NEWSLETTERof the International Consortium“Development of High-Power Terahertz
Science & Technology”
February 2019

№ 11

CONTENT Editorial(Page 1)

How to contribute to the Newsletter On the 20th Anniversary of FIR UF Center(Page 2)
 Announcement of International Collaborative Research Program 2019
(Page 14)
 Short invited papers(Page 15,20)
V. Skalyga, S. Golubev, I,VIzotov, M. Glyavin, “Gyrotrons for powerful neutron generators facilities”
A. Kuleshov, E. Khutoryan, S. Ponomarenko, S. Kishko, et al., “Numerical Simulation of sub-THz and
THz Clinotrons”
 Upcoming events (conferences and workshops)(Page 23)
 List of selected recent publications and patents(Page 27)
 New books(Page 34)
 News(Page 35)EDITORIAL: HOW TO CONTRIBUTE TO THE NEWSLETTER
Dear Reader,
We are inviting contributions to the following rubrics:• Research highlights (annotations) presenting the projects pursued by the members of the Consortium.
• Short regular papers.
• Proposals for collaborative research work.
• News from the participating institutions.
• Information about conferences, symposia, workshops, seminars.
• Programs and frameworks for an exchange of visits and mobility of researchers. Job opportunities(especially for young researchers, e.g. postdoctoral positions, specializations, internships).
• Annotations of books, conference proceedings, software and internet resources. Additions to the list of
the recent scientific publications and conference reports at the website of the Consortium(http://fir.ufukui.ac.jp/Website_Consortium/publist.html ).
• Information and announcements about awards and nominations.
• Short presentations of laboratories and research groups belonging to the participating institutions.
Please submit your contributions to the Newsletter as well as requests for information to:Professor Toshitaka Idehara
Supervisor of International Cooperation
and Facilitator of the International
Consortium
FIR UFidehara@fir.u-fukui.ac.jp

Dr. Svilen Sabchevski
Editor of the website and the Newsletter
Institute of Electronics of the Bulgarian
Academy of Sciences
IE-BASsabch@ie.bas.bg

20th ANNIVERSARY OF FIR UF
The Research Center for Development of Far-Infrared region at the University of Fukui(FIR UF Center) was established at the beginning of the academic year 1999/2000 byProfessor Toshitaka Idehara as a founding Director. It is remarkable that at the same time asimilar center at KIT (in Karlsruhe, Germany) led by Professor Manfred Thumm wascreated.
Soon these two institutions became longstanding research partners andcollaborators and now share a common history. In September 1999, the first International
Workshop on Far-Infrared Technologies (IW-FIRT 1999) was held to commemorate the foundation of FUR UF
and to discuss the prospects for development of both the science and the technologies in the most unexplored
region of the electromagnetic spectrum, namely the so-called THz gap. Soon afterward the FIR Center wasrecognized worldwide as one of the leaders in the development, study, and application of gyrotrons operating inthis frequency range. From the very beginning, besides the gyrotrons many other research topics related to the
far-infrared technologies have been pursued as well. Upon the completion of the first five-year period, aninternational panel of distinguished researchers has evaluated positively the work that has been done by the Centerand emphasized its important role both at the national and international level. Such high appraisal based on thesignificant achievements of FIR UF in reaching its goals has open the way to the next stage. It has been marked
by further extension of the research topics to new fields. Recognized as a leading institution the FIR Center has
become an attractive place nationally- and internationally-wide. In the frameworks of the signed bilateral
Agreements for Academic Exchange and Memorandums of Understanding an active international collaboration
with many academic institutions around the world has been promoted. The first International Consortium
organized and led by FIR UF on “Promoting international collaboration for development and application of submillimeter gyrotrons.” Its success demonstrated clearly the advantages of such organization and in 2015 it was
renewed in an extended format. Now, the current International Consortium for Development of High-PowerTerahertz Science and Technology includes 13 institutions from 9 countries from all over the world.
FIR UFThe 20th Anniversary of the FIR Center will be commemorated publishing a booklet with a photo gallery thatreflects its history. For many researchers who have connected their both professional and personal life with thisinstitution now it is time for nice recollections. Below, we present some of the greetings and memorial notes ofsome of them.

CONGRATULATIONS AND SOME PERSONAL REMARKSON THE TWENTIETH ANNIVERSARY OF FIR UF CENTER

Dear colleagues,
On behalf of the IAP RAS team, we would like to send our congratulations and best wishes to the ResearchCenter for Development of Far Infrared Region, University of Fukui (FIR UF) on the occasion of your 20th
anniversary! For us, it is a great pleasure and honor that the history of our collaboration started from the very
foundation of FIR UF by Prof. T. Idehara. In fact, IAP RAS was one of the first among a great number of FIR
UF collaborators to sign an agreement on joint scientific research. Now we can make a remarkable conclusionthat our cooperation has been very fruitful, and we are pleased that it is successfully going on.
Over the past two decades, together we all have created the basis for a new promising scientific direction
dedicated to the development of terahertz-range high power vacuum electronic sources for modern high-power
terahertz techniques. As important milestones on this path, we would like to point out overcoming the “magic”
frequency of 1 THz in the pulse gyrotron, generation at high-order (up to the fifth) cyclotron harmonics in thelarge-orbit gyrotron with a permanent magnet, successful ceramic sintering based on gyrotron and gyro-BWO
systems, the realization of a double-beam gyrotron tube, etc. All these projects were supported by an internationalteam with the active participation of many researchers from IAP. This experience made us happy and proud of
the obtained results. We will not forget our cooperation with such an outstanding person as the first FIR UF
Director Prof. T. Idehara whose contribution was of utmost importance for the success of our joint work. Due tohis efforts and the efforts of Prof. T. Saito and Prof. M. Tani, who continued the guidance of the Center, newhorizons opened for applications of terahertz radiation sources.
Looking back in the past, we would like to note that during this long lasting cooperation friendly relations,and even personal friendships, established. We wish prosperity and success to FIR UF in the future research andgood health and luck to our dear friends and colleagues!

A. G. Litvak, G. G. Denisov, and M. Yu. Glyavin
Institute of Applied Physics RAS, Nizhny Novgorod, Russia

Vladimir Bratman
I was lucky to visit the University of Fukui and work with Prof. T. Idehara and his group shortly before the
FIR Center was established. At that time, there was not yet wonderful new building. In my next visit, it was rapidly
built with the number of floors greater than the number of full-time employees. Then, in front of my eyes, thisbuilding was very quickly filled with advanced installations, on which unique devices were soon created. Over
twenty years of existence of the Center, the researchers have obtained there many of world-class results. Prof. T.
Idehara and his followers Prof. T. Saito and Prof. M. Tani have undoubtedly many reasons for their well-deserved
pride. For me and my colleagues, many years of fruitful cooperation with the Center not only obtained a numberof important results, but also made it possible to get to know Japan quite well, as well as its wonderful people
and centuries-old culture. I am very grateful to Prof. T. Idehara and all employees of the Center for theircooperation and benevolence. I wish you all a long, active and successful work in science and happiness in yourpersonal life.

Mikhail Glyavin
As far as I know, I was the first foreign FIR UF research fellow and, after my initial visit to Fukui in 1999,
I had a total of over 20 visits for more than 3 years. I saw how the Center was built (with my humble participation)
and was very impressed by how quickly the Center established and new scientific results appeared. I would liketo mention that the collaboration with the FIR UF team opened new opportunities for me and encouraged me toconcentrate on the THz science. I took part in several common research projects, which resulted in a great
success in the high frequency gyrotrons development; we published more than 150 journal and conference
proceeding papers together, and I am very thankful to the FIR UF team for excellent conditions for scientificresearch, hospitality, support in all cases (including an unforgettable experience with the Nippon surgery), andfriendship. We not only became real friends, but I became a Nippon guy to some degree; Fukui city became a"hometown" for me, and staying here is my honor and pleasure every time. I wish you good health, long life (asthe history of the Eiheiji Temple), new scientific achievements (as impressive as Mikuni Firework Festival andTojinbo rocks), and of course I hope to continue our collaboration.

Vladimir Manuilov
My story of collaboration with FIR UF is also very long. It started more than 15 years ago after theinvitation of the first Director of the Center Prof. Idehara in 2003. And even during the first days of my stay in
Fukui I was very impressed by the Japanese nature, traditions, culture and language (my first impression wasthat it is like a beautiful and friendly song, especially if some nice Japanese lady says something). Not only suchwell-known places as Asakusa Family Village, Maruoka Castle, Mikuni beach, but even each Japanese homesurrounded by a small beautiful garden attracted my attention. Of course, I remember very interesting andcolorful Tea Ceremonies organized every year at the University Hall and the parties which took place in theCenter with their very friendly and cozy atmosphere. I am very thankful to all staff for their friendship and support,good relations and desire to show all remarkable places not only in Fukui, but all around central Japan, including
such unique places as Kyoto, Nara, Osaka, Nagoya, and Tokyo.
The collaboration with FIR UF team under the leadership of Professors T. Idehara, T. Saito, and M. Tani
opened for me a new and very unique opportunity to widen the area of my scientific activity and to be involvedin many promising projects such as new versions of Large Orbit Gyrotrons, powerful tubes for Collective
Thomson Scattering, and novel terahertz range gyrotrons. I wish new outstanding results to all FIR UF staff andhope that our common efforts will open a new remarkable page in the development of new sources of RF radiation.

