The Mirror Fusion Test Facility (MFTF-B) now under construction at Lawrence Livermore National Laboratory represents more than an order-of-magnitude step from earlier magnetic-mirror experiments toward a future mirror fusion reactor. In fact, when the device begins operating in 1986, the Lawson criteria of ntau = 10/sup 14/ cm/sup -3/.s will almost be achieved for D-T equivalent operation, thus signifying scientific breakeven. Major steps have been taken to develop MFTF-B technologies for tandem mirrors. Steady-state, high-field, superconducting magnets at reactor-revelant scales are used in the machine. The 30-s beam pulses, ECRH, and ICRH will also introduce steady-state technologies in those systems.

The present paper describes a verification of CONVEC2 for single-zone geometries by comparison with the results of two natural convection experiments performed in small-scale rectangular enclosures. These experiments were selected because of the high Rayleigh numbers obtained and the small heat loss through the insulated surfaces. Comparisons are presented for (1) heat transfer rates, (2) fluid temperature profiles, and (3) surface heat flux distributions.

The physics of deep inelastic heavy ion collisions is briefly reviewed in the light of the experimental capabilities offered by large Tandem Accelerators. Three aspects are selected for illustration. The first is the problem posed by the angular distributions. The role of quantal fluctuations (diffraction) and of dynamical fluctuations is discussed. The possibility of extracting angular momentum fluctuations from the angular distribution width is pointed out, as well as the way to compare such results with those obtained from gamma-ray multiplicities or angular distributions. The likely sources of angular momentum fluctuations are discussed. The second problem is that of energy dissipation and partition. The experimental evidence from thermal equilibrium is reviewed and experiments to test thermal equilibrium through the measurement of the variance in the energy distribution are suggested. The correlation between energy loss and the mass variance is reviewed in terms of the mass transfer mechanism. Possible ways to determine the mass of the transferred particle are illustrated. The third problem considered is the experimental lack of mass drift in the mass distributions vs Q-value when it is expected on the basis of potential energy considerations. This problem is associated with the fast fragment thermalization and explained in terms …

Progress in a two year study of a 1200 MWe commercial tandem mirror reactor (MARS - Mirror Advanced Reactor Study) has reached the point where major reactor system technologies are identified. New design features of the magnets, blankets, plug heating systems and direct converter are described. With the innovation of radial drift pumping to maintain low plug density, reactor recirculating power fraction is reduced to 20%. Dominance of radial ion and impurity losses into the halo permits gridless, circular direct converters to be dramatically reduced in size. Comparisons of MARS with the Starfire tokamak design are made.

The small apertures common in many RFQ linac designs lead to tuning difficulties, primarily because asymmetries in the quadrant fields can arise as a result of small non-uniformities in the vane-to-vane capacitances. Sensitivity to such capacitance or other tuning variation in the quadrants is greatly reduced by the introduction of pairs of vane-coupling rings that provide periodic electrical connections between diametrically opposite vanes. Results of measurements on a cold model RFQ structure with and without vane-coupling rings are presented. The number of rings required for field stabilization and the effect of rings on mode frequencies are discussed.

A cryogenically cooled liner has been installed within the Bevatron to achieve 10/sup -10/ torr vacuum. Features and performance of this liner are described including achieved pressures, residual gas composition, cryo heat loads, leak rates through moving and static seals, and cool-down and warm-up times.

A CMN thermometer has been calibrated by nuclear-orientation thermometry at low temperatures and He vapor-pressure thermometry at high temperatures. The calibration agrees well with the NBS temperature scale between 100 and 200 mK. Specific-heat data on /sup 3/He in the Fermi-liquid region obtained with this thermometer are in good agreement with recent measurements at Bell Laboratories. It is argued that discrepancies with other data can be understood on the basis of errors in the temperature scales on which they are based.

The Advanced Light Source (ALS) is a new synchrotron radiation source which has been proposed by Lawrence Berkeley Laboratory. The ALS will be a key component in a major new research facility, the National Center for Advanced Materials. The ALS will consist of an electron linear accelerator, a booster synchrotron, a 1.3-GeV electron storage ring, and a number of photon beam lines. Most or all photon beam lines will originate from wiggler and undulator magnets placed in the 12 long straight sections of the ALS. A very low electron beam emittance will provide photon beams of unsurpassed spectral brilliance from specially-designed undulators, and a high radiofrequency will produce very short pulse lengths.

