LANL, Los Alamos, New Mexico, USA
Compa Industries, Inc., Los Alamos, New Mexico, USA
Texas A&M University, College Station, Texas, USA
A new test facility was designed and constructed at Los Alamos Neutron Science Center (LANSCE) for testing the Thales TH628 Diacrode® and TH781 tetrode power amplifiers. Anode power requirements for the TH628 are 28 kV DC, with peak currents of 190 Amperes in long pulses. A new 225 uF capacitor bank supplies this demand. A charging power supply was obtained by re-configuring a 2 MW beam power supply remaining from another project. A traditional ignitron crowbar was designed to rapidly discharge the 88 kJ stored energy. The anode power supply was extensively tested using a pulsed tetrode switch and resistor load. A new Fast Protect and Monitor System (FPMS) was designed to take samples of RF reflected power, anode HV, and various tube currents, with outputs to quench the HV charging supply, remove RF drive and disable the conduction bias pulse to the grid of each tube during fault events. The entire test stand is controlled with a programmable logic controller, for normal startup sequencing and timing, protection against loss of cooling, and operator GUI.
LANL, Los Alamos, New Mexico, USA
Compa Industries, Inc., Los Alamos, New Mexico, USA
Texas A&M University, College Station, Texas, USA
A prototype VHF RF Final Power Amplifier (FPA) for Los Alamos Neutron Science Center (LANSCE) has been designed, fabricated, and tested. The cavity amplifier met the design goals producing 3.2 MW peak and 480 kW of average power, at an elevation of 2.1 km. It was designed to use a Thales TH628 Diacrode®, a state-of-art tetrode power tube that is double-ended, providing roughly twice the power of a conventional tetrode. The amplifier is designed with tunable input and output transmission line cavity circuits, a grid decoupling circuit, an adjustable output coupler, TE mode suppressors, blocking, bypassing and decoupling capacitors, and a cooling system. The tube is connected in a full wavelength output circuit, with the lower main tuner situated ¾λ from the central electron beam region in the tube and the upper slave tuner ¼λ from the same point. We summarize the design processes and features of the FPA along with significant test results. A pair of production amplifiers are planned to be power-combined and installed at the LANSCE DTL to return operation to full beam duty factor.
LANL, Los Alamos, New Mexico, USA
The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources, a proton radiography facility and a medical and research isotope production facility. The recent operating history of the facility, including both achievements and challenges, will be reviewed. Plans for performance improvement will be discussed, together with the underlying drivers for the ongoing LANSCE Linac Risk Mitigation project. The details of this latter project will be discussed. The status of accelerator-related plans for the MaRIE Project (Matter-Radiation Interactions in Extremes Experimental Project) will also be discussed. Taken together, the LANSCE Linac Risk Mitigation Project and the MaRIE initiative demonstrate a commitment to investment in the ongoing operation and improvement of the facility, and a resurgent interest in the spectrum of science accessible at LANSCE. These plans will assure continued facility operational and scientific vitality well beyond 2020.
LANL, Los Alamos, New Mexico, USA
The LANSCE linear accelerator at Los Alamos National Laboratory has a long history of successful beam operations at 800 kW. We have recently studied options for restoration of high-power operations including schemes for increasing the performance to multi-MW levels. In this paper we will discuss the results of this study including the present limitations of the existing accelerating structures at LANSCE, and the high-voltage and RF systems that drive them. Several plausible options will be discussed and a preferred option will be presented that will enable the first in a new generation of scientific facilities for the materials community. The emphasis of this new facility is "Matter-Radiation Interactions in Extremes" (MaRIE) which will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges.
