Dr. Andrey D. Andreev enjoyed his profession during the last fifteen years by utilizing his knowledge in applied electromagnetics and plasma physic for studying, designing, and developing a series of novel high-power radio-frequency (RF), microwave, millimeter-wavelength (MMW) and terahertz-frequency vacuum electronic devices (High-Power Electromagnetic (HPEM) sources), as well as their system architectures, components and final products. His last five years have also been spent by participating in planning, organizing, and implementing High-Power Electromagnetic (HPEM) sources in different projects. Previous fifteen years have been spent by exploiting cutting-edge physics approached for design and development new plasma-based high-current pulsed electron-beam accelerators. Phone: 5054505737 Address: 7316 Christy Ave NE, Albuquerque NM 87109
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
The conventional microwave oven with the 2.45 GHz "cooker" magnetron producing output microwave p... more The conventional microwave oven with the 2.45 GHz "cooker" magnetron producing output microwave power of 0.7-1.0 kW has become de-facto one of the "must-have" from the long line of different kitchen appliances available for everyday use in every single US home or office. A problem has arisen, however, during the last 10 years with the rise of numerous wireless systems, most notable of which is the IEEE 802.11/WiFi system, operating at the same frequency 2.45 GHz in a close proximity to the working microwave oven. The problem is called the ElectroMagnetic Interference (EMI) and it is making life really complicated for nearby wireless computer networks and numerous home/office wireless devices. One of the possible solutions of the EMI problem is to redesign the "cooker" magnetron to operate at the frequency located at the outer edge of the Wi-Fi spectrum, 2.48 GHz for example. The paper describes how the modern computer particle-in-cell (PIC) simulations of a conventional double-strapped ten-cavity non-relativistic magnetron may help one to design and build the new 2.48 GHz "cooker" magnetron with the reduced EMI problem to home/office 2.45 GHz wireless devices.
A lightweight, portable 15 MeV electron beam linear accelerator (LINAC) system has been developed... more A lightweight, portable 15 MeV electron beam linear accelerator (LINAC) system has been developed for research applications. Our approach uses a commercial, off-the-shelf magnetron to drive an S-band standing-wave accelerator. The magnetron is driven by a Type-E pulse forming network (PFN), the modulator, switched with a thyratron. Within the modulator macropulse, short (<100 ns), high-frequency (up to 3500 Hz) electron beam pulses are produced by gating the electron current from a triode electron gun. The entire system is contained within approximately 2 m 3 , weighs 250 kg, and can be disassembled into two person-portable components, each weighing 50 kg or less.
ABSTRACT We consider a relativistic magnetron in which all of the resonators of the anode block a... more ABSTRACT We consider a relativistic magnetron in which all of the resonators of the anode block are smoothly continued onto a conical antenna up to the radius corresponding to the cutoff frequency of the radiated wave in a cylindrical waveguide. Such a magnetron is capable of high output power, is compact, has a high resistance to microwave breakdown, is able to work with extremely high currents, and has the possibility of forming desirable output radiation patterns. The magnetic field can be provided by a small solenoid over the resonant system, which is a much smaller volume than is required for the Helmholtz coils used in traditional relativistic magnetrons. The maximum size of this magnetron is the aperture of the horn antenna. The unique aspect of such a design is the possibility of using the horn antenna for conversion of the operating mode to lower order modes, including the TE_11 mode, which is radiated as a narrow wave beam. For a magnetron operating in pi-mode, the mode converter comprises a continuation of the resonantor blocks onto the horn for those resonators that correspond to the symmetry of the output mode. For example, in order to provide Gaussian mode output only two diametrically opposite resonators of even-numbered resonators must be continued onto the horn. In this case the aperture of the horn antenna can be close to the cut-off diameter for the TE_11 mode, and the output power is limited only by breakdown of the output window. In this presentation results of preliminary calculations of the magnetron with output mode converters are presented.
This paper describes a simplified theory of the microwave pulse compressor allowing one to estima... more This paper describes a simplified theory of the microwave pulse compressor allowing one to estimate the microwave power gain G that is possible to achieve inside a resonant cavity of a single-mode microwave pulse compressor utilizing single-arm waveguide Tee.
IEEE International Vacuum Electronics Conference, 2014
More intense than white sauce: loud bump sounds recorded from 2:00-6:17. Smaller bump sounds reco... more More intense than white sauce: loud bump sounds recorded from 2:00-6:17. Smaller bump sounds recorded from 1:40-3:14. Bumping occurred earlier than with white sauce.