We are investigating the RF properties of thin films of materials which are known to have low secondary emission coefficients, such as NbC, NbN and TiN. Preliminary measurements on the latter material have been performed by depositing a 15 nm film on parts of a doubly re-entrant Nb cavity designed to favor electron multipacting which, in the uncoated cavity, occurs copiously between the posts' tips. The measurements performed with TiN films sputtered onto Nb indicate that the RF current losses are increased by the presence of the films while the dielectric losses are negligible, within the measurement sensitivity of the system. The electron multipacting cannot be excited between the posts coated with the material tested.

A new heavy-ion accelerator facility for radiotherapy is being designed at the Lawrence Berkeley Laboratory. Performance requirements have been established. Ions from helium to argon can be accelerated to a maximum energy of 800 MeV/nucleon with intensities in the range 10/sup 8/ to 10/sup 9/ particles per second. The accelerator subsystems consist of a linac injector, a synchrotron, and a beam-delivery system. Specifications have been developed for many of the technical components, and some details of the technical design are presented.

The properties of various non-crystalline semiconductors are considered for use as position-sensitive detectors. Amorphous silicon and conducting plastic can be doped to form NP depletion regions similar to those in single crystal silicon, but without the limitation of single-crystal size. Chalcogenide glassy materials such as Te-Se-Ge compounds as well as some metallic oxides such as the Vanadium oxides have switching and memory properties. They could serve as x,y location identifying devices when triggered by amplified pulses from a parallel plate or multistep gas-filled detector stage in order to resolve the multitrack ambiguity for x,y readout schemes.

Liquid lithium-lead eutectic alloy (17 at % Li-83 at % Pb, referred to herein as Li-Pb) is currently being considered as a candidate breeding material for fusion reactors. Some important considerations in the design of a Li-Pb blanket are compatibility with the structure, tritium containment and recovery, and safety. Additional design complexities arise because of the high density of Li-Pb, the relatively high melting temperature (235/sup 0/C), and the high tritium over-pressure associated with this alloy. In this study, the Li-Pb eutectic was considered both as the breeder and as the coolant. Thermal hydraulic and stress analyses were conducted to assess the technical feasibility of using Li-Pb as the breeder and coolant based on DEMO reactor conditions. The results of the thermo-mechanical analyses showed that the elongated cylindrical blanket modules made from either HT-9 or vanadium alloy offer a viable first wall/blanket design concept.

Numerical models on several levels of complexity should be available to the emergency response planner. They are a basic tool but must be used in conjunction with both measurements and experience. When these tools are used in a complimentary fashion they greatly enhance the capability of the consequence manager to respond in an emergency situation. Because each accident or incident develops it's own characteristics and requirements the system must be capable of a flexible response. Interaction and feedback between model results from a suite of models and measurements (including airborne measurements) serve the emergency response planner's spectrum of needs, ranging from planning exercises and emergency precalculations to a real-time emergency response.

COBRA, in general, performs a thermal-hydraulic analysis of an actual pin bundle by subdividing the bundle cross-section into coolant subchannels, pin sectors, duct wall sectors. Its calculation includes heat convected axially upward through coolant mass flow, heat flow between pin sectors and adjoining subchannels, and heat and mass flow between coolant subchannels. COBRA-3M is a version of COBRA built for LMFBR applications, that includes a sophisticated thermal model of fuel pins and duct wall. COBRA-3M that can explicitly model a wider variety of pin bundle configurations than 3M would allow and includes significant improvements to its thermal modeling. COBRA-PI is currently being used for thermal-hydraulic analysis of hypothetical LMFBR accident transients in both power and flow. Pin bundles currently being analyzed explicitly range from 7 to 37 pins of axial lengths ranging from approx. 0.3-2.0 meters.

The emission of positrons from supernova ejecta is dicussed in terms of the galactic-center annihilation radiation. The positrons from the radioactive sequences /sup 56/Ni..-->../sup 56/Co..-->../sup 56/Fe are the most numerous source from supernova. Only type I supernova will allow a significant fraction to escape the expanding ejecta. For a neutron star model of a type I SN a fraction 4 x 10/sup -3/ of the escaped positron is enough to create the observed several year fluctuation of the annihilation radiation. The likelihood of this model is discussed in terms of other astrophysical evidence as well as the type I SN light curve.

The Heavy Ion Superconducting Spectrometer (HISS) facility and coils are briefly described while most of the paper discusses the support structures consisting of flanged doubly tapered stainless steel cylinders having a Z-shaped cross-section with average diameter of approximately 2.35 meters and height of approx. .49 meters. This member serves as a one piece coil support to resist gravitational, seismic, and magnetic forces with an approximate heat leak to helium of 59 watts per cylinder during operation of magnet at 4 degrees K. Maximum magnetic forces on each coil are over 11 meganewtons at 3T excitation. Magnetic forces attracting the coils to the core vary with excitation in direction as well as in magnitude. Radial magnetic forces produce stresses internal to the coil bobbin.

