /sup 13/N isotopes. The design, tuning, and operational results are presented.
121946450
The breathing mode of the skyrmion: a Hamiltonian with co-ordinate-dependent inertia
SummaryA contact transformation of the Hamiltonian enables one to tackle the problem of co-ordinate-dependent inertia. We use this method to solve for the breathing mode excitation of the recently revived Skyrme model for the nucleon.RiassuntoUna trasformazione di contatto dell’hamiltoniana permette di affrontare il problema dell’inerzia dipendente dalle coordinate. Si usa questo metodo per risolvere l’eccitazione di modo che respira del modello di Skyrme recentemente rivisitato per il nucleone.РезюмеКонтактное преобразование Гамильтониана розволяет рассмотреть проблему инерции, зависящей от координат. Мы используем этот подход для исследования возбуждения моды «дыхания» для нуклона в рамках модели скирмиона.
121634326
Baryon spectra in the interacting boson model
Abstract We propose the interacting boson model (IBM) description of the excitation spectra built on N(1440), Δ (1600) and Λ (1600). The adopted SU(3) symmetry suggests that the positive parity excited states of the baryons (N, Δ and Λ ) are realized as deformed objects.