Irina Zotova
My story of collaboration with FIR UF is not as long as of some other colleagues, but I have fallen in lovewith this place. I am honored to be the first female professor of the Center and the first participant of the CrossAppointment Scheme. Working in the renowned THz gyrotron center was a great experience which inspired mewith new ideas for further scientific research. I am grateful to Prof. T. Idehara and Prof. M. Tani for inviting me
to the Center and also to Prof. S. Mitsudo and Prof. Y. Tatemasu for creating the atmosphere for fruitful scientificdiscussions.

My memories
Professor Olgierd Dumbrajs
The Research Center for Development of Far -Infrared Region at the University of Fukui (FIR UF) wasestablished in 1999. At that time I was working at the Helsinki University of Technology in Finland. With greatsatisfaction I can mention that I was one of those who wrote a letter of recommendation to Japanese authorities
in favor of establishing the FIR center.
In 2001 26th International Infrared and Millimeter conference took place in Toulouse, France. During theconference Professor T. Idehara approached me and invited me to come to FIR as a visiting professor. I accepted
the invitation with genuine pleasure.
I came to Fukui for the first time in 2002 (01 April - 30 June). In April the new FIR building was not yet
completed. I spent first few weeks in the old building. I was the first visiting professor whose accommodation
was in the University guest house. The accommodation was uninhabited. Professor I. Ogawa helped me verymuch in getting essentials to life and in settling in. Moreover, he helped me to convert my German driver’s license
into Japanese license. On many occasions I rented a car and was driving throughout Japan.
Altogether I visited FIR as a guest professor 10 times, for the last time in 2016 (01 October - 31
December). My first common publication with FIR physicists appeared in 2003, the last one in 2018, the total
number over 20. Common reports at International conferences over 10.
My collaboration with FIR was strengthened when the final version of the Agreement for establishing an
International Consortium for “Development of High – Power Terahertz Science and Technology” was signed by
all participating institutions in October, 2015. At that time I was working at the Institute of Solid State Physics,
University of Latvia, Riga. My institute became one of 13 participating institutions from 9 countries.
During my vacations I travelled extensively all over Japan (Hokkaido, Okinawa, Tokyo, Osaka, Sapporo,
Hiroshima, etc.) and learned the rich culture of the great nation.
My sincere gratitude to FIR founder and first director Professor T. Idehara and his successors for
hospitality. My special thanks to FIR long-term secretary Mrs. Mijuki Morito for her amiability and efficiency.
I wish FIR UF next 20 fruitful years!
O. Dumbrajs,
Leading researcher, Institute of Solid State Physics, University of Latvia.

IW-FIRT 1999

IW-FIRT 2002

My personal recollections on the history of the FIR UF Center and the gyrotronsdevelopment
S.P. Sabchevski

For the first time, I heard about the gyrotrons while studying microwave electron devices at St. Petersburg
State Electrotechnical University. Many years later, in 1997 I met Professor T. Idehara at the International
Conference on Electron-Beam Technologies in Varna (Bulgaria) and was very impressed by his report on thedevelopment of gyrotrons at Fukui University. His enthusiastic and visionary look at the future of these devices
was captivating for me and we started our collaboration. During my first visit to the University of Fukui in
February 1999, Professor Idehara told me that he is going to establish a Research Center for Development of FarInfrared Region (on the basis of the preceding Laboratory for application of superconducting magnet) and invited
me to join his research team. I realized that this is a great opportunity to start work in such promising and very
interesting new field and in September 1999 I arrived in Fukui with my wife Petia and our children Peter and
Joana. We were immediately fascinated by the natural beauty of Japan, its rich culture, traditions, vibrant modern
life, and delicious cuisine – something that has become a lifelong affection. The establishment of the FIR Center
was commemorated by the First International Workshop on Far-Infrared Technologies, which was held in
September 1999. Besides the research work at the Center, as an Associate Professor of the Department of Applied
Physics of the Faculty of Engineering, I conducted two courses of lectures on electron-beam technologies andpropagation of electromagnetic waves, respectively. After my return back to my permanent position at theInstitute of Electronics of the Bulgarian Academic of Sciences (IE-BAS) I have continued my collaboration with
the FIR Center and in the period 2002-2018 was appointed several times as a Visiting Professor and in recent
years as a Specially Appointed Professor and Cross-Appointed Professor. Each of my visits was a great andunforgettable experience! Over the years, the longstanding and fruitful collaboration between FIR UF and IEBAS has been carried out in the framework of the signed agreements for academic exchange, memorandums ofunderstanding and lately using the cross-appointment scheme. IE-BAS is among the 13 institutions from 9
countries worldwide that participate in the International Consortium for Development of High-Power THz
science and Technology, which was established in 2015 by FIR UF. I am very grateful to the first director of FIR
UF Professor Idehara, and his successors Professor Saito, and Professor Tani for their support of the international
collaboration. Together with all other colleagues at FIR UF they have created nice working conditions andstimulating atmosphere. In this respect, I also appreciate very much the contribution of Professor Mitsudo,
Professor Ogawa, Professor Tatematsu, and Professor Yamamoto.
Nowadays, the FIR Center is well recognized worldwide as one of the leaders in the broad field ofdevelopment, study, and applications of gyrotrons. Among the most significant achievements are: (i) the crossingof the symbolic threshold of 1 THz that opened the road of the gyrotrons towards the terahertz frequencies; (ii)development of two series of gyrotrons (Gyrotron FU and Gyrotron FU CW) operating in pulsed and CW regimes,
respectively; (iii) development of a Large Orbit Gyrotron (LOG) with a permanent magnet that operates on thethird, fourth and the fifth harmonics of the cyclotron frequency; (iv) development of a double-beam gyrotron; (v)development of a series of dedicated gyrotrons with internal mode converters and Gaussian output beams (GOseries) for various advanced spectroscopic techniques. Using and studying these devices, significant
advancements in the understanding of the gyrotron physics have been made by the researchers of FIR Center.
They are based on detailed investigations of the: (i) mode interaction (competition, co-operation etc.); (ii)

frequency tunability; (iii) modulation and stabilization of both the output power and frequency; (iv) operation athigh harmonics of the cyclotron frequency. The progress in gyrotron development at FIR UF has opened many
new and even pioneering applications in the high-power terahertz science and technologies that use gyrotrons as
powerful sources of coherent radiation in the sub-THz and THz frequency range. Some of them are: (i) ESR
spectroscopy; (ii) DNP-NMR spectroscopy; (iii) spectroscopy based on X-ray detected magnetic resonance(XDMR); (iv) studies on the hyperfine splitting of positronium; (v) fusion plasma diagnostics based on Thompson
scattering; (vi) sintering of advanced ceramic materials; (vii) novel medical technologies; (viii) study of theeffects of the irradiation of different materials (e.g. C12A7 electride, ZnO single crystals, etc.) by terahertz waves.
I feel privileged and honored for the opportunity to take part in some of the mentioned research topics andprojects. Now, in the eve of the 20th anniversary of the FIR Center, I would like to express my sincere gratitude
to all my colleagues and students at the University of Fukui for the collaboration and friendly attitude wishingthem a further progress in their research, and many remarkable achievements.
Congratulations for 20th anniversary and long life to the FIR Center!

The next collage contains photos provided by Prof. M. Glyavin – a prominentcollaborator of the FIR UF and a devoted cameraman

INTERNATIONAL COLLABORATIVE RESEARCH PROGRAM
Announcement of International Collaborative Research Program 2019
The Research Center for Development of Far-Infrared Region, University of Fukui (FIR UF), hasstarted the International Collaborative Research Program from FY 2017. This program aims to
support the development of the high-power far-infrared region research through the international
personnel exchanges and studies, being performed at the FIR UF in a wide array of fields,
including the development of light sources, applied research, and research and development of
new technologies. FIR UF are now accepting proposals for the FY 2019 (April 2019 – March 2020).
How to apply
Please send an application form (Form 1) through the members of the FIR UF faculty after setting
a research theme and organizing a research team. The deadline for applications is March 31, 2019.
ProcedureTerm: Within one year (from July 1, 2019 to March 31, 2020)
Collaborative research will be performed approximately for two weeks at the FIR UF.
Venue: The Research Center for Development of Far-Infrared Region, University of Fukui
Financial Support: A part of travel expenses and accommodation fee will be covered.
Report: You are expected to submit a one-page research report in A4 sheet.
The number of adoptions is limited. Notice of the adoption will be scheduled around the end of April.
Application to be sent toInternational Collaboration Office, FIR UF
e-mail: int-office＠fir.u-fukui.ac.jp

The Research Center for Development of Far-Infrared Region,
University of Fukui
Director
Masahiko Tani
For detailed information and application forms please follow the link.

