26156010
An electron accelerator for tunneling through hard rock
Earlier work1-3 demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed.
107968565
MBE-4: an induction linac experiment for heavy ion fusion
The multiple-beam induction linac approach to a heavy ion fusion driver features continuous current amplification along the accelerator and a minimum of transverse beam manipulation from source to pellet. Current amplification and bunch length control require careful shaping of the accelerating voltages. This driver approach exploits developments in electron induction linac technology that have occurred within the last 15 years at LBL, LLNL and NBS. MBE-4 is a four beam induction linac that models much of the accelerator physics of the electrostatically focused section of a considerably longer induction accelerator. Four parallel Cs/sup +/ beams are electrostatically focussed and will be accelerated from 200 keV to approximately one MeV when the experiment is complete in the spring of 1987. The current in each of the four beams will increase from 10 to 40 mA due to both increase in beam speed and shortening of the bunch length. Results of experiments with the injector and first eight accelerating gaps are presented.
41238054
PEP Insertion Quadrupole Design Features
The insertion quadrupoles for the PEP storage ring must have a very uniform gradient to focus the circulating beams to a very small size at the interaction point for high luminosity. Quads have been built which achieve the desired field within the full pole aperture radius to approximately one part in 104. The design features which permitted this achievement are described.
117723646
ROCK EXCAVATION BY PULSED ELECTRON BEAMS
If an intense short pulse of megavolt electrons is deposited in a brittle solid, dynamic spalling can be made to occur with removal of material. Experiments were made on several types of hard rock; results are reproducible and well-described theoretically. An accelerator with a rapidly-pulsed scanning electron beam was designed that could tunnel in hard rock about ten times faster than conventional drill/blast methods.
111218115
Controlling Accelerator Engineering Costs
Cost control for accelerator engineering involves task definition, planning related expenditures, measuring progress, tabulation of costs and projections, and, most important of all, follow-up for corrections. Accelerator engineering costs are best regulated by the accelerator engineer, since those who are in any way detached from the work cannot exercise the most effective control. The accelerator engineer should be assisted by providing him with an effective system, appropriate forms and reports, and administrative support.
33708694
Acceleration of Uranium at the Bevalac
Recent upgrading projects have extended the mass range of particles that can be accelerated at the Bevalac to include any element of the periodic table to energies above 1 billion electron volts per atomic mass unit. This capability was verified on 11 May 1982 with the production of a uranium beam at 147.7 million electron volts per atomic mass unit.
120827387
A measurement of A20 (1320) formation in photon photon collisions
123222571
Measurement of the photon structure function F(2) (gamma) (X, Q**2) between 10-GEV**2 < Q**2 < 60-GEV**2
123050118
$f1(1285)$ formation in photon photon fusion reactions
Abstract We have observed formation of the f 1 (1285) in the reaction e + e - →e + e - π + π - η ( η → γγ ). Its γγ ∗ width is determined in several Q 2 bins. The γγ coupling parameter for the f 1 (1285) is found to be 2.4±0.5±0.5 keV. This value is compared to that for the X (1420), another J =1 state formed in γγ fusion reactions, which may belong to the same meson nonet.