Research

CCR’s current hardware research activities include:

  • Corrosion prevention coatings for Navy RF systems
  • Multiple beam electron gun for Ka-Band TWT
  • 5 MW CW RF load for ITER
  • 3D Charged particle code for electron device design
  • 10 MW, 1.3 GHz annular beam klystron
  • High power broadband direct coupler and output window for mm-wave gyrotrons
  • Periodic permanent magnet klystrons for accelerators
  • Advanced design software for photocathodes
  • Segmented magnetron injection gun for gyrotron research
  • 125 kW, C-Band, multiple beam klystron
  • 200+ kV electron gun

Corrosion prevention coatings for Navy RF systems

CCR is funded by the U.S. Navy to mitigate coolant channel corrosion using Atomic Layer Deposition. This research, in collaboration with North Carolina State University (NCSU) is applying nanometer scale ceramic coatings in copper water channels to separate the coolant from the metal surfaces. This eliminates corrosion and erosion caused by poor water quality. It is anticipated this technology will find wide application for ships in the fleet as well as other products for second world and third world countries and remote or mobile applications where high quality water is not available. For more information, please see the following publications. [ Insert link to publication].

Robust, long-life reservoir photocathodes

photocathodeCCR is teamed with the University of Maryland (UMD) to develop long-life, high quantum efficiency (QE) reservoir photocathodes. This builds on previous research which increased the lifetime of cesitated tungsten photocathodes from a few hundred hours to more than 30,000 hours. The current research is focusing on cesium antimonide and potassium cesium antimonide. The current lifetime of these cathodes in less than 20 hours. The goal of this research is to increase lifetimes to more than 500 hours. CCR is assembling facilities to produce these photocathodes for scientific, medical, and industrial applications. More information can be found at [insert link]

Periodic permanent magnet klystrons for accelerators

klystronCCR is advancing klystron technology using an innovative permanent magnet technology. This approach will dramatically improve the overall efficiency of klystrons for many applications, including scientific, industrial, and medical applications. CCR is teaming with Communications & Power Industries, LLC and Varian Medical Systems, Inc. CCR is currently assembling a 6 MW pulsed, S-Band klystron.

The magnetics design approach ensures a high degree of azimuthal field uniformity in the electron beam tunnel, while still providing access to the cavities for water cooling and tuners [reference patent]. It also avoids requirements for shunting, as commonly required for TWTS. This allows use of PPM focusing for high power RF sources.

Advanced design software for photocathodes

CCR is teamed with the Naval Research Laboratory (NRL) and the University of Maryland (UMD) to develop new software for analyzing photocathodes. The goal is to provide a tool to investigate new materials that provide improved performance and to provide information for electromagnetic trajectory codes to simulate the electron bunches/beams produced. Dr. Kevin Jensen is leading the NRL effort and Dr. Eric Montgomery is leading the UMD effort. The code is already finding utility in analyzing unexpected quantum efficiencies in alloys experimentally tested at UMD. We’ll be updating results in our News blog.

125 kW, C-Band, multiple beam klystron

This klystron is nearing completion at CCR and should start producing RF power in fall 2015. The eighteen controlled porosity reservoir (CPR) cathodes operate at 30 A/cm2 with an estimated lifetime of 90,000 hours. The tube operates at 25 kV and will produce millisecond pulses of RF power. The number of cathodes was driven by a relatively large bandwidth requirement, which also required an extended interaction output cavity. For more information please contact Lawrence Ives at rlives@calcreek.com.

Multiple beam gun for Ka-Band Traveling Wave Tube

CCR is developing a multiple beam electron gun for a Ka-Band traveling wave tube (TWT) under investigation at the Naval Research Laboratory (NRL). The gun will employ sixteen controlled porosity reservoir (CPR) cathodes in two rows of eight. The ultimate goal is technology providing relatively high power RF sources with low size and weight. The operating voltage must be less than 6 kV to minimize the power supply requirement, and the program is investigating periodic permanent magnet focusing to reduce weight. Follow our NEWS blog for the latest information on this program.

High power, broadband, direct coupler and output window for mm-wave gyrotrons

CCR is funded by the U.S. Department of Energy to develop new technology for coupling RF power from high power gyrotrons. Traditionally, this power is coupled out using an internal mode converter, a series of focusing mirrors, and a large diamond window. The Gaussian mode power from the gyrotron must then be converted to an HE11 waveguide mode using a Mirror Optical Unit (MOU). MOUs add approximately $500K to the cost of a gyrotron installation, in addition to losing 2-3% of the RF power. CCR is

invented an internal coupler to transition the RF power directly into HE11 waveguide inside the gyrotron. This eliminates

10 MW, 1.3 GHz annular beam klystron

CCR completed assembly of a 10 MW, 1.3 GHz annular beam klystron (ABK) which is awaiting test. The device will be a lower cos treplacement for multiple beam klystrons now used for accelerator applications. It is estimated that the ABK will reduce the klystronCCR-6572 Seal-In Assy. (11)cost by 25%, which would save millions of dollars for large accelerator systems. The ABK is designed to produce 10 millisecond pulses at 10 Hz with an efficiency of 65%. The electron gun used controller porosity reservoir cathodes with an estimate lifetime exceeding 110,000 hours. The cost reduction is achieved using a single, annular cathode with a single beam tunnel. The high perveance achieved with the annular beam (3.4 micropervs) allows operation at 120 kV, equivalent to the MBKs. Follow our NEWS blog for the latest information on this program.

1.5 MW CW RF load for ITER

rf-loadCCR is funded by the U.S. Department of Energy to develop 1.5 MW CW, mm-wave, RF loads for the ITER fusion reactor being built in France. This builds on CCR’s previous development of a 1.2 MW load in 1999 and a 2 MW RF load in 2009. These loads remain the state of the art in RF loads for mm-wave sources. The challenge in the new program is to eliminated braze and O-ring joints between the coolant the internal vacuum. There are also strict imitations on the materials that can be used. These represent unique requirements for RF components where radioactive materials are involved. Follow our news page for the latest information on this program.

  • Robust, long-life reservoir photocathodes
  • 200 kW, 350 MHz multiple beam inductive output tube
  • 5 MW, 1.3 GHz multiple beam klystron