SHORT INVITED PAPERS
Gyrotrons for powerful neutron generators facilities
V.A.Skalyga, S.V.Golubev, I,VIzotov, M.Yu.Glyavin*Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS),
Nizhny Novgorod, 603950, Russia*
Corresponding author: glyavin@appl.sci-nnov.ru
Neutron sources are widely used in fundamental and applied research. Manifold applications require
neutron fluxes of various intensities, energy spectra, and degrees of collimation. Several types of neutron sources
have been developed for the purpose including nuclear reactors, radioisotope sources, D-D and D-T generators,
plasma pinch machines, accelerators etc.
The present short invited paper presents the results of recent investigations devoted to the development of
a new generation of compact D-D (D-T) neutron generators capable to generate neutron fluxes that surpass thestate-of-the-art devices by an order of magnitude. The neutron generator consists of the following main parts:
plasma source, electrostatic extraction system for deuterium beam formation/acceleration and the neutrongenerating target containing deuterium or tritium. Improving the performance of each of these subsystems
increases the total neutron flux. According to the present level of neutron generators development, the only
foreseeable method to improve its performance is a significant increase in the ion beam intensity. This, in turn,
could be done by increasing the plasma density in the ion source. Various types of discharges have been studied
earlier for the purpose: RF, Penning, vacuum arc, laser, ECR. Existing state-of-the-art ion sources are able todeliver deuterium beams with the current density up to 100 mA/cm2.
The technological breakthroughs on a number of key components of the gyrotron have led to steadily
increasing performance of the ESR system and, today, ECRH is one of the more viable methods to plasma
heating. At the moment, gyrotrons are the most powerful generator at frequency band from 20 GHz to 1 THz andthe most impressive example are gyrotrons for ITER which produced more than 1 MW/CW at 170 GHz. During
the last 10 years, IAP RAS team developed a series CW setup based on 24-30 GHz tubes for a number oftechnological applications.
Here we suggest using for such purpose a high-current quasi-gasdynamic ECR ion source, which utilizes
powerful gyrotron radiation of mm-waveband for plasma creation and heating. Such ion sources are capable toform ion beams with record current densities of 1 eA/cm2 and low emittance. The reported current density is morethan an order of magnitude greater in comparison to rivaling technologies. Accordingly, the use of quasigasdynamic ion source is expected to increase the density of the neutron flux from the target by a corresponding
factor.

Using powerful mm-waveband radiation allows increasing the plasma density in the discharge
significantly (proportional to the square of the radiation frequency) in comparison to conventional ECRISs, which
utilize microwave radiation with frequencies on the order of 10 GHz. In experiments with 37.5 GHz and 75 GHz
pulsed gyrotrons the plasma density reaches values of 1013 - 1014 cm-3. A sgnificant increase of the plasma density
leads to a change of the confinement mode. So-called quasi-gasdynamic confinement is realized under suchconditions instead of the classical one, which is common for modern ECRISs.
Such discharge conditions allowed to reach extremely high values of ion current density. Using a single aperture
extraction system with a plasma electrode aperture of 10 mm it was possible to produce the deuterium ion beamwith the current of 500 meA, which corresponds to a current density of 650 meA/cm2 at the plasma electrode.
Emittance of the beam measured with a “pepper-pot” method was 0.07 pi-mm-mrad. The ion beam consisted
mainly of deuterons, the ratio of molecular D2+ ions was less than 6% of the total current, which according to ourknowledge surpasses the best results achieved ion sources of any type. Lower ratio of molecular ions in the beamincreases the neutron yield of the target at the same level of thermal load. Measurement of the produced neutron
flux was performed by bombarding of a “heavy ice” target with 300 meA D+ beam accelerated to 50 keV energy.
Under such conditions, the neutron yield was 1010 neutrons per second. This result could be significantly
increased at higher ion beam energies.
The described experiments were performed in pulsed mode. Many applications, however, require a continuous(CW) flux of neutrons. Therefore a completely new system has been built at the IAP RAS. The facility has been
named GISMO (Gasdynamic Ion Source for Multipurpose Operation). It is aimed to produce continuous highcurrent (>200 mA) ion beams with low emittance (<0.2 π∙mm∙mrad). The scheme of the facility is shown in Fig.
1. The key elements of the setup are 28 GHz/10 kW and 37.5 GHz/20 kW (after an upgrade within the next year)
CW gyrotrons manufactured by Gycom. These microwave generators are equipped with power supplies suitablefor CW or pulsed operation. A fully permanent magnet magnetic trap is used for plasma confinement. For
effective plasma heating, a set of requirements were applied to the system. Magnetic field configuration was
designed to be similar to a simple mirror trap close to the system axis with field strength at magnetic mirrors notless than 1.4 T and not less 0.2 T at the trap center. The distance between magnetic mirrors should be about 1215 cm. The mirror ratio should be in the range 3 ≤ Bmax / Bmin ≤ 7. The inside diameter must be not less than 5
cm in order to allow assembling together with an insulated plasma chamber with a minimum diameter of 4 cm.
For ion beam extraction it is planed to use a 4-electrode system with maximum acceleration voltage up to 100
kV. Such extraction requires the development of appropriate high-voltage insulation of the discharge chamberfrom other parts. In this regard, one of the key elements of the installation is the DC-break of the microwave
transmission line. It was proposed to implement a quasioptical system shown in Fig. 1. The electromagnetic
radiation of the gyrotron (mode TE21) is fed to the converter to Gaussian beam. The Gaussian beam passes throughthe air gap of 15 cm which is used as a DC-break. After that gap, the radiation goes to the converter into TE11
mode of a circular waveguide and then to a microwave coupling system implemented with the plasma chamber.
Overall transmission efficiency of the microwave line, DC-break and microwave injection system is 94%. The

plasma chamber is 30 cm in length and 4 cm in diameter. It is equipped with water cooling along the wholesurface from the coupling system to the flange.

Fig. 1. Scheme of the GISMO 28 CW high current ion source.
The first plasma at GISMO facility was ignited in June 2018. In the future, it is expected that GISMO would
be able to generate deuteron ion beams with 1 eA current and 100 keV energy. Modern neutron-generating targets
consist of a substrate coated with a metal which can effectively absorb deuterium (such as Ti). The performanceof these commercially available targets is about 108 neutrons/second per 1 mA current of the incident deuteronbeam accelerated to an energy of 100 keV. Thus, the bombardment of such target by a desirable deuteron beamwould theoretically yield a neutron flux up to 1011 s-1. Also the possibility of using gaseous targets is underinvestigations now to reach higher neutron yields without tritium.
One of the most interesting and important applications of high yield neutron generators discussed above
is boron-neutron capture therapy (BNCT) of oncologic diseases. The main problem hindering the developmentof BNCT is the necessity of neutron fluxes over 109 s-1·cm-2. The only machines able to produce the required
neutron flux are nuclear reactors and large-scale accelerators plagued by tremendous price and strict safety rules
for protecting the staff and patients. The D-D neutron generator scheme discussed here is free of those
shortcomings as it does not use radioactive isotopes including tritium and/or high energy particles, thus not
requiring heavy X-Ray shielding. Moreover, the device has a compact size allowing it to be installed in literally
any existing clinic and has a significantly lower price in comparison to the aforementioned technologies. In
summary, a neutron generator based on high-current quasi-gasdynamic ECR ion (deuterium) source with plasma
heating by powerful gyrotron radiation could be very perspective for BNCT application.
Another application of high-density neutron fluxes is neutronography [59-60], one of the most importantachievements of nuclear physics over the past decades. It provides great opportunities in micro-analysis of not
only physical but also chemical and biological entities. Structural neutronography is a well-developed and widelyused method of crystal structure analysis. The emergence in recent years of high neutron flux nuclear reactors,

Fig. 2. General view of the GISMO 28 CW high current ion source (gyrotron part to the right and plasma
camera to the left side).
computer-controlled automatic neutron diffractometers and specialized data processing software have greatly
expanded the possibilities of structural neutronography and have led to a sharp increase of interest in it byphysicists, chemists, biologists, metallurgists, etc.. The development of a compact high yield neutron generator
could facilitate further developments of neutronography methods in laboratory conditions, previously available
at nuclear reactors and large-scale accelerator facilities, thus greatly increasing the accessibility of this analysis
method. Also, pulsed neutron generators with high yield could be very prospective for such kind of applications.

For additional information, please see the following reference:

S.V. Golubev, I.V. Izotov, S.V. Razin, A.V. Sidorov, V.A. Skalyga, “A Compact Neutron Source for Boron
Neutron Capture Therapy,” Radiophysics and Quantum Electronics, vol. 59, n. 8-9 (2017) 682–689. DOI:
10.1007/s11141-017-9735-9.