Tests have been performed on the breakdown behavior of a TM/sub 010/ mode, S-band niobium cavity at low temperatures. Unloaded Q's of 9 x 10/sup 7/ at 4.2 K and of 7 x 10/sup 9/ at 1.35 K were measured during several tests performed using pulses long enough for the cavity to reach steady state. The breakdown field at 1.35 K was increased from 15 to 20 MV/m by processing the cavity at room temperature using 1 MW, 2.5 ..mu..s pulses. The response of the cavity at 4.2 K to 1 MW, 2.5..mu..s pulses was also tested in several cool-downs. In these tests the cavity was heavily overcoupled to lower its time constant to a value of 0.80 times the RF pulse length of 2.5 ..mu..s. This condition maximizes the energy transfer from the klystron source to the cavity. Measurements made during these experiments clearly indicated that fields of about 50 MV/m were being reached in the cavity without breakdown.

The history and current status of SLAC's SDLC networks for distributed accelerator control systems are discussed. These local area networks have been used for instrumentation and control of the linear accelerator. Network topologies, protocols, physical links, and logical interconnections are discussed for specific applications in distributed data acquisition and control system, computer networks and accelerator operations.

An Electron Cyclotron Resonance (ECR) heavy-ion source is under construction at the LBL 88-Inch Cyclotron. This source will produce very-high-charge-state heavy ions, such as 0/sup 8 +/ and Ar/sup 12 +/, which will increase cyclotron energies by a factor of 2-4, up to A = 80. It is a two-stage source using room-temperature coils, a permanent-magnet sextupole, and a 6-9 GHz microwave system. Design features include adjustable first-to-second-stage plasma coupling, a variable second-stage mirror ratio, high-conductance radial pumping of the second stage, and a beam-diagnostic system. A remotely movable extraction electrode will optimize extraction efficiency. The project includes construction of a transport line and improvements to the cyclotron axial-injection system. The construction period is expected to be two years.

Many of the upper main-sequence stars pulsate in spheroidal nonradial modes. We know this to be true in numerous cases, as we have tabulated for the ..beta.. Cephei and delta Scuti variables in previous lectures. However, we cannot identify the actual mode for any star except for the low-order pressure p and f modes of our sun. It remains a great challenge to clearly state what really is occurring, in the process we learn more about how stars evolve and pulsate.

The nuclear performance of a candidate fission-suppressed, U233-producing blanket is assessed. It is predicted to have a breeding ratio (fusile + fissile) of 1.68 and produce U233 at a rate of 8030 kg/year from 3140 MW of DT fusion and a blanket coverage of 96%. Blanket energy multiplication is estimated to vary between 1.3 and 2.0 as the U233/Th232 ratio varies between 0 and 0.5%. Heterogeneous effects in the blanket's pebble-bed configuration were found to be important and more detailed analysis is needed to more accurately predict Li6 content required and U233 fission power versus U233 content.

The momentum spread required to stabilize longitudinal modes in a proposed high-current betatron is computed.

The properties of a coaxial magnetocumulative generator (MCG) in which the current increases exponetially with time are derived and discussed. Such an exponential MCG possess highly desirable performance characteristics that are readily derived and expressed in terms of simple formulas. It is concluded that an exponential MCG may approach a capability of delivering 100 megajoules to a 1 nanohenry load in 1 microsecond.

An eight-pancake Nb-Ti dipole magnet, with bent up ends, called D-108B has been built and tested. This magnet is a Nb-Ti version of a Nb/sub 3/Sn magnet designed to produce a 10-tesla dipole field in a 40 mm diameter aperture. The pancack design is used for the heavy 12,000 ampere Nb/sub 3/Sn cable because of the mechanical difficulty in winding such a heavy cable into the conventional nested cylindrical shell configuration with a 2'' inner winding diameter. The Nb-Ti version operates at 1.8K, in He II, has superconducting cable half as thick as the Nb/sub 3/Sn cable, and operates at half the operating current: 6000 A rather than 12,000 A at 10 tesla. Both magnets are approximately one meter long. D-10B was tested from January 26 to February 2, 1983 and reached short-sample performance in both He I and He II after moderate training. The central field at 4.3K is 7.0 (+- 0.1) tesla, and at 1.8K is 9.1 (+- 0.2) tesla. Ramp rate sensitivity and cyclic heating data were also measured.