The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We report experimental testing of an active real-time imaging system useful for many practical applications, such as fast security check, food safety inspection, etc. The system consists of a 460-GHz gyrotron capable of producing 16 W in continuous wave operation and a pyroelectric array camera with 124-by-124 pixels. The detailed results obtained from the proof-of-concept experiment with the system...
We report experimental results on a 1.5 MW, 110 GHz, 3 microsecond pulsed gyrotron with a single-stage depressed collector. A simplified mode converter with smooth mirror surfaces has been installed in the tube. The converter was designed with the code SURF3D. We present the hot and cold test results of the internal mode converter. The hot and cold test measurements show good agreement.
Summary form only given. Dynamic nuclear polarization (DNP) is a technique used to enhance the signal-to-noise ratio in nuclear magnetic resonance (NMR) experiments and requires a continuous-wave (CW) source able to generate ten or more watts of power in the 140 to 600 GHz range, a task well suited for gyrotron oscillators. Besides these requirements, a frequency tunable gyrotron is also highly desirable...
In this work we describe the operation of a continuous-wave 330/460 GHz gyrotron oscillator operating at the second harmonic of the electron cyclotron frequency. The oscillator is intended to be used in 700 MHz 1H nuclear magnetic resonance (NMR) experiments enhanced by dynamic nuclear polarization (DNP). At 460 GHz, the gyrotron operates in the TE11,2 mode and is able to generate 16 W of power continuously...
The experimental results of a zero-drive stable, short pulse 140 GHz gyro-traveling wave tube amplifier are presented. The amplifier has achieved a linear gain of 34dB, a saturated bandwidth of over 1.5GHz, and a peak output power up to 800W at a beam voltage of 37kV, beam current of 2.9A, and beam pitch factor of 0.7. The gyro-TWT operates in the HE(0,6) mode of a quasi-optical confocal waveguide.
Dynamic nuclear polarization enhanced nuclear magnetic resonance (DNP/NMR) requires a high power continuous-wave (CW) electromagnetic wave source in the submillimeter wavelength range to obtain significant enhancements in spin spectra from biological samples. Having the ability to generate very high power at submillimeter wavelengths, gyrotrons are well suited for use in DNP/NMR spectrometers1. A...
Gyrotrons operating in the millimeter and submillimeter wavelength ranges are the promising sources for applications that are requiring good spectral characteristics and a wide range of output power. We report the precise measurement results of gyrotron spectra. Experiments were conducted using a 140-GHz long-pulse gyrotron that is developed for the dynamic nuclear polarization/nuclear-magnetic-resonance...
The initial experimental results of a zero-drive stable, short pulse 140 GHz gyro-traveling wave tube amplifier are presented. The amplifier has achieved a linear gain of 31 dB in experiment, and peak output powers up to 400 W have been observed at a beam voltage of 39.5 kV, beam current of 1.65 A, and beam pitch factor of 0.9 from a novel high order HE(0,6) operating mode of a quasi-optical confocal...
The design and simulation results for a 1 kW, 140 GHz gyro-amplifier are presented. A bandwidth of over 4.5 GHz has been achieved in simulation with peak saturated gain of over 52 dB. The HE 06 mode of a confocal cylindrical waveguide is chosen as the operating mode and distributed loss is employed via diffraction to stabilize the circuit. The amplifier will be capable of amplifying short pulses on...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.