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.
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.
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.
36506128
Experimental Test of a New Antiproton Acceleration Scheme in the Fermilab Main Injector
In an effort to provide higher intensity and lower emittance antiproton beam to the Tevatron collider for high luminosity operation, a new Main Injector (MI) antiproton acceleration scheme has been developed [1-4]. In this scheme, beam is accelerated from 8 to 27 GeV using the 2.5 MHz rf system and from 27 to 150 GeV using the 53 MHz rf system. This paper reports the experimental results of beam study. Simulation results are reported in a different PAC’ 05 paper [5]. Experiments are conducted with proton beam from the Booster. Acceleration efficiency, emittance growth and beam harmonic transfer between 2.5 MHz (h=28) and 53 MHz (h=588) buckets have been studied. Beam study shows that one can achieve an overall acceleration efficiency of about 100%, longitudinal emittance growth less than 20% and negligible transverse emittance growth.
109094861
Modification of Linac 7651 driver to operate at 425 MHz
119475729
The compression modulus of the nucleon and delta
Abstract The compressibility of the nucleon and delta are calculated in a variety of models, and its relevance to the compression of nuclear matter is discussed. The limiting temperature of a constituent phase is also examined.
15609214
Possible evidence of surface vibration of strange stars from stellar observations
Emission lines in the eV and keV range by certain stellar candidates from their recent analysis invoke the question of their possible origin. The stars under consideration are 4U 0614+091 (0.65, 0.86 and 1.31 keV), 2S 0918-549 (0.8 keV with width 55 eV), 4U 1543-624 (0.7 keV), 4U 1850 -087 (0.7 keV) and 4U 1820-30 (0.6 and 0.9 keV) and also the 0.6-keV excess emission in RX J1 70930.2-263927. Recently, it has been suggested that the resonance absorption at ∼ 0.7, 1.4, 2.1 and 2.8 keV in 1E1207-5209 and 0.35, 0.7 and 1.4 keV in RX J1856.5-3754 are due to harmonic surface vibrations in strange stars. We propose that these harmonic vibrations may also be responsible for emission lines in the above mentioned compact stellar candidates.