Beams of metallic ion species can be produced by the ECR (electron cyclotron resonance) ion source and by the MEVVA (metal vapor vacuum arc) ion source. Although the ECR source is fundamentally a gaseous ion source, metal ion beams can be produced by introducing metallic feed material into the plasma discharge using a number of techniques. The ion charge states can be very high, which is a significant advantage to most applications. The MEVVA ion source, on the other hand, is specifically a metal ion source. It has produced metallic ion beams from virtually all the solid metallic elements at a current of typically hundreds of milliamperes; the ions produced are in general multiply ionized, but not as highly stripped as those generated in the ECR source. Although the MEVVA source at present operates in a pulsed mode with a low duty cycle (less than or equal to 1%), work is in progress to increase the duty cycle significantly. In this paper the operation and performance of the LBL ECR and MEVVA ion sources, with respect to metal ion generation, are described.

We discuss an improvement to the algorithm developed by Yu for modelling rf cavities in klystrons using the port approximation. In this method, the cavity is simulated by imposing an rf voltage as a boundary condition across the outer wall. The voltage and phase are chosen to be consistent with the cavity impedence and with the rf current induced by the electron beam. In the original method, each cavity was calculated successively using either linear theory or an iterative method to achieve a self-consistent voltage. The new method relaxes the voltage and phase of several cavities simultaneously during the simulation. The time dependence of the voltages are calculated from a relaxation equation. The new algorithm reduces the total computation time by about a factor of five for a complete klystron.

We have measured the lifetime of an ensemble of particles containing b quarks, tagged with a high p/sub T/ lepton from their semileptonic decay. Using a method which estimates the production point of each particle in the beam ellipse, we measured a lifetime of 0.98 +- 0.12 +- 0.13 psec. We have also studied methods of partially reconstructing B mesons decaying into D/sup/star//minus// mesons plus charged leptons or mesons. We have searched the Mark II PEP data samples and find five candidates for B/sup 0/ decay. Four of these B/sup 0/ candidates form good vertices, and their measured proper lifetimes are presented. 18 refs.

The miscellaneous components of an accelerator may contribute a substantial or even dominant part of the interaction between beam and surroundings. We have estimated the beam impedances of a few of these components. When needed, we have added our own conceptions to the descriptions available at the Workshop on the RHIC Performance in order to make definite the calculations of impedance. These assumed parameters, while not unique, hopefully illustrate feasible and typical designs. 8 refs., 4 figs., 2 tabs.

Subsequent to an extensive smoothing of the vacuum chamber a comprehensive study of the SPEAR impedance was undertaken. Bunch length, synchrotron quadrupole mode frequency, and parasitic mode loss were measured as functions of beam current. The results showed that, although the gross longitudinal impedance had indeed been reduced, the 'capacitive' component had also decreased relative to the 'inductive'--to the extent that previously compensated potential well distortion now induced bunch lengthening at low currents, and the turbulent threshold had actually been lowered. A specially designed multi-cell disc-loaded 'capacitor' cavity was shown to be capable of removing this effect by restoring the original compensation. A model of the new SPEAR impedance is also obtained. 7 refs., 6 figs.

In this paper we present the results of measurements of bunch length and bunch shape as a function of current in the SLC e/sup /minus//damping ring. After extraction, the SLC bunch is compressed by means of an RF compressor and a subsequent high dispersion section. By inserting a video screen at a point of large dispersion and by using the correlation between bunch length and energy spread induced by the compressor, we have measured not only the bunch length but also the longitudinal charge distribution of the bunch in the damping ring as a function of beam intensity. At 3 /times/ 10/sup 10/ particles per bunch with a peak ring RF voltage of 800 KV, the FWHM of the bunch length in the ring doubles over the nominal value. To measure the energy spread of the bunch in the damping ring, the optics of the extraction lines was modified to produce a large dispersion but small horizontal ..beta.. function at the video screen. At 3 /times/ 10/sup 10/ particles per bunch, the relative energy spread in the rings is increased by about 30%. Finally, these data are compared with calculations of bunch lengthening in the SLC damping rings. 8 refs., …

A high level of current dependent bunch lengthening has been observed in the north damping ring of the Stanford Linear Collider (SLC), indicating that the ring's impedance is very inductive. This level of bunch lengthening will limit the performance of the SLC. In order to study the problem of bunch lengthening in the damping ring and the possibility of reducing their inductance we compute, in this report, the longitudinal impedance of the damping ring vacuum chamber. More specifically we find the response function of the ring to a short gaussian bunch. This function will later be used as a driving term in the longitudinal equation of motion. We also identify the important inductive elements of the vacuum chamber and estimate their contribution to the total ring inductance. This information will be useful in assessing the effect of vacuum chamber modifications. 7 refs. , 8 figs., 1 tab.

The URMEL code was used to calculate the frequencies, quality factors, and shunt impedances of the lowest modes of the proposed RHIC accelerating cavity. These values can be used as input for the calculation of the longitudinal and transverse coupled-bunch instabilities. The cavity dimensions were taken from the RHIC conceptual design report.