Conference Record of the 2006 Twenty-Seventh International Power Modulator Symposium, 2006
ABSTRACT The simplest cross-field ubitron is a magnetically insulated coaxial diode with a cold c... more ABSTRACT The simplest cross-field ubitron is a magnetically insulated coaxial diode with a cold cathode comprising a number of longitudinally oriented single emitters periodically arranged in the azimuthal plane of the diode (a &quot;transparent cathode&quot;). This type of cathode is essentially a wiggler with azimuthally periodic magnetic and electric fields exciting radially oscillating electron currents within the electron flow rotating around the cathode in crossed magnetic and electric fields. The cathode inside the waveguide is also a periodic electro-dynamical system characterized by a set of azimuthal eigenmodes capable of synchronously interacting with the excited radially oscillating currents. Computer simulations of the cross-field ubitron demonstrate controlling microwave generation by changing the external magnetic field with efficiency of &gt;10%. Results of initial experiments are presented
2007 IEEE Pulsed Power Plasma Science Conference, 2007
Summary form only given. It has been experimentally demonstrated that the current-voltage charact... more Summary form only given. It has been experimentally demonstrated that the current-voltage characteristic of a short-pulse electron beam (when the electron beam pulse duration is less than or comparable with the electron time-of-flight between the cathode and anode in the planar geometry of the electron diode) is considerable higher then the conventional Child-Langmuir limit. It can be projected, also, that in the coaxial geometry of electron beam formation, where the Fedosov-Belomytsev current [2] is an analog of the Child-Langmuir current, the 1-V characteristic of a short-pulse electron beam should similarly higher. This means that, when the electron-beam pulse duration is less than or comparable with the characteristic time determining the formation of the steady-state space charge distribution along the electron-beam drift path downstream from the cathode, the total electron beam current should be higher than the appropriate Fedosov-Belomytsev limit. We measured the current-voltage characteristic of nanosecond-duration (10-15 ns) thin tubular relativistic (300-600 keV) electron beams accelerated in vacuum along the axis of a smooth uniform metal tube immersed in a strong axial magnetic field. Results of these measurements as well as results of computer simulations performed using PIC code show that the /-V characteristic at the front of the nanosecond-duration electron-beam pulse is different from the analogous dependence measured at the flat part of the pulse. In the steady-state (flat) part of the pulse, the measured electron-beam current is close to Fedosov-Belomytsev current [2], which is governed by the conservation law of electron momentum flow for any constant voltage. In the non steady-state part (front) of the pulse, the electron-beam current is considerably higher than the appropriate steady-state Fedosov-Belomytsev current and is close to the space-charge-limiting current determining the maximum electron beam current that a metallic tube is capable of- supporting.
An analytical expression for the anode current in a relativistic magnetron is derived. The anode ... more An analytical expression for the anode current in a relativistic magnetron is derived. The anode current is described as the cathode-to-anode drift of the electron guiding centers in the crossed external dc and induced rf magnetic and electric fields. The drift of the electron guiding centers is analyzed in the frame of reference moving with the phase velocity of the induced rf electric field. The anode current determined by this drift is calculated under the assumption that the cathode of the relativistic magnetron operates in a space-charge-limited mode, where the external dc electric field at the cathode surface is zero.
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.
The Journal of microwave power and electromagnetic energy : a publication of the International Microwave Power Institute, 2010
Modern CW industrial heating magnetrons are capable for producing as high as 300 kW of continuous... more Modern CW industrial heating magnetrons are capable for producing as high as 300 kW of continuous-wave microwave power at frequencies around 900 MHz and are sold commercially [Wynn et al., 2004]. However, to utilize these magnetrons in some specific research and scientific applications being of interest for the Air Force, the necessary adaptation and redesign are required. It means that the detailed knowledge of principles of their operation and full understanding of how the changes of the design parameters affect their operational characteristics are necessary. We have developed and tested computer model of a 10-vane high-power strapped magnetron, which geometrical dimensions and design parameters are close to those of the California Tube Laboratory's commercially produced CWM-75/100L tube. The computer model is built by using the 3-D Improved Concurrent Electromagnetic Particle-in-Cell (ICEPIC) code. Simulations of the strapped magnetron operation are performed and the followi...
2007 IEEE Pulsed Power Plasma Science Conference, 2007
ABSTRACT Summary form only given. To provide fast start microwave oscillatios in relativistic mag... more ABSTRACT Summary form only given. To provide fast start microwave oscillatios in relativistic magnetrons, we proposed the transparent cathode, which is essentially a longitudinally slit cylindrical cathode comprising multiple strip electron emitters arranged in a circle. The fast start is achieved due to both cathode and magnetic priming, and the presence of strong electromagnetic field within the electron flow near the electron emitters. We have performed a comprehensive analysis of magnetron operation using computer simulations with the particle-in-cell code MAGIC that have showed the advantage of the transparent cathode implementation over the use of a conventional solid cylindrical cathode.
