Lebedev physical institute radiation complex – current status and new concepts
Multipurpose radiation complex is the result of long- term permanent development of new instrumentation at the Lebedev Physical Institute. This is stand-alone large facility designed for fundamental and applied research that had been started from the high current racetrack microtron project in the m...
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| Date: | 2001 |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2001
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| Cite this: | Lebedev physical institute radiation complex – current status and new concepts / A.V. Agafonov, V.M. Alekseev, A.I. Bukin, V.P. Busygin, A.V. Koltsov, V.G. Kurakin, A.N. Lebedev, E.I. Tamm, P.V. Kurakin // Вопросы атомной науки и техники. — 2001. — № 3. — С. 9-11. — Бібліогр.: 6 назв. — рос. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859623760178446336 |
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| author | Agafonov, A.V. Alekseev, V.M. Bukin, A.I. Busygin, V.P. Koltsov, A.V. Kurakin, V.G. Lebedev, A.N. Tamm, E.I. Kurakin, P.V. |
| author_facet | Agafonov, A.V. Alekseev, V.M. Bukin, A.I. Busygin, V.P. Koltsov, A.V. Kurakin, V.G. Lebedev, A.N. Tamm, E.I. Kurakin, P.V. |
| citation_txt | Lebedev physical institute radiation complex – current status and new concepts / A.V. Agafonov, V.M. Alekseev, A.I. Bukin, V.P. Busygin, A.V. Koltsov, V.G. Kurakin, A.N. Lebedev, E.I. Tamm, P.V. Kurakin // Вопросы атомной науки и техники. — 2001. — № 3. — С. 9-11. — Бібліогр.: 6 назв. — рос. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | Multipurpose radiation complex is the result of long- term permanent development of new instrumentation at the Lebedev Physical Institute. This is stand-alone large facility designed for fundamental and applied research that had been started from the high current racetrack microtron project in the mid of seventies and has been completed by commissioning of far infrared FEL nowadays. Current status of the radiation complex including research as well as linac and FEL performance improvement is discussed in paper presented followed by new ideas in further facility development and application.
|
| first_indexed | 2025-11-29T08:38:57Z |
| format | Article |
| fulltext |
LEBEDEV PHYSICAL INSTITUTE RADIATION COMPLEX –
CURRENT STATUS AND NEW CONCEPTS
A.V. Agafonov, V.M. Alekseev, A.I. Bukin, V.P. Busygin, A.V. Koltsov,
V.G. Kurakin, A.N. Lebedev, E.I. Tamm, P.V. Kurakin1
Lebedev Physical Institute, Moscow, Russia
1Keldysh Institute of Applied Mathematics, Moscow, Russia
Multipurpose radiation complex is the result of long- term permanent development of new instrumentation at the
Lebedev Physical Institute. This is stand-alone large facility designed for fundamental and applied research that had
been started from the high current racetrack microtron project in the mid of seventies and has been completed by
commissioning of far infrared FEL nowadays. Current status of the radiation complex including research as well as
linac and FEL performance improvement is discussed in paper presented followed by new ideas in further facility
development and application.
PACS numbers: 29.17.+w, 41.60.Cr
1 INTRODUCTION
Free electron lasers (FEL) supplement successfully
classical lasers in short as well as in long wave ranges
when used for exploration of radiation with physical
matter and biological objects. In addition, such property
of FEL radiation as temporal structure synchronized
with a beam structure makes it possible to carry out
multiphoton experiments. In the simplest case the object
under investigation is influenced both by FEL radiation
and RF power used for linac structure excitation, and
one studies the sample reaction in dependence on the
phase shift, intensity, etc of two probes. Far infrared
FEL excited by the electron beam from the RF linac has
been commissioned successfully, and stimulated radia-
tion has been detected. We consider this FEL as the first
stage of multipurpose radiation complex to be used for
solids exploration mainly with coherent electromagnetic
radiation in the wave range 10 – 500 microns at the
Lebedev Physical Institute. Thus, next stage has been
started with the FEL commissioning, and this stage will
be used for detailed FEL investigation as a device for
physical research as well as for first experiment prepara-
tion. Following is the facility description as well as new
problems discussion we are working at.
2 FAR INFRARED FEL FACILITY
Fig.1 represents the schematic of far infrared FEL
together with the accelerator-driver and electron beam-
line.
1
2
34
5
54 6758910
9
9
9 14
11
11 12
8
10
13
15
7
16
Fig. 1. Schematic of the far infrared FEL. 1- electron gun, 2 – inflector, 3 – linac, 4 – quadruple doublet,
5 – correcting coil, 6 – vacuum valve, 7 – current monitor, 8 – luminescent screen, 9 – bending magnet,
10 – Faraday cup, 11 – mirror container, 12 – observation mirror driving system, 13 – luminescent
screen driving system, 14 – multiwire monitor for magnetic spectrometer, 15 – electromagnetic undula-
tor, 16 – magnetic spectrometer.
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. №3.
Серия: Ядерно-физические исследования (38), с. 9-11.
9
The layout of the radiating part one can see from the
photo in Fig. 2. A driving electron beam is produced in
the RF linac formed by the accelerating structure on the
basis of a disk-loaded waveguide and an injecting sys-
tem consisting of a high gradient RF cavity and a low
voltage electron gun. Such a scheme makes it possible
to produce short bunches at the accelerator exit with
narrow energy spread that is quite necessary for appro-
priate FEL performance [1]. The beam from the linac
exit is delivered into the FEL interaction region by a
beam line formed by focusing quadruple lenses and cor-
rection coils, a monitoring and injecting system. The lat-
ter consists of three bending magnets and provides
achromatic transportation of electron bunches onto the
undulator axis while the former allows keeping the in-
jection process under control. A magnetic spectrometer
at the entrance of the beam line serves to tune the accel-
erator to the narrowest beam energy spread. This can be
achieved with the appropriate RF phase shift adjustment
between the disk-loaded waveguide and RF cavity of
the injection system.
Fig. 2. Layout of the far infrared FEL facility.
A helical undulator [2] and an open resonator com-
pose the laser itself. The driving electron beam interacts
with cavity optical mode due to transverse motion in the
interaction region induced by the undulator magnetic
field. This interaction may result in beam self-bunching
and this process results in turn in coherent radiation. To
induce instability the described gain per path has to ex-
ceed the total losses inside the cavity, and this imposes
serious limitation on the electron beam quality as well
on the cavity and undulator parameters specification.
Table 1 collects the main parameters of our FEL.
Table 1. Far infrared FEL parameters
Wavelength range (µm) 80 - 160
FEL radiation power (expected) 60 kW
Pulse duration (µs) 5 - 6
Micro pulse duration 30 ps
Electron beam energy (MeV) 6 - 8
Energy spread at FEL entrance (%) 1.5
Gain per path (at peak current 10 A) 20
Optical cavity length 165 cm
Mirror diameter 2.8 cm
Mirror curvature radius 1.8 m
Waste of laser mode 5mm
Accelerator wavelength 16.5 cm
Accelerator repetition rate (Hz) 0.1 - 5
Vertical beam emittance 3⋅π⋅mm⋅mrad
Horizontal beam emittance 7⋅π⋅mm⋅mrad
Undulator period 3.2 cm
Number of turns 35
Beam pipe aperture 2.7 cm
Maximum current through winding 45 kA
Repetition rate at maximum current 0.05 Hz
Undulator parameter 0 – 1.4
Linac and laser elements adjusting as well as thor-
ough beam dynamics investigation had followed FEL
facility assembling. A semiconductor laser diagnostic
alignment system as well as a FEL adjustment and beam
diagnostic system were used to align the undulator and
mirrors. We refer to [3,4] for the details.
We have 0.5 A in beam pulse at accelerator exit and
350 mA at undulator exit as typical beam current values
during the FEL generation experiment. Microwave radi-
ation from FEL is gathered by the parabolic mirror with
the focus at the entrance of the copper tube (waveguide)
that transmits it to the sensor of the optic-to-acoustic
converter that operates in a pulse mode [2]. We had
fixed FEL generation at the end of 2000 after the long
step-by-step resonator length adjustment. It was very
unstable. Comprehensive analysis was made and FEL
facility system performance improved to bring driving
beam parameters to a much more stable level. We ex-
pect to obtain a much more stable generation in the new
experimental run at the end of 2001.
Perhaps, the computer based monitoring and control
system with adjustable user interface is after FEL facili-
ty the most remarkable result of long-term development
of novel experimental technique at the Lebedev Physi-
cal Institute [5]. The system mentioned consists of hard-
and software for physical data acquisition and physical
equipment control in real time scale with the interface
that user can adjust at the level of executability. Digit-
to-analog converter and multichannel waveform digitiz-
er are base hardware elements while the software is
based on a novel visual-programming concept. Borland
C++ Builder has been used for code development, and
the concept of interface building is the same that soft-
ware mentioned uses. The essential difference is that the