Numerical Simulation of sub-THz and THz Clinotrons
Alexei N. Kuleshov*, Eduard M. Khutoryan, Sergey S. Ponomarenko, Sergey A. Kishko, Alexander A.
Likhachev, Alexander A. Danik, Yurii S. Kovshov
O. Ya. Usikov Institute for Radiophysics and Electronics of NAS of Ukraine
Vacuum Electronic Department
Research & Development Team on MW and THz Tubes
12 ac. Proskura st., Kharkov 61085, Ukraine, tel. lab: +38057 7203570, fax: +38057 3152105
Corresponding autor: jeanalexkh@gmail.com
Currently, our research activity is connected with the computer modeling for the sub-THz and THz CW
clinotrons and verification of the obtained simulation data using the statistical processing of real device
operational parameters. Recently developed simulation model considers several important effects occurring inclinotron tube. Among them are: the effect of a weakly inhomogeneous magnetic field; the effect of the surface
roughness and thermal heating of the grating structure; the effect of wave reflections and transformation of surface
slow modes into fast ones in the clinotron cavity resonator. The carried out 3D particle tracking simulation
demonstrated the electron beam adjustment in clinotron oscillator in the case of different distributions of the
focusing magnetic field, and provided the velocity distributions in the beam that have been accounted in the
beam-wave interaction model. The value of high-frequency ohmic losses has been evaluated in the framework of
3D thermal heating analysis in clinotron and the experimental investigation of the surface roughness appearing
in the grating structure manufactured with the wire-EDM processing. Theory of sub-THz and THz clinotrons was
extended by use of the modes scattering matrix in ends of the oversized clinotron cavity resonator. Because ofreflection and transformation of surface slow modes into fast ones, such theory reveals resonant behavior ofclinotron even in the case of strong attenuation of the surface mode. We analyzed resonances both by fast waves
with low loss and surface wave appearing in the collector area of the grating because of fast wave transformation.
Also scattering matrix in the grating gun area (FIG. 1. a) enables evaluating of power propagating through anodeslot into the cathode area. Results of simulations are in good agreement with conducted experiments (FIG. 1. b,

(a)
(b)
310
305

Experimentf (GHz)Dispersion

300

Simulation

295
290
285

3600

4000

Voltage (V)

4400

4800

(c)
FIG. 1. Simulation model of the power output section (a); Experimental and simulation results obtained for 300
GHz CW Clinotron Tube.

c). Using the developed theory, we plan to optimize the geometry of the output section to maximize the power
portion into the output waveguide.
Development of High-Voltage Power Supply with High Stability
Due to the dispersion properties of slow-wave structures applied in clinotrons the high-voltage instability ofthe electron beam significantly affects their operating parameters. To improve the spectra quality of the clinotron
we have developed a compact high-voltage power supply with the voltage stability better than 20 ppm in theaccelerating voltage range from 0.5 to 6 kV (FIG. 2). The compact high-voltage power supply employs the
microcontroller scheme providing the remote control and data communications via USB using standard software
packages such as National Instruments LabVIEW and etc.
The developed HV power supply for the clinotron allows us to realize the developed PID controller scheme.
In order to stabilize the clinotron output power, the simplest way is to provide the feedback in beam current circuit
controlling the filament current in the case of stabilized high-voltage. In this case, the stabilization of the beam
current with the negligible effect of thermal shifts of the electromagnetic system at a fixed frequency will resultin the stabilization of output power. The stabilization of the beam current in the case of thermionic emission isrealized due to the control of filament current. Also, the inertia of the system provides a serious limit in the caseof the stabilization of output power with fast changes. In such a case, it is required to use the double PID control,
which can be realized in the clinotron with three-electrode electron gun. Output power value measured with thehelp of both the waveguide coupler and the power meter is compared with desired value and the PID controller
provides the feedback in filament power supply scheme.

(a)(b)
FIG. 2. High-voltage power supply developed for sub-THz and THz CW Clinotrons (left). The output
voltage stability of the power supply (right).
Development of Compact CW Radiation Modules for THz Applications
Sub-THz and THz Clinotrons generate radiation with the output power higher than in mass-produced
conventional BWO more than an order under the close parameters of electronic tuning of the oscillation frequency
in a wide range. These advantages show the attractive opportunity to use the clinotron tubes in different system
employed for THz applications. Recently we have developed and manufactured the compact radiation modules
based on the clinotron oscillators with the output power up to 100 mW in the frequency range from 290 to 370
GHz (FIG. 3. a, FIG. 4. a). The “hot” simulation has been carried out and the results were used during theclinotrons design optimization. The results were used to estimate the effect of beam voltage instability on thefrequency fluctuation and to define the required stability of the clinotron power supply. In this connection, thehigh-voltage power supply with stability of 20 ppm has been employed in the Compact CW Radiation Modules.
The spectra quality of the output electromagnetic radiation has been studied experimentally and is shown in FIG.
3. (b) and FIG. 4. (b). The long-term frequency stability < 40 ppm has been observed during the clinotrons
operation within several hours that satisfies the requirements for DNP-NMR spectroscopy. The Compact CW
Radiation Modules have remote control and data communication via USB connection therefore the additional
external PID-control scheme can be implemented for the improved frequency and power stabilization.

(b)
(a)
FIG. 3. Compact CW Radiation Module for THz Applications based on 340 GHz CW Clinotron (a) and theiroscillation spectra (b).

(a)(b)
FIG. 4. Compact CW Radiation Module for THz Applications based on 300 GHz CW Clinotron (a) and theiroscillation spectra (b).
References
1. Y. S. Kovshov, S. S. Ponomarenko, S. A. Kishko, E. M. Khutoryan and A. N. Kuleshov, "Numerical
Simulation and Experimental Study of Sub-THz and THz CW Clinotron Oscillators," in IEEE Transactions
on Electron Devices, vol. 65, no. 6, pp. 2177-2182, June 2018.
2. Kovshov, Y.S., Ponomarenko, S.S., Kishko, S.S. et al., J Infrared Milli Terahz Waves (2018) 39: 1055.
DOI:10.1007/s10762-018-0534-y
3. Khutoryan, E.M., Kovshov, Y.S., Likhachev, A.S. et al., J Infrared Milli Terahz Waves (2018) 39: 236.
DOI:10.1007/s10762-017-0453-3
4. Y. Kovshov et al., "Tracking Analysis of a Sheet Electron Beam for Clinotron Tube," 2018 IEEE 17th
International Conference on Mathematical Methods in Electromagnetic Theory (MMET), Kiev, 2018, pp.
330-333.

5. Y. Kovshov et al., "Electron Beam Velocity Spread Effect on a Clinotron Operation," 2018 IEEE 17th
International Conference on Mathematical Methods in Electromagnetic Theory (MMET), Kiev, 2018, pp.
326-329.
6. Y. Kovshov et al., "Demonstration of a Mode Transformation Effect in 300-GHz CW Clinotron," 2018 IEEE
17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET), Kiev, 2018,
pp. 254-257.
7. Y. Kovshov et al., "0.1–0.4 THz clinotron table-top modules for spectroscopy applications," 2017 IEEE
International Young Scientists Forum on Applied Physics and Engineering (YSF), Lviv, 2017, pp. 275-278.

FORTHCOMING EVENTSThe International Workshops on Far-Infrared Technologies (IW-FIRT) has been held six times in the pastfrom 1999 to 2017. In these workshops it was aimed to discuss the recent development and future directionsof far-infrared and terahertz science and technologies with a special emphasis on high power radiation sourcesin this frequency region and their applications. We feel that it is the time to organize the next IW-FIRT to
update our knowledge and understanding in this rapidly developing field. Therefore, we organize the SeventhInternational Workshop on Far-Infrared Technologies (IW-FIRT 2019).
The workshop consists of invited talks, oral presentations and a poster session with the following scope of
topics:1) Development of high power radiation sources in the far-infrared region,2) Application of high power terahertz technologies especially to the following topics
2-1) Terahertz spectroscopy,2-2) Magnetic resonance phenomena in the far-infrared region,2-3) Material development with high-power FIR sources, and3) Other subjects related to the far-infrared region.
Past Workshops of IW-FIRT and DHP-TST:
6th IW-FIRT 2017 and DHP-TST 2017, 5th IW-FIRT 2014, 4th IW-FIRT 2012, 3rd IW-FIRT 2010, and
DHP-TST 2013.
Venue: Bunkyo Campus, University of Fukui (Fukui, Japan). Main conference room and poster session: On the
13th floor of the Science Tower I (No.24 in the campus map). Workshop banquet: At the academy hall (No.11 in
the campus map)

List of invited speakers (In alphabetical order of family names):
Marco Battiato (Nanyang Technological Univ., Singapore)
Elmer S. Estacio (The Univ. of the Philippines Diliman, Philippines)
Gerd Gantenbein (IHM, Karlsruhe Institute of Technology, Germany)
Mikhail Yu. Glyavin (Institute of Applied Physics, RAS, Russia)
Jarno Järvinen (Univ. of Turku, Finland)
Tae-In Jeon (Korea Maritime and Ocean Univ., Korea)
Yusuke Kajihara (The Univ. of Tokyo, Japan)
Shojiro Kimura (Tohoku Univ., Japan)
Stefan Knirck (Max-Planck-Institut für Physik, Germany)
Masami Kojima (Kanazawa Medical Univ., Japan)
Seitaro Mitsudo (FIR UF, Japan)
Yuichi Ogawa (Kyoto Univ., Japan)
Hitoshi Ohta (Kobe Univ., Japan)
Michael Shapiro (Massachusetts Institute of Technology, USA)
Kohei Shimamura (Univ. of Tsukuba, Japan)
Yukihisa Suzuki (Tokyo Metropolitan Univ., Japan)
Susumu Takahashi (Univ. of Southern California, USA)
Masahiko Tani (FIR UF, Japan)
Yoshinori Tatematsu (FIR UF, Japan)
Keisuke Tominaga (Kobe Univ., Japan)
Johan van Tol (National High Magnetic Field Laboratory, Florida State Univ., USA)For up-to-date information of the Workshop please visit the link and contact by an E-mail the Secretariat:
iwfirt2019_secretariat@fir.u-fukui.ac.jp.

