[en] The transfer of SF₆ insulating gas from the 25 MV accelerator pressure vessel (volume = 80,000 ft³) into liquid storage tanks (volume = 6,000 ft³) is accomplished by means of two three-stage piston compressors operating in parallel. Gas from the first and second compression stages is passed through heat exchangers prior to injection into subsequent stages while gas from the third stage is cooled and/or liquified by a third exchanger/condenser. Tabulated thermodynamic data were used in calculating the SF₆ transfer rate, stage compression ratios and heat transfer rates as a function of the fraction of the total inventory of SF₆ (270,000 lbs) which has been transferred. The SF₆ temperature, pressure and liquid fraction are also calculated at various points throughout the system. Operating parameters and procedures are recommended which should eliminate the possibility that liquid SF₆ is injected into a compressor cylinder and prevent the generation of excessive pressure in the storage tanks

[en] The double-drift beam bunching system consists of two bunchers that are separated in space, independently driven but phase-locked together. The second buncher to be encountered by the beam is driven at twice the frequency of the first. This system offers an attractive alternative to conventional one- and two-frequency systems since its bunching efficiency is about twice that for a single frequency system and about 25% larger than that for a two-frequency system in which both harmonics are imposed on the same electrode. The independence of the two bunchers provides for greater ease in the adjustment and stabilization of the rf amplitudes and phase to the accuracy of +-1% and +-0.5⁰ that is required. A double-drift system, designed to operate as 4.5 to 14 MHz, has been installed on the ORNL EN-tandem and evaluated using ¹⁶O, ³²S, ⁵⁸Ni, and ⁶³Cu ion beams. Performance was in close agreement with predictions; about 60% of the dc beam was bunched into a phase angle of 6⁰ of the fundamental frequency. A brief discussion of the principles of operation, predicted performance and practical design considerations are given. Results of a theoretical study of the dynamic focusing effects and energy-modulation imperfections of ungridded klystron bunchers are presented as approximate formulas

No abstract available

[en] A high level language, CHIL, has been developed for use in processing event-by-event experimental data at the Holifield Heavy Ion Research Facility (HHIRF) using PERKIN-ELMER 3230 computers. CHIL has been fully integrated into all software which supports on-line and off-line histogramming and off-line preprocessing. CHIL supports simple gates, free-form-gates (2-D regions of arbitrary shape), condition test and branch statements, bit-tests, loops, calls to up to three user supplied subroutines and histogram generating statements. Any combination of 1, 2, 3 or 4-D histograms (32 megachannels max) may be recorded at 16 or 32 bits/channel. User routines may intercept the data being processed and modify it as desired. The CPU-intensive part of the processing utilizes microcoded routines which enhance performance by about a factor of two

No abstract available

[en] Results of high spin studies on ⁴⁴Ca as a result of 30-40 MeV ¹⁶O bombardment of ²⁸Si are reported. The observed levels compare well with thermal neutron capture results. (2 figures) (U.S.)

[en] The mean lifetimes, obtained from a least-squares fit of the calculated line shapes to the experimental data for the 3^- → 2⁺ and 3^- → 4⁺ transitions, of the 3^- states in ^156158160Gd, and ¹⁶⁰Dy were found to be (0.11 +- 0.03), (0.78 +- 0.21), (0.074 +- 0.020), and (0.32 +- 0.09) ps, respectively. Experimental results for the reduced transition probabilities, B(E1, J/sub i/ → J/sub f/), deduced from the mean lifetimes of the 3^- states are tabulated along with B(E1) values for E1 transitions from the decay of two K,J/sup π/ = 0,2⁺ states feeding the K = 0 and 1 octupole bands in ¹⁵⁸Gd. 1 table

[en] The lifetime of the 3.830 MeV state in ⁴¹Ca has been determined from the measured delayed coincidence time distribution between neutrons and gamma rays from the reaction ²⁸Si(¹⁶O 2pnγ)⁴¹Ca at 40 MeV. The result is 4.16 +- 0.20 nsec. (1 figure) (U.S.)

[en] Direct E2 and E3 Coulomb excitation of 2⁺ and 3^- states with 13.5-MeV ⁴He ions on isotopically enriched targets of ^156-160Gd and ^160-164Dy was measured by means of γ-ray spectroscopy. Several 2⁺ states and ^3- octupole vibrational states were identified in each nucleus. The B(Elambda, 0 → J = lambda) is obtained for excitation of each state, and information is given on the reduced transition probabilities for the different decay modes of these states. The experimental results are compared with theoretical predictions of nuclear models describing these states. 2 tables

[en] Results from gamma-ray spectroscopy with 13.5-MeV ⁴He ions on isotopically enriched targets of ¹⁵⁶Gd, ¹⁵⁸Gd, ¹⁶⁰Gd, ¹⁶⁰Dy, ¹⁶²Dy, and ¹⁶⁴Dy are presented. The experimental results for the reduced transition probabilities, B(Elambda, 0 → J = lambda), are tabulated along with K, J/sup π/ assignments. The experimental B(E2, 0 → 2) for ^156-160Gd are compared with recent theoretical calculations based on a dynamic deformation theory combined with the pairing-plus-quadrupole model. In the case of K = 2 γ-vibrational state, the B(E2) values are reproduced reasonably well by the predictions. However, the B(E2) values for β-vibrational states are not reproduced satisfactorily. 1 table