Solid-State Modulator R & D at LLNL

Abstract

The Beam Research Program at Lawrence Livermore National Laboratory (LLNL) has been developing solidstate modulators for accelerator applications for several years. These modulators are based on inductive adder circuit topology and have demonstrated great versatility with regard to pulse width and pulse repetition rate while maintaining fast pulse rise and fall times. These modulators are also capable of being scaled to higher output voltage and power levels. An explanation of the circuit operation will be presented along with test data of several different hardware systems.

Sulfide bornite thermoelectric material: a natural mineral with ultralow thermal conductivity

“…As shown in Fig. 5, R/R 0 for Cu 2 S quickly decreases to around 45% aer only 5 s, and to about 10% aer 2000 s. The R/R 0 variation between 60 and 2000 s may be related to the crystal structure transition from hexagonal Cu 2 S to cubic Cu 2Àx S. 43 However, this huge drop in electrical resistance is greatly suppressed in bornite although its crystal structure is similar to Cu 2 S at high temperatures. The electrical resistance in bornite is reduced to 95% aer 1000 s and to 90% aer about 60 000 s, as shown in Fig.…”

Exploring Dynamics in the Far-Infrared with Terahertz Spectroscopy

“…This could even lead to detailed investigation of the nature of the coupling between modes involving secondary structure in proteins such as R-helices and β-sheets. 297 There exist low-frequency intermolecular modes (librons) in amino acid crystals that fall in the far-IR. 298 Given that these are large-amplitude motions, they are expected to be anharmonic and coupled to each other.…”

“…In addition to nonlinear interactions in neat liquids, large molecules of biophysical interest with low-frequency modes in solution will be probed. This could even lead to detailed investigation of the nature of the coupling between modes involving secondary structure in proteins such as α-helices and β-sheets …”

Prototype Inductive Adders With Extremely Flat-Top Output Pulses for the Compact Linear Collider at CERN

“…See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. Livermore National Laboratory in [6], with examples of using modulation techniques for adjusting output waveforms. More recent research on inductive adders, also called inductive voltage adders or linear transformer drivers in the literature, have been carried out for Pockels cells divers for the National Ignition Facility [7], fast kicker systems at the Lawrence Berkeley National Laboratory [7], and industrial applications of pulsed power [9].…”