One class of high-current relativistic HPM devices, the relativistic magnetron [1], provides a lo... more One class of high-current relativistic HPM devices, the relativistic magnetron [1], provides a low-impedance (10-50 Ω) load that inherently needs matching to a low-impedance pulsed-power (Gigawatt or greater) supply to operate with maximum efficiency. One of the most common and reliable pulsed-power drivers used to accomplish this is a Marx generator.
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
The conventional microwave oven with the 2.45 GHz "cooker" magnetron producing output microwave p... more The conventional microwave oven with the 2.45 GHz "cooker" magnetron producing output microwave power of 0.7-1.0 kW has become de-facto one of the "must-have" from the long line of different kitchen appliances available for everyday use in every single US home or office. A problem has arisen, however, during the last 10 years with the rise of numerous wireless systems, most notable of which is the IEEE 802.11/WiFi system, operating at the same frequency 2.45 GHz in a close proximity to the working microwave oven. The problem is called the ElectroMagnetic Interference (EMI) and it is making life really complicated for nearby wireless computer networks and numerous home/office wireless devices. One of the possible solutions of the EMI problem is to redesign the "cooker" magnetron to operate at the frequency located at the outer edge of the Wi-Fi spectrum, 2.48 GHz for example. The paper describes how the modern computer particle-in-cell (PIC) simulations of a conventional double-strapped ten-cavity non-relativistic magnetron may help one to design and build the new 2.48 GHz "cooker" magnetron with the reduced EMI problem to home/office 2.45 GHz wireless devices.
A lightweight, portable 15 MeV electron beam linear accelerator (LINAC) system has been developed... more A lightweight, portable 15 MeV electron beam linear accelerator (LINAC) system has been developed for research applications. Our approach uses a commercial, off-the-shelf magnetron to drive an S-band standing-wave accelerator. The magnetron is driven by a Type-E pulse forming network (PFN), the modulator, switched with a thyratron. Within the modulator macropulse, short (<100 ns), high-frequency (up to 3500 Hz) electron beam pulses are produced by gating the electron current from a triode electron gun. The entire system is contained within approximately 2 m 3 , weighs 250 kg, and can be disassembled into two person-portable components, each weighing 50 kg or less.
ABSTRACT We consider a relativistic magnetron in which all of the resonators of the anode block a... more ABSTRACT We consider a relativistic magnetron in which all of the resonators of the anode block are smoothly continued onto a conical antenna up to the radius corresponding to the cutoff frequency of the radiated wave in a cylindrical waveguide. Such a magnetron is capable of high output power, is compact, has a high resistance to microwave breakdown, is able to work with extremely high currents, and has the possibility of forming desirable output radiation patterns. The magnetic field can be provided by a small solenoid over the resonant system, which is a much smaller volume than is required for the Helmholtz coils used in traditional relativistic magnetrons. The maximum size of this magnetron is the aperture of the horn antenna. The unique aspect of such a design is the possibility of using the horn antenna for conversion of the operating mode to lower order modes, including the TE_11 mode, which is radiated as a narrow wave beam. For a magnetron operating in pi-mode, the mode converter comprises a continuation of the resonantor blocks onto the horn for those resonators that correspond to the symmetry of the output mode. For example, in order to provide Gaussian mode output only two diametrically opposite resonators of even-numbered resonators must be continued onto the horn. In this case the aperture of the horn antenna can be close to the cut-off diameter for the TE_11 mode, and the output power is limited only by breakdown of the output window. In this presentation results of preliminary calculations of the magnetron with output mode converters are presented.
This paper describes a simplified theory of the microwave pulse compressor allowing one to estima... more This paper describes a simplified theory of the microwave pulse compressor allowing one to estimate the microwave power gain G that is possible to achieve inside a resonant cavity of a single-mode microwave pulse compressor utilizing single-arm waveguide Tee.
IEEE International Vacuum Electronics Conference, 2014
More intense than white sauce: loud bump sounds recorded from 2:00-6:17. Smaller bump sounds reco... more More intense than white sauce: loud bump sounds recorded from 2:00-6:17. Smaller bump sounds recorded from 1:40-3:14. Bumping occurred earlier than with white sauce.