IRMMW-THz 201944th International Conference on Infrared, Millimeter, and Terahertz Waves
Paris, France, 1-6 September 2019

For detailed information visit the website of the conference following the link

The 29th International Crimean Conference “Microwave and Telecommunication
Technology”

The 29th International Crimean Conference “Microwave and Telecommunication Technology”
will be held in the city of Sevastopol, Russia from 8 to 14 September 2019.
The conference has been held in Sevastopol since 1991. For 28 years, the conference has becomea well-known forum where in 2018 alone over 300 reports were presented on theoretical,
experimental, industrial and technological, applied and historical aspects of microwave
equipment and telecommunication technologies. The authors of these reports are 606 scientists
and specialists, representing 126 universities and enterprises in 9 countries: Armenia, Belarus,
Great Britain, China, the Netherlands, Russia, the USA, Ukraine and Sweden. A collection ofmaterials was published annually, for 28 years, 9060 reports were published in the conferencematerials, the authors of which are scientists and specialists of about 800 universities andenterprises in 43 countries (8 CIS countries and 35 foreign countries). Conference materials areindexed and refereed by many reputable databases, including the Scopus database.
For more detailed information please visit the conference website at the following link.

The 20th International Vacuum Electronics Conference (IVEC 2019)

For more detailed information please visit the conference website at the following link

LIST OF SELECTED RECENT PUBLICATIONS
Bibliography and links to selected recent publications on topics related to the research field of theInternational Consortium and published after October 2018, i.e. after issuing the previous Newsletter #10.
This cumulative list is in chronological order as collected from various bibliographical and alert services
A. Publications by authors from the institutions participating in the International Consortium
Mishakin S.V., Samsonov S.V., "An Approach to Thermal Analysis of Helically Corrugated Waveguide
Elements of Vacuum Electron Devices," IEEE Trans. on Microwave Theory and Techniques, (2018). DOI:
10.1109/TMTT.2018.2873362.
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8501579&isnumber=4359079
Zapevalov V.E., “Non-Canonical Gyrotrons,” Radiophysics and Quantum Electronics, (2018). DOI:
10.1007/s11141-018-9888-1.
https://link.springer.com/article/10.1007%2Fs11141-018-9888-1
Girka I., Kondratenko V., Thumm M., “Higher radial modes of azimuthal surface waves in magnetoactive
cylindrical plasma waveguides,” Journal of Plasma Physics, vol. 84 n. 6 (2018) 905840603. DOI:
10.1017/S0022377818001101.
https://www.cambridge.org/core/journals/journal-of-plasma-physics/article/higher-radial-modes-of-azimuthalsurface-waves-in-magnetoactive-cylindrical-plasma-waveguides/DFA1AE03A26482EE834B3C1F0F80936E
Knirck S., Yamazaki J., Okesaku Y., Asai S., Idehara T., Inada T., "First results from a hidden photon dark mattersearch in the meV sector using a plane-parabolic mirror system," Journal of Cosmology and Astroparticle Physics,
vol. 2018, n. 11 (2018). DOI:10.1088/1475-7516/2018/11/031.
http://iopscience.iop.org/article/10.1088/1475-7516/2018/11/031/meta
Rumyantsev V.V., Dubinov A.A Fokin., A.P., Utochkin V.V., Glyavin M.Yu., Morozov S.V., “Doubling of
gyrotron radiation frequency due to nonlinear susceptibility in A3B5 semiconductors,” EPJ Web Conf., vol. 195(2018) 02010. DOI:10.1051/epjconf/201819502010.
https://www.epjconferences.org/articles/epjconf/abs/2018/30/epjconf_tera2018_02010/epjconf_tera2018_02010.html
Glyavin M.Yu., Denisov G.G., Khazanov E.A., “From millimeter to microns – IAP RAS powerful sources forvarious applications,” EPJ Web Conf., vol. 195 (2018) 00001. DOI: 10.1051/epjconf/201819500001.
https://www.epjconferences.org/articles/epjconf/abs/2018/30/epjconf_tera2018_00001/epjconf_tera2018_00001.html
Bogdashov A., Fokin A., Fedotov A., Glyavin M., Morozkin M., Novozhilova Yu., Proyavin M., Rozental R.,
Sedov A., Tsvetkov A., Zotova I., Denisov G., “Frequency control in subterahertz gyrotrons,” EPJ Web Conf.,
vol. 195 (2018) 01005. DOI: 10.1051/epjconf/201819501005.
https://www.epjconferences.org/articles/epjconf/abs/2018/30/epjconf_tera2018_01005/epjconf_tera2018_01005.html
M. Morozkin, G. Denisov, E. Tai, E. Soluyanova, A. Sedov, A. Fokin, A. Kuftin, A. Tsvetkov, M. Bakulin, E.
Sokolov, V. Malygin, M. Proyavin, V. Zapevalov, O. Mocheneva, M. Glyavin, “Development of the Prototypeof High Power Sub-THz Gyrotron for Advanced Fusion Power Plant (DEMO),” EPJ Web Conf., vol. 195 (2018)
01008. DOI:10.1051/epjconf/201819501008.
https://www.epjconferences.org/articles/epjconf/abs/2018/30/epjconf_tera2018_01008/epjconf_tera2018_01008.html