The Savannah River Plant and Laboratory employ more than 16,000 people. When the separate Publications Divisions of the Plant and Laboratory were combined it was determined that a single source of information for using terms was needed, and that the source would take the form of a word list. The Word List was issued to more than 5000 employees onsite. In addition, the Word List is being added to the site computer network as a reference document and as an online spelling checker where more than 2000 employees will have access to it through their personal computers.

We have considered high tune'' electron storage rings as a possible source of low emittance beams. The parameters of such rings are studied in the limit where the emittance is determined by intrabeam scattering. Rings with either superconducting or conventional magnets are considered. The object is to maximize the ratio of electrons/bunch to invariant emittance while maintaining a certain fixed intensity. We have also calculated the dynamic aperture for one ring of this type.

Excitation of large amplitude coherent dipole bunch oscillations by beam induced voltages in spurious narrow resonances are simulated using a longitudinal phase-space tracking code (ESME). Simulation of the developing instability in a high intensity proton beam driven by a spurious parasitic resonance of the rf cavities allows one to estimate the final longitudinal emittance of the beam at the end of the cycle, which puts serious limitations on the machine performance. The growth of the coupled bunch modes is significantly enhanced if a gap of missing bunches is present, which is an inherent feature of the high intensity proton machines. A strong transient excitation of the parasitic resonance by the Fourier components of the beam spectrum resulting from the presence of the gap is suggested as a possible mechanism of this enhancement. 10 refs., 4 figs., 1 tab.

This paper presents a characterization of the Alcator C Scrape-Off Layer (SOL) plasma during ICRF hydrogen-minority fast wave heating experiments. The SOL plasma parameters were measured using a multifunctional probe, JANUS, which is capable of simultaneously measuring the ion and electron parameters both parallel and antiparallel with respect to the toroidal magnetic field. The probe data indicate, at low value of injected rf power, there is direct edge heating and density increases at radii greater than that of the antenna Faraday shield. Increasing the injected rf power spreads both the temperature and density increases throughout the edge region, flattening the radial profiles. Varying the position of the resonance layer in the main plasma does not significantly change the effect of ICRF on the SOL parameters. Given this single spatial point characterization of the SOL, a crude estimate of power flow into and through the edge plasma indicate that /approximately/20% of the ICRF power launched from the antenna is absorbed /und directly/ in the SOL plasma. Additional observation of the impurity source rates confirms the conclusions of an earlier paper, which attributed increasing central densities of high-Z impurities to the increase in physical sputtering rate at both the ICRF antenna's Faraday …

In this paper we describe the early work carried out at LBL on the consequences of installing insertion devices (wigglers and undulators) on the beam dynamics of the ALS. This included analytical and tracking studies, and led to an insight to the reasons behind the predicted reduction in dynamic aperture. For completeness, a description of the unperturbed storage ring characteristics are also given. 3 refs., 16 figs., 2 tabs.

Computer simulation of electron and ion sources is made by using a class of computer codes known as gun design programs. In this paper, we shall first list most of the necessary and some optional capabilities of such programs. Then we will briefly note specific codes and/or authors of codes with attention to specialized applications if any. There may be many more such programs in use than are treated here; we are only trying to cover a range of examples, not perform a comprehensive survey.

The effects of intrabeam scattering on the beam dimensions and energy spread of a 100 GeV/amu gold beam are estimated. After 10 hours, growth of the transverse emittance is about a factor of three, with a similar growth in momentum spread. These findings are in agreement with earlier results of Parzen. Sensitivity of the results to the initial beam conditions is explored. In addition, calculations have been carried out for the case of high frequency (214 MHz) RF system. In this case the growth is more severe, giving a fivefold increase in transverse emittance. To ensure that the momentum spread after 10 hours does not exceed the RF momentum acceptance, a voltage in excess of 32 MV would be needed. 5 refs., 4 figs., 3 tabs.

The constraints on the universal energy density and cosmological constant from cosmochronological ages and the Hubble age are reviewed. Observational evidence for the galactic chemical evolution of the heavy-element chronometers is described in the context of numerical models. The viability of the recently discovered Th/Nd stellar chronometer is discussed, along with the suggestion that high r-process abundances in metal-poor stars may have resulted from a primordial r-process, as may be required by some inhomogeneous cosmologies.

A key feature of the high T/sub c/ oxides is a very small value of the Fermi energy. This feature leads to peculiar thermodynamic and transport properties in the normal and superconductive state. 24 refs., 1 fig.

An experimental cabling machine has been constructed and used to investigate the fabrication of a variety of superconducting cables. These include the 23-strand and 30-strand NbTi alloy cables for the Superconducting Supercollider (SSC) and a number of experimental cables. The experimental cables include 24-strands and 36-strands as well as two-level cables with a 6 or 7-strand first level and 23 or 30-strand second level. These results were used to aid in selecting the optimum cable for the SSC dipole and quadrupole magnets. As a result of these studies, cable can now be fabricated to exacting mechanical tolerances (+/- .006 mm) and with low critical current degradation (2-5%). In addition, tooling design studies have been performed and a Prototype SSC Production Cabling Machine has been designed. The results of the cable optimization studies and the tooling design studies will be discussed. SSC cable production experience on the experimental cabling machine and the production cabling machine will be reported.