Conference Record of the 2006 Twenty-Seventh International Power Modulator Symposium, 2006
ABSTRACT The simplest cross-field ubitron is a magnetically insulated coaxial diode with a cold c... more ABSTRACT The simplest cross-field ubitron is a magnetically insulated coaxial diode with a cold cathode comprising a number of longitudinally oriented single emitters periodically arranged in the azimuthal plane of the diode (a &quot;transparent cathode&quot;). This type of cathode is essentially a wiggler with azimuthally periodic magnetic and electric fields exciting radially oscillating electron currents within the electron flow rotating around the cathode in crossed magnetic and electric fields. The cathode inside the waveguide is also a periodic electro-dynamical system characterized by a set of azimuthal eigenmodes capable of synchronously interacting with the excited radially oscillating currents. Computer simulations of the cross-field ubitron demonstrate controlling microwave generation by changing the external magnetic field with efficiency of &gt;10%. Results of initial experiments are presented
2007 IEEE Pulsed Power Plasma Science Conference, 2007
Summary form only given. It has been experimentally demonstrated that the current-voltage charact... more Summary form only given. It has been experimentally demonstrated that the current-voltage characteristic of a short-pulse electron beam (when the electron beam pulse duration is less than or comparable with the electron time-of-flight between the cathode and anode in the planar geometry of the electron diode) is considerable higher then the conventional Child-Langmuir limit. It can be projected, also, that in the coaxial geometry of electron beam formation, where the Fedosov-Belomytsev current [2] is an analog of the Child-Langmuir current, the 1-V characteristic of a short-pulse electron beam should similarly higher. This means that, when the electron-beam pulse duration is less than or comparable with the characteristic time determining the formation of the steady-state space charge distribution along the electron-beam drift path downstream from the cathode, the total electron beam current should be higher than the appropriate Fedosov-Belomytsev limit. We measured the current-voltage characteristic of nanosecond-duration (10-15 ns) thin tubular relativistic (300-600 keV) electron beams accelerated in vacuum along the axis of a smooth uniform metal tube immersed in a strong axial magnetic field. Results of these measurements as well as results of computer simulations performed using PIC code show that the /-V characteristic at the front of the nanosecond-duration electron-beam pulse is different from the analogous dependence measured at the flat part of the pulse. In the steady-state (flat) part of the pulse, the measured electron-beam current is close to Fedosov-Belomytsev current [2], which is governed by the conservation law of electron momentum flow for any constant voltage. In the non steady-state part (front) of the pulse, the electron-beam current is considerably higher than the appropriate steady-state Fedosov-Belomytsev current and is close to the space-charge-limiting current determining the maximum electron beam current that a metallic tube is capable of- supporting.
An analytical expression for the anode current in a relativistic magnetron is derived. The anode ... more An analytical expression for the anode current in a relativistic magnetron is derived. The anode current is described as the cathode-to-anode drift of the electron guiding centers in the crossed external dc and induced rf magnetic and electric fields. The drift of the electron guiding centers is analyzed in the frame of reference moving with the phase velocity of the induced rf electric field. The anode current determined by this drift is calculated under the assumption that the cathode of the relativistic magnetron operates in a space-charge-limited mode, where the external dc electric field at the cathode surface is zero.
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.
The Journal of microwave power and electromagnetic energy : a publication of the International Microwave Power Institute, 2010
Modern CW industrial heating magnetrons are capable for producing as high as 300 kW of continuous... more Modern CW industrial heating magnetrons are capable for producing as high as 300 kW of continuous-wave microwave power at frequencies around 900 MHz and are sold commercially [Wynn et al., 2004]. However, to utilize these magnetrons in some specific research and scientific applications being of interest for the Air Force, the necessary adaptation and redesign are required. It means that the detailed knowledge of principles of their operation and full understanding of how the changes of the design parameters affect their operational characteristics are necessary. We have developed and tested computer model of a 10-vane high-power strapped magnetron, which geometrical dimensions and design parameters are close to those of the California Tube Laboratory's commercially produced CWM-75/100L tube. The computer model is built by using the 3-D Improved Concurrent Electromagnetic Particle-in-Cell (ICEPIC) code. Simulations of the strapped magnetron operation are performed and the followi...
2007 IEEE Pulsed Power Plasma Science Conference, 2007
ABSTRACT Summary form only given. To provide fast start microwave oscillatios in relativistic mag... more ABSTRACT Summary form only given. To provide fast start microwave oscillatios in relativistic magnetrons, we proposed the transparent cathode, which is essentially a longitudinally slit cylindrical cathode comprising multiple strip electron emitters arranged in a circle. The fast start is achieved due to both cathode and magnetic priming, and the presence of strong electromagnetic field within the electron flow near the electron emitters. We have performed a comprehensive analysis of magnetron operation using computer simulations with the particle-in-cell code MAGIC that have showed the advantage of the transparent cathode implementation over the use of a conventional solid cylindrical cathode.
One class of high-current relativistic HPM devices, the relativistic magnetron [1], provides a lo... more One class of high-current relativistic HPM devices, the relativistic magnetron [1], provides a low-impedance (10-50 Ω) load that inherently needs matching to a low-impedance pulsed-power (Gigawatt or greater) supply to operate with maximum efficiency. One of the most common and reliable pulsed-power drivers used to accomplish this is a Marx generator.
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Papers by Andrey D Andreev