A Dual-Beam Irradiation Facility for a Novel Hybrid Cancer Therapy

In this paper we present the main ideas and discuss both the feasibility and the conceptual design of a novel hybrid technique and equipment for an experimental cancer therapy based on the simultaneous and/or sequential application of two beams, namely a beam of neutrons and a CW (continuous wave) or intermittent sub-terahertz wave beam produced by a gyrotron for treatment of cancerous tumors. The main simulation tools for the development of the computer aided design (CAD) of the prospective experimental facility for clinical trials and study of such new medical technology are briefly reviewed. Some tasks for a further continuation of this feasibility analysis are formulated as well.Comment: 18 pages, 3 tables, 8 figures, 50 reference

A high harmonic gyrotron with an axis-encircling electron beam and a permanent magnet

A gyrotron with an axis-encircling electron beam is capable of high-frequency operation, because the high-beam efficiency is kept even at high harmonics of the electron cyclotron frequency. We have designed and constructed such a gyrotron with a permanent magnet. The gyrotron has already operated successfully at the third, fourth, and fifth harmonics. The frequencies are 89.3, 112.7, and 138 GHz, respectively, and the corresponding cavity modes are TE/sub 311/, TE/sub 411/, and TE/sub 511/. The permanent magnet system is quite novel and consists of many magnet elements made of NbFeB and additional coils for controlling the field intensities in the cavity and electron gun regions. The magnetic field in the cavity region can be varied from 0.97 to 1.18 T. At the magnetic field intensities, the output powers at the third and the fourth harmonics are 1.7 and 0.5 kW, respectively. The gyrotron is pulsed, the pulse length is 1 ms and the repetition frequency is 1 Hz. The beam energy is 40 kV and the beam current is 1.2-1.3 A. Beam efficiencies and emission patterns have also been measured. In this paper, the experimental results of the gyrotron are described and compared with computer simulations

Fundamentals of Electron Cyclotron Resonance and Cyclotron Autoresonance in Gyro-Devices: A Comprehensive Review of Theory

This paper aims to present some selected fundamentals of the theory of a broad class of gyro-devices in a systematic and consistent manner and with sufficient detail necessary for understanding the underlying physical principles of their operation. The focus of this work is on the derivation and analysis of important invariants (constants of motion), as well as on comments concerning their analytical power and the physical insights they provide

Development and Application of THz Gyrotrons for Advanced Spectroscopic Methods

Nowadays, gyrotrons are used in numerous and diverse fields of research and technology. Their most prominent application is to electron cyclotron resonance plasma heating and current drive-in reactors for controlled thermonuclear fusion. Another matured field is the thermal microwave treatment of materials in industrial-grade gyrotron-based technological systems. The unique spectral properties of gyrotron radiation, frequency tunability, and the possibility for precise control and modulation of both the output power and frequency have made the gyrotrons attractive and appropriate radiation sources for various novel advanced spectroscopic techniques. Among them are ESR (electron spin resonance), NMR-DNP (nuclear magnetic resonance with a signal enhancement through dynamic nuclear polarization), XDMR (X-ray detected magnetic resonance), acoustic molecular spectroscopy, as well as high-precision spectroscopy for measuring the SFS (super-fine splitting of the energy levels of positronium). In this review paper, we present both the current status and the most remarkable recent achievements of these methods implemented in gyrotron-based spectroscopy systems and discuss the main trends in the development of their dedicated radiation sources operating in the THz frequency range

Comments on the Physics of Microwave-Undulators

The properties of electromagnetic undulators, produced by the field of a high-power microwave, are discussed. We analyze the conditions to be satisfied that allow the treatment of the emission process by relativistic charges moving through it in full analogy with the case of their static counterparts. We critically review the often claimed possibility of exploiting them in programs aimed at reducing the sizes and costs of an actual free electron laser (FEL) device. We analyze several possible configurations for FELs based on powerful microwave undulators and conclude that the present level of technology, even though not yet mature, should be improved to allow a breakthrough either for low- or high-gain devices

Comments on the Physics of Microwave-Undulators

The properties of electromagnetic undulators, produced by the field of a high-power microwave, are discussed. We analyze the conditions to be satisfied that allow the treatment of the emission process by relativistic charges moving through it in full analogy with the case of their static counterparts. We critically review the often claimed possibility of exploiting them in programs aimed at reducing the sizes and costs of an actual free electron laser (FEL) device. We analyze several possible configurations for FELs based on powerful microwave undulators and conclude that the present level of technology, even though not yet mature, should be improved to allow a breakthrough either for low- or high-gain devices

The Gyrotrons as Promising Radiation Sources for THz Sensing and Imaging

The gyrotrons are powerful sources of coherent radiation that can operate in both pulsed and CW (continuous wave) regimes. Their recent advancement toward higher frequencies reached the terahertz (THz) region and opened the road to many new applications in the broad fields of high-power terahertz science and technologies. Among them are advanced spectroscopic techniques, most notably NMR-DNP (nuclear magnetic resonance with signal enhancement through dynamic nuclear polarization, ESR (electron spin resonance) spectroscopy, precise spectroscopy for measuring the HFS (hyperfine splitting) of positronium, etc. Other prominent applications include materials processing (e.g., thermal treatment as well as the sintering of advanced ceramics), remote detection of concealed radioactive materials, radars, and biological and medical research, just to name a few. Among prospective and emerging applications that utilize the gyrotrons as radiation sources are imaging and sensing for inspection and control in various technological processes (for example, food production, security, etc). In this paper, we overview the current status of the research in this field and show that the gyrotrons are promising radiation sources for THz sensing and imaging based on both the existent and anticipated novel techniques and methods