A new software trigger scheme has been developed to augment and enhance the existing charged and neutral triggers by providing sensitivity to new event topologies and some level of control over accelerator-induced backgrounds. Historically, the Mark II existed with two primary trigger components: a charged track finder based upon the central and vertex drift chambers and the time-of-flight counters; and an electromagnetic trigger based upon the total energy deposited in each of ten calorimeter modules. The trigger component of the new system is based upon the Mark II electromagnetic calorimetry but with significantly increased granularity and the inherent flexibility of software. Trigger processing also benefits from the relatively long period of time (up to 8.3 ms) between SLC beam crossings. The production of long-lived neutral particles provides an example of an event topology which would not have triggered in the old system. By decaying beyond the first few drift chamber layers, such particles avoid the charged particle trigger, yet could produce clear signals in the calorimeters. Another example is the class of events containing a single photon as the visible particle such as occur in the reaction e{sup +}e{sup -} {yields} Z{sup 0}{gamma} {yields} {nu}{nu}{gamma}. Sensitivity to this reaction is …

The reaction e/sup +/e/sup -//yields/e/sup +/e/sup -//gamma/sup *//gamma/sup *///yields/(e/sup +/e/sup -/)/eta/, with subsequent decay of the /eta/ into two photons, has been observed with the ASP detector at the PEP e/sup +/e/sup -/ storage ring at /radical/ s=29 GeV. A measurement of the radiative width of the /eta/ yields the preliminary result /Gamma/(/eta//yields//gamma//gamma/) = .489 /+-/ .009 /+-/ .055 keV. Evidence for the production of the /eta/' with decay into two photons has also been observed.

Modeling analyses of preliminary experimental data obtained from the High Energy Laser (HEL) beam propagation tests (HELSMK-I) through tactically significant smokes are presented for the case of Fog-oil (FO). Thermal imager data together with transmission measurements and other experimental evidence are used to reconstruct and model the interaction physics of the HEL beam with FO. An earlier theoretical model by Wallace (1983) predicted that the high energy beam would vaporize large (>10..mu..m) FO droplets, while the smaller droplets primarily conduct their energy to the ambient air, thereby enhancing thermal blooming in air. This behavior is categorized as an anomaly for the interaction of a HEL beam with aerosols because complete vaporization would normally have been expected. The HELSMK-I test together with computational results from our nonlinear beam propagation codes confirmed this prediction. Fog-oil can thus be classified as an effective smoke shield against a HEL threat in open air at infra-red wavelengths, at flux levels of a few tens of Kilowattscm/sup 2/. These results also validated our computer models which show that a punch-through effect is prevented in FO due to its enhanced blooming characteristics. 5 refs., 7 figs.

Argonne National Laboratory (ANL) has performed a number of examinations to determine the microstructure and micro-chemistry of samples of debris from the TMI-2 reactor. These examinations have been a small part of the overall effort to gain an understanding of the TMI-2 accident. As a result of these overall efforts, a general scenario of the response of the core components has been established. In this paper we will describe the microstructure and micro-chemistry of debris from the lower plenum of the reactor and relate these data to a segment of the general scenario dealing with the relocation of this material. The primary tools used at ANL for the examination of material from the TMI-2 core were optical microscopy, scanning electron microscopy and Energy Dispersive X-Ray Spectroscopy, and Scanning Auger Spectroscopy. In some cases these techniques were augmented by the use of gamma spectroscopy, autoradiography, and X-ray diffraction analysis.

The history of PET research clearly demonstrates that it is advances in chemistry coupled with a detailed examination of the biochemistry of new radiotracers which has allowed the PET method to be applied to new areas of biology and medicine. Radiotracers whose regional distribution reflects glucose metabolism, neutrotransmitter activity and enzyme activity have all required the development of rapid synthetic methods for the radiotracers themselves and the characterization of their biochemical behavior. This article traces some of the advances in the production of labeled precursors and in radiotracer synthesis and evaluation which have shaped the rapidly expanding application of PET to problems in the neurosciences, in cardiology and in oncology. 54 refs.

Collision-induced infrared spectroscopy may be used to measure the composition of a liquid or solid deuterium-tritium (D-T) mixture. For T/sub 2/, DT and D/sub 2/, respectively, we measure the areas under the absorption peaks in the regions 76.75 to 80.19, 85.29 to 88.74, and 92.79 to 96.23 THz (2560-2675, 2845-2960, and 3095-3210 cm/sup /minus/1/). These areas are multiplied, respectively, by these isotopic sensitivities derived from quantum calculations: 1.000, 0.891, and 0.811. The resulting numbers are proportional to the molar composition. Nearly equimolar D-T samples show good agreement between mass and infrared spectroscopy. The large DT peak in enriched molecular DT overemphasizes D/sub 2/ in the infrared analysis, but these results may be corrected with the room-temperature, mass-spectroscopic D-to-T ratio. 7 refs., 2 figs., 2 tabs.