Zavolsky N.A., Zapevalo V.E., Zuev A.S. et al., “Analysis of the Methods of Discrete and Smooth Frequency
Tuning in Gyrotrons for Spectroscopy, on the Example of a Generator Operated in the 0.20–0.27 THz Frequency
Range,” Radiophys Quantum Electronics, (2018).DOI:10.1007/s11141-018-9905-4.
https://link.springer.com/article/10.1007%2Fs11141-018-9905-4
Fedotov A.E., Zotova I. V., Glyavin M. Yu., Rozental R. M., Zuev A. S., Ginzburg N. S., Sergeev A. S., IdeharaT., “Frequency Tunable sub-THz Gyrotrons for Spectroscopy Applications,” EPJ Web Conf., vol. 187 (2018)
01025. DOI: 10.1051/epjconf/201818701025.
https://www.epjconferences.org/articles/epjconf/abs/2018/22/epjconf_rgm2018_01025/epjconf_rgm2018_01025.html
A. Bertinetti, F. Albajar, K.A. Avramidis, F. Cau, F. Cismondi, G. Gantenbein, J. Jelonnek, P.C. Kalaria, S. Ruess,T. Rzesnicki, L. Savoldi, R. Zanino, “Analysis of an actively-cooled coaxial cavity in a 170 GHz 2 MW gyrotron
using the multi-physics computational tool MUCCA,” Fusion Engineering and Design, (2018). DOI:
10.1016/j.fusengdes.2018.11.033.
https://www.sciencedirect.com/science/article/pii/S0920379618307373
Yu.V. Bykov, A.G. Eremeev, S.V. Egorov, V.V. Kholoptsev, I.V. Plotnikov, K.I. Rybakov, A.A. Sorokin, “Ultrarapid microwave sintering,” Journal of Physics: Conference Series, vol. 1115 (2018) 042005. DOI:10.1088/17426596/1115/4/042005.
http://iopscience.iop.org/article/10.1088/1742-6596/1115/4/042005/meta
V.L. Bratman, A.E. Fedotov, Yu.K. Kalynov, V.N. Manuilov, “Prospective THz Gyrotrons for High-Field
Magneto-Resonance Spectroscopy,” EPJ Web Conf., vol. 95 (2018) 01003. DOI: 10.1051/
epjconf/201819501003.
https://epjwoc.epj.org/articles/epjconf/abs/2018/30/epjconf_tera2018_01003/epjconf_tera2018_01003.html
Kuzikov S.V., Savilov A.V., "Regime of "multi-stage" trapping in electron masers, "Physics of Plasmas, vol. 25,
n.11 (2018) 113114. DOI:10.1063/1.5049880.
https://aip.scitation.org/doi/10.1063/1.5049880
Rozental R.M., Zotova I.V., Ginzburg N.S., Sergeev A.S., Tarakanov V.P., “Generation of Electromagnetic
Rogue-Waves in Submillimeter-Band Gyrotrons,” J Infrared Milli Terahz Waves, vol. 40, n.2 (2018) 150–157.
DOI:10.1007/s10762-018-0561-8.
https://link.springer.com/article/10.1007%2Fs10762-018-0561-8
Gantenbein G., Avramidis K., Illy S., Ioannidis Z.C., Jin J., Jelonnek J., Kalaria P., Pagonakis I.Gr., Ruess S.,
Ruess T., Rzesnicki T., Thumm M., Wu C., “New trends of gyrotron development at KIT: An overview on recent
investigations,” Fusion Engineering and Design, (2018). DOI:10.1016/j.fusengdes.2018.12.063.
http://www.sciencedirect.com/science/article/pii/S0920379618308263
Ioannidis Z.C., Albajar F., Alberti S., Avramidis K.A., et al., “Recent experiments with the European 1MW,
170GHz industrial CW and short-pulse gyrotrons for ITER,” Fusion Engineering and Design, (2019). DOI:
10.1016/j.fusengdes.2018.12.065.
http://www.sciencedirect.com/science/article/pii/S0920379618308299
Ruess T., Avramidis K.A., Gantenbein G., Ioannidis Z., et al., “Computer-Controlled Test System for the
Excitation of Very High-Order Modes in Highly Oversized Waveguides,” Journal of Infrared, Millimeter, andTerahertz Waves, (2019). DOI:10.1007/s10762-018-0566-3.
https://link.springer.com/article/10.1007/s10762-018-0566-3
Golubev S.A., et al “Pulsed neutron generator with a point-like emission area based on a high-current ECR sourceof deuterium ions,” JINST 14 (2019) C01007. DOI: 10.1088/1748-0221/14/01/C01007.
http://iopscience.iop.org/article/10.1088/1748-0221/14/01/C01007/metaKulygin M., "Stress Test of Nanosecond Semiconductor Cavity Switches with Subterahertz Gyrotrons," IEEE
Trans.on Terahertz Science and Technology, (2019). DOI:10.1109/TTHZ.2019.2891020.
https://ieeexplore.ieee.org/abstract/document/8601305
Kovshov Y. S., Ponomarenko S.S., Kishko S.S., Likhachev A., Danik A., Mospan L., Steshenko S., Khutoryan
E.M., Kuleshov A.N., "Effect of Mode Transformation in THz Clinotron," Journal of Infrared, Millimeter, andTerahertz Waves, vol. 39, n. 11 (2018) 1055-1064. DOI: 10.1007/s10762-018-0534-y.
https://link.springer.com/article/10.1007/s10762-018-0534-y
Wu C., Pagonakis I. G., Avramidis K. A., Gantenbein G., Illy S., Thumm M., Jelonnek J., “ Gyrotron multistage
depressed collector based on E×B drift concept using azimuthal electric field, I. Basic design, Physics of Plasmas,
2vol. 5 n. 3 (2018) 033108. DOI: 10.1063/1.5016296.
https://aip.scitation.org/doi/abs/10.1063/1.5016296
Maksimenko A.V., Shcherbinin V.I., Hlushchenko A.V., Tkachenko V.I., Avramidis K.A., Jelonnek J., "Starting
Currents for Eigenmodes of a Gyrotron Cavity With Mode Conversion," IEEE Trans. on Electron Devices (2019).
DOI:10.1109/TED.2019.2893888.
https://ieeexplore.ieee.org/document/8630824
V.L. Bratman, Yu.K. Kalynov, O.P. Kulagin, A.N. Leontyev, P.B. Makhalov, V.N. Manuilov, I. V Osharin, A.V.
Savilov, A.E. Fedotov, A.P. Fokin, A.V. Chirkov, “A Compact THz Source for Enhancing the Sensitivity of
Nuclear Magnetic Resonance Spectroscopy with Dynamic Nuclear Polarization,” Bulletin of the Russian
Academy of Sciences: Physics, vol. 82, n. 12 (2018) 1592–1595. Original Russian Text: V.L. Bratman, Yu.K.
Kalynov, O.P. Kulagin, A.N. Leontyev, P.B. Makhalov, V.N. Manuilov, I.V. Osharin, A.V. Savilov, A.E.
Fedotov, A.P. Fokin, A.V. Chirkov, 2018, published in Izvestiya Rossiiskoi Akademii Nauk, Seriya Fizicheskaya,
2018, Vol. 82, No. 12, pp. 1760–1765.DOI:10.3103/S1062873818120274.
https://link.springer.com/article/10.3103%2FS1062873818120274
I.V. Bandurkin, V.L. Bratman, Yu.K. Kalynov, Yu.S. Oparina, I.V. Osharin, N.A. Zavolsky, A.V. Savilov,“Terahertz Gyrotrons at High Cyclotron Harmonics with Irregular Electrodynamic Systems,” Bulletin of theRussian Academy of Sciences: Physics, vol. 82, n. 12 (2018) 1582–1586. Original Russian Text: I.V. Bandurkin,
V.L. Bratman, Yu.K. Kalynov, Yu.S. Oparina, I.V. Osharin, N.A. Zavolsky, A.V. Savilov, 2018, published in
Izvestiya Rossiiskoi Akademii Nauk, Seriya Fizicheskaya, 2018, Vol. 82, No. 12, pp. 1748–1753.
DOI:10.3103/S1062873818120250.
https://link.springer.com/article/10.3103%2FS1062873818120250
S.V. Kuzikov, A.V. Savilov, “Terahertz Gyrotrons at High Cyclotron Harmonics with Irregular Electrodynamic
Systems,” Bulletin of the Russian Academy of Sciences: Physics, vol. 82, n. 12 (2018) 1596–1599. Original
Russian Text: S.V. Kuzikov, A.V. Savilov, 2018, published in Izvestiya Rossiiskoi Akademii Nauk, Seriya
Fizicheskaya, 2018, Vol. 82, No. 12, pp. 1766–1770.DOI:10.3103/S1062873818120298.
https://link.springer.com/article/10.3103%2FS1062873818120298
I.V. Bandurkin, I.S. Kurakin, Yu.S. Oparina, A.V. Savilov, V.L. Bratman, N. Balal, Yu. Lurie, “Terahertz
Undulator Radiation of Stabilized Dense Electron Beams”, Bulletin of the Russian Academy of Sciences: Physics,
vol. 82, n. 12 (2018) 1587–1591. Original Russian Text: I.V. Bandurkin, I.S. Kurakin, Yu.S. Oparina, A.V.
Savilov, V.L. Bratman, N. Balal, Yu. Lurie, 2018, published in Izvestiya Rossiiskoi Akademii Nauk, Seriya
Fizicheskaya, 2018, Vol. 82, No. 12, pp. 1754–1759. DOI: 10.3103/S1062873818120262.
https://link.springer.com/article/10.3103%2FS1062873818120262

B. Publications by other authors worldwide
Zhang L., He W., Clarke J., Ronald K., Phelps A.D.R., Cross A.W., "Microwave Undulator Using a HelicallyCorrugated Waveguide,“ IEEE Trans. on Electron Devices, (2018).
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8493357&isnumber=4358746
Hanna S., “Technological and Regulatory Developments for Electromagnetic Transmission into the Millimeter
Wave and Terahertz Wave Spectrum,” In: Arai K., Bhatia R., Kapoor S. (eds) Proceedings of the Future
Technologies Conference (FTC) 2018. FTC 2018. Advances in Intelligent Systems and Computing, vol. 881(2019). DOI: 10.1007/978-3-030-02683-7_36.
https://link.springer.com/chapter/10.1007%2F978-3-030-02683-7_36
Genoud J., Alberti S., Tran T.M. et al., “Parasitic Oscillations in Smooth-Wall Circular Symmetric Gyrotron
Beam Ducts,” J Infrared Millimeter, and Terahertz Waves, vol. 40, n. 2 (2018) 131–149. DOI:10.1007/s10762018-0548-5.
https://link.springer.com/article/10.1007%2Fs10762-018-0548-5
Liang Y., Du Y., Wang D., Yan L., Tian Q., Chen K., Huang W., Tang Ch., Konoplev I.V., Zhang H., Doucas
G., "Selective excitation and control of coherent terahertz Smith-Purcell radiation by high-intensity periodtunable train of electron micro-bunches," Applied Physics Letters, vol. 113, n. 17 (2018. DOI:10.1063/1.5054583.
https://aip.scitation.org/doi/10.1063/1.5054583
Zhang P., Wang L., Zhang Y., Tang M., Xi Y., Liang S., "The coherent THz Smith-Purcell radiation from a threedimensional open holes array structure,” AIP Advance, vol. 8 (2018) 105031. DOI:10.1063/1.5040791.
https://aip.scitation.org/doi/10.1063/1.5040791
Robert C Wolf et al, “Electron-cyclotron-resonance heating in Wendelstein 7-X: A versatile heating and currentdrive method and a tool for in-depth physics studies,” Plasma Phys. Control. Fusion (2018). DOI:10.1088/13616587/aaeab2.
http://iopscience.iop.org/article/10.1088/1361-6587/aaeab2
Kim S.J., Park J.Y., Lee BS. et al. “Beam Dump Fabrication and Simulation by Using PHITS Code and an
ANSYS Analysis,” J. Korean Phys. Soc., vol. 73, n. 8 (2018) 1115-1117. DOI:10.3938/jkps.73.1115.
https://link.springer.com/article/10.3938/jkps.73.1115
Beaudoin B.L., Ting A., Gold S., Narayan A.H., Fischer R., Karakkad J.A., Nusinovich G.S., Antonsen T.M.,"Experimental studies on radio frequency sources for ionospheric heaters, "Physics of Plasmas, vol. 25, n. 10(2018)103116. DOI:10.1063/1.5052183.
https://aip.scitation.org/doi/10.1063/1.5052183
Vishant A.B., A.K. Sinha, Chandrashekhar, "A Novel Approach for Computation of High-Order Axial Modes ina Gyrotron Resonator," IEEE Transactions on Electron Devices, (2018). DOI: 10.1109/TED.2018.2877843.
https://ieeexplore.ieee.org/document/8525283
Farhang H., Abrishamian M.S., "Investigating the Effectiveness of the Proposed Algorithms to Reduce theSimulation Time of the EBAC FEM Gun Code," IEEE Transactions on Electron Devices, vol. 65, n. 7 (2018)
3005-3011 DOI:10.1109/TED.2018.2830501.
https://ieeexplore.ieee.org/document/8356716
Li R., Ruan C., Zhang H. et al., “Optimization and Improvement of Output Performance in G-Band Extended
Interaction Klystron, J Infrared, Millimeter, and Terahertz Waves, (2018). DOI:10.1007/s10762-018-0546-7.
https://link.springer.com/article/10.1007%2Fs10762-018-0546-7

Bian H.Q., Du C.H., Pan S. et al., “Terahertz Frequency- and Mode-Insensitive Broadband Quasi-optical
Converter Antenna System,” J Infrared Millimeter, and Terahertz Waves, vol. 39, n. 11 (2018) 1065-1078.
DOI:10.1007/s10762-018-0523-1.
https://link.springer.com/article/10.1007%2Fs10762-018-0523-1
Tsun-Hsu Chang, and Kun-Jie Xu, “Gain and bandwidth of the TM-mode gyrotron amplifiers,” Physics ofPlasmas, vol. 25 (2018) 112109. DOI:10.1063/1.5055260.
https://aip.scitation.org/doi/10.1063/1.5055260
Yuvaraj S., Kartikeyan M.V., Thumm M.K., "Design Studies of a 3-MW, Multifrequency (170/204/236 GHz)
DEMO Class Triangular Corrugated Coaxial Cavity Gyrotron," IEEE Trans. on Electron Devices, (2018).
DOI:10.1109/TED.2018.2876870.
https://ieeexplore.ieee.org/document/8532103
ZhaoXiaoyun, FangYong, WangHuajun, TuoXianguo, „Analysis of the effect of field non-uniformity on energy
conversion efficiency in a cyclotron-wave rectifier,"Physics of Plasmas, vl. 25, n. 11 (2018)113104.
DOI:10.1063/1.5053657.
https://aip.scitation.org/doi/abs/10.1063/1.5053657
Liu M., Schamiloglu E., Yurt S.C., Elfrgani A., Fuks M.I., Liu C., "Coherent Cherenkov-cyclotron radiation
excited by an electron beam in a two-spiral metamaterial waveguide," AIP Advances, vol. 8, n. 11 (2018).
DOI:10.1063/1.5049380.
https://aip.scitation.org/doi/full/10.1063/1.5049380
Ryskin N.M., “Development and Modeling of Miniaturized Traveling-Wave Tubes in Millimeter and Sub-THz
Bands,” EPJ Web Conf., vol. 195 (2018) 01014. DOI: 10.1051/epjconf/201819501014.
https://www.epjconferences.org/articles/epjconf/abs/2018/30/epjconf_tera2018_01014/epjconf_tera2018_01014.html
Adilova A.B., Ryskin N.M., “Study of mutual phase locking of two gyrotrons coupled with delay,” EPJ Web
Conf., vol. 195 (2018) 01001. DOI:10.1051/epjconf/201819501001.
https://www.epjconferences.org/articles/epjconf/abs/2018/30/epjconf_tera2018_01001/epjconf_tera2018_01001.html
Bin W., Bruschi A., Fanale F., Francesca M., et al, "Tests and developments of a long-pulse high-power 170 GHz
absorbing matched load," Fusion Engineering and Design (2018). DOI:10.1016/j.fusengdes.2018.11.019.
https://www.sciencedirect.com/science/article/pii/S0920379618307270?via%3Dihub
C. Lau et al., "Circular Corrugated Miter Bend and Gap Losses for Broadband Frequency Applications," IEEE
Trans. on Microwave Theory and Techniques. DOI:10.1109/TMTT.2018.2879808.
https://ieeexplore.ieee.org/abstract/document/8542752
Chen S.H., Chen K.W., Chu K.R., "A comparative study of single-wire and hollow metallic waveguides forterahertz waves," AIP Advances, vol. 8, n. 11 (2018) 115028. DOI:10.1063/1.5055213.
https://aip.scitation.org/doi/10.1063/1.5055213
Z. Duan et al., "Metamaterial-Inspired Vacuum Electron Devices and Accelerators," IEEE Trans. on Electron
Devices, (2018). DOI:10.1109/TED.2018.2878242.
https://ieeexplore.ieee.org/document/8544014
Anderson J.P, Doane J., Grunloh H., BrookmanM., Su D., “Wideband polarizers, switches and waveguide forovermoded corrugated transmission lines,” Fusion Engineering and Design, (2018). DOI:
10.1016/j.fusengdes.2018.11.023.
https://www.sciencedirect.com/science/article/pii/S0920379618307312

Strauss D., AielloG., Bertizzolo., Bruschi A., et al., “Nearing final design of the ITER EC H&CD Upper
Launcher,” Fusion Engineering and Design, (2018). DOI:10.1016/j.fusengdes.2018.11.013.
http://www.sciencedirect.com/science/article/pii/S0920379618307130
Kesari V., Seshadri R., Khare A., Tiwary U.S., Sethi I.K., Singh N., “Magnetic Field Sensitivity in Depressed
Collector for a Millimeter-Wave Gyrotron,” Chapter in: Recent Trends in Communication, Computing, andElectronics, (Springer Singapore, 2019) 53- 58.DOI: 10.1007/978-981-13-2685-1_6.
https://link.springer.com/chapter/10.1007/978-981-13-2685-1_6
Ploskih A.E., Ryskin N.M., Burtsev A.A., Danilushkin A.V., Navrotsky I.A., “Performance Improvement of a
Sub-THz Traveling-Wave Tube by using an Electron Optic System with a Converging Sheet Electron Beam,”Results in Physics, (2018). DOI:10.1016/j.rinp.2018.12.038.
http://www.sciencedirect.com/science/article/pii/S22113797183253
Liu Wenxin, Li Ke, Gao Pengpeng, Zhao Chao, Guo Xin, Zhang Zhaochuan, "Nonlinear theory for beam-wave
interactions of two electron beams with higher order TE20 mode in serpentine waveguide traveling wave
amplifier," Physics of Plasmas, vol. 25, n. 12 (2018) 123106.
https://aip.scitation.org/doi/abs/10.1063/1.5030593
Sawant A., Choi E., "Development of the Full Package of Gyrotron Simulation Code," Journal of the Korean
Physical Society, vol. 73, n. 11 (2018) 1750-1759. DOI:10.3938/jkps.73.1750.
https://link.springer.com/article/10.3938%2Fjkps.73.1750
Mizojiri S, Shimamura K., "Wireless Power Transfer via Subterahertz-Wave," Applied Sciences, vol. 8, n. 12(2018). DOI:10.3390/app8122653.
https://www.mdpi.com/2076-3417/8/12/2653
Garavaglia S., Granucci G., Bruschi A,, Fanale F., et al, “Preliminary conceptual design of the DTT EC heating
system,” Fusion Engineering and Design, (2018). DOI:10.1016/j.fusengdes.2018.12.018.
http://www.sciencedirect.com/science/article/pii/S0920379618307841
Tian Y.Z., Xia D.H., Liu C.H, Wang Z.J., “Test of polarizers for the 105 GHz ECRH system on J-TEXT,” Fusion
Engineering and Design, (2018). DOI:10.1016/j.fusengdes.2018.12.043.
https://www.sciencedirect.com/science/article/pii/S0920379618308081
Sizov F., “Infrared and terahertz in application to biomedicine,” International Journal of Biosensors &Bioelectronics, vol. 4, n. 3 (2018) 134‒136. DOI:10.15406/ijbsbe.2018.04.00114.
https://pdfs.semanticscholar.org/e9fe/74af5d876a631c4146adeb7eb34582a7488c.pdf
Gelfusa M., Simonetto A., Mirizzi F., Peluso E., et al, “Stray millimeter-wave radiation loads on ITER fusedsilica windows,” Fusion Engineering and Design, (2018). DOI:10.1016/j.fusengdes.2018.12.052.
http://www.sciencedirect.com/science/article/pii/S0920379618308172
Xu W., Xu H., Liu F., Hu H., Feng J., "Electromagnetic Compatibility in Electron Cyclotron Resonance Heating
System," IEEE Trans. Plasma Science, (2018). DOI:10.1109/TPS.2018.2885400.
https://ieeexplore.ieee.org/abstract/document/8580567
Suphakul S., Zen H., Kii T., Ohgaki H., “Investigation of Bunch Compressor and Compressed Electron BeamCharacteristics by Coherent Transition Radiation,” Particles, 2 (2019) 32–43. DOI:10.3390/particles2010003.
https://www.mdpi.com/2571-712X/2/1/3
Lu X., Shapiro M., Mastovsky I., Temkin R.J., Conde M., Power J., Shao J., Wisniewski E.E., Jing Ch.,
“Generation of High-Power, Reversed-Cherenkov Wakefield Radiation in a Metamaterial Structure,” Phys. Rev.
Lett., vol. 122, n.1 (2019) 014801. DOI:10.1103/PhysRevLett.122.014801.

https://link.aps.org/doi/10.1103/PhysRevLett.122.014801
Ravera G.L., Ceccuzzi S., Dattoli G., Di Palma E., Doria A., Gallerano G.P., Giovenale E., Mirizzi F., SchettiniG., Spassovsky I., Tuccillo A.A., “Optimization of TE11/TE04 mode converters for the cold test of a 250 GHz
CARM source,” Fusion Engineering and Design, (2019). DOI:10.1016/j.fusengdes.2019.01.069.
http://www.sciencedirect.com/science/article/pii/S0920379619300766
Artem’ev, K.V., Batanov, G.M., Berezhetskaya, N.K. et al., “Discharge in a Subthreshold Microwave Beam as
an Unusual Type of Ionization Wave,” Plasma Phys. Rep., vol. 44: (2018) 1146. DOI:
10.1134/S1063780X18120012.
https://link.springer.com/article/10.1134/S1063780X18120012
Tan K.O., Yang Ch., Weber R.T., Mathies G., Griffin R.G., “Time-optimized pulsed dynamic nuclear
polarization,” Science Advances, vol. 5, n. 1 (2019) eaav6909. DOI: 10.1126/sciadv.aav6909.
http://advances.sciencemag.org/content/5/1/eaav6909.full
Arti, Kumar N., Singh U., Gahlaut V., Bera A., "Inverse Magnetron Injection Gun for Megawatt Power, SubTHz Gyrotron," IEEE Trans. on Plasma Science, (2019). DOI: 10.1109/TPS.2019.2890876.
https://ieeexplore.ieee.org/document/8621616
Yan R., Wang D., Li H., Mu M., Lian Y., Luo Y, "Design of Collectors for High Average/Continuous-Wave
Power Gyro-Devices,"IEEE Trans. on Electron Devices, (2019). DOI:10.1109/TED.2018.2889722.
https://ieeexplore.ieee.org/document/8613878
Wang X., Xue Q., Zhang S., Zhao G., Liu G., Zhao D., “Influence of magnetic field taper on second harmonic
394GHz gyrotron oscillator,” AIP Advances, vol. 9, n. 1 (2019) 015126. DOI: 10.1063/1.5083101.
https://aip.scitation.org/doi/10.1063/1.5083101#
Zhang L., He W., Clarke J., Ronald K., Phelps A. D. R., Cross A., “Systematic study of a corrugated waveguideas a microwave undulator,” Journal of Synchrotron Radiation, vol. 26 (2019)11-17. DOI:10.1107/
S1600577518014297.
http://scripts.iucr.org/cgi-bin/paper?S1600577518014297
Hou Sh., Yu Sh., Li H., “Numerical research on a 4 MW 170 GHz coaxial gyrotron with a double electron beam,”
Physics of Plasmas, vol. 26 (2019) 013110. DOI:10.1063/1.5053637.
https://aip.scitation.org/doi/abs/10.1063/1.5053637
Zhang P., Wang L., Zhang Y., Aimidula A., Tang M., "Intensive vertical orientation Smith–Purcell radiationfrom the 2D well-array metasurface," Opt. Express, vol. 27 (2019) 3952-3962. DOI: 10.1364/OE.27.003952.
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-4-3952

C. Patents
Methods and apparatus for adjusting a wavelength electromagnetic waves
Inventor: Paul Shala Henry, Giovanni Vannucci, Thomas M. Willis, III, Shikik Johnson, Robert Bennett,
Farhad Barzegar, Irwin Gerszberg, Donald J. Barnickel
US Patent: US10096883B2
Date of publication: 2018-06-07
https://patents.google.com/patent/US20180159197A1/en
Self-referencing frequency comb based on high-order sideband generation
Inventors: Mark Sherwin, Hunter Banks, Darren Valovcin
Patent Application Publication: No. :US 2018 / 0301868 A1

Publication date: 18 Oct 2018https://tinyurl.com/y96s49fk
Extended interaction device comprising coaxial resonant cavities and multiple electron beams
Inventors: Yong YIN, Lin MENG, Bin WANG, Hailong LI
Patent Application Publication: No.: US 2018 / 0301311 A1
https://tinyurl.com/y8hpppad
Slow-wave structure for a traveling-wave tube
Inventors: G.V. Torgashov, N.M., Ryskin, D. Shalaev
Russian patent: RU 183912
Publication date: 9 Oct 2018https://www.researchgate.net/publication/328702502_Slow-wave_structure_for_a_traveling-wave_tube
Up and down conversion systems for production of emitted light from various energy sources including
radio frequency, microwave energy and magnetic induction sources for upconversion
Inventors: Frederic A. Bourke, Jr., Zakaryae Fathi, Ian Nicholas Stanton, Michael J. Therien, Paul RathStauffer, Paolo MacCarini, Katherine Sarah Hansen, Diane Renee Fels, Cory Robert Wyatt
US Patent Application: US20180317307A1
Publication date: 1 Nov 2018https://patents.google.com/patent/US20180317307A1/en
Method and apparatus of communication utilizing waveguide and wireless devices
Inventors: David M. Britz, John W. MacNeill, David DeVincentis, Robert Bennett, Paul Shala Henry, Irwin
Gerszberg, Farhad Barzegar, Thomas M. Willis, III, Donald J. Barnickel
US Application US20180219579A1
Publication date: 23 Oct 2018https://patents.google.com/patent/US20180219579A1/en
Microwave Electrothermal Thruster Adapted for In-Space Electrothermal Propulsion
Inventors: Rohan M. Ganapathy, Bellary ( IN )Patent application: US 2018 / 0327118 A1
Publication date: 15 Nov 2018https://patents.google.com/patent/WO2017085746A1/en
Slow Wave Circuit and Travelling Wave Tube
Inventors: Norio Masuda, Tokyo (JP) , Takashi Nakano, Tokyo (JP)Patent application: US 2018 / 0337016 A1
Publication date: 22 Nov 2018https://tinyurl.com/y8x9b66j
Magnets for Magnetic Resonance Applications
United States Patent Application: 20180340994
Inventors: Ibragimova Olena (Ottweiler-Fuerth, DE), Ibragimov Ilgiz (Ottweiler-Fuerth, DE)
Publication date: 29 Nov 2018
http://www.freepatentsonline.com/y2018/0340994.html
Real-Time Methods for Magnetic Resonance Spectra Acquisition
United States Patent Application 20180340997
Inventors: Ibragimova Olena (Ottweiler-Fuerth, DE), Ibragimov Ilgiz (Ottweiler-Fuerth, DE)
Publication date: 29 Nov 2018
http://www.freepatentsonline.com/y2018/0340997.html
Apparatus and methods for launching guided waves via an antenna

United States Patent US10135147B2
Inventors: Paul Shala Henry, Robert Bennett, Farhad Barzegar, Irwin Gerszberg, Donald J. Barnickel,
Thomas M. Willis, III
Publication date: 20 Nov 2018https://patents.google.com/patent/US20180108998A1/en
Accelerating cavity and accelerator
United States Patent Application US20190014653A1
Inventors: Mitsuhiro Yoshida, Daisuke Satoh, Nobuyuki Shigeoka, Sadao Miura
Publication date: 10 Jan 2019https://patents.google.com/patent/US20190014653A1/en
Relativistic magnetron using a virtual cathode
United States Patent US10192709B2
Inventors: Edl Schamiloglu, Mikhail I. Fuks
Publication date: 29 Jan 2019https://patents.google.com/patent/US10192709B2/en

NEW BOOKSFishman R.S., Fernandez-Baca J.A., Room T., Spin-Wave Theory and its Applications to Neutron Scatteringand THz Spectroscopy, (Morgan & Claypool Publishers, 2018).ISSN 978-1-64327-114-9. DOI:10.1088/978-164327-114-9.
http://iopscience.iop.org/book/978-1-64327-114-9.pdf
Jean-Louis Coutaz, Frederic Garet, Vincent P. Wallace, Principles of Terahertz Time-Domain Spectroscopy:
An Introductory Textbook, (CRC Press, Dec 3, 2018) 622 pages. ISBN 1351356364, 9781351356367.
https://www.crcpress.com/Principles-of-Terahertz-Time-Domain-Spectroscopy/Coutaz-GaretWallace/p/book/9789814774567
Zhang C, Zhang XC, Tani M., Infrared, Millimeter-Wave, and Terahertz Technologies V. InProc. of SPIE Vol
2018 Nov (Vol. 10826, pp. 1082601-1).
https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10826/1082601/Front-Matter-Volume10826/10.1117/12.2522342.full?SSO=1
Marcus Seidel, A New Generation of High-Power, Waveform Controlled, Few-Cycle Light Sources, Springer
Theses, 2019). (DOI:10.1007/978-3-030-10791-8. Print ISBN 978-3-030-10790-1 Online ISBN 978-3-03010791-8.
https://link.springer.com/book/10.1007/978-3-030-10791-8

NEWS
57th Annual Meeting of the Electronic Spin Science Association
The 57th Annual Meetings of the Society of Electron Spin Science and Technology (SEST2018) was held at theConference Hall, Hokkaido University from 1st to 3rd October 2018.

Assistant Professor Yuya Ishikawa has been awarded by the Excellence Presentation Award for your work on thedevelopment of Ultra-Low-Temperature ESR / NMR Measurement System for Millimeter Wave Band.

Source: The Society of Electron Spin Science and Technology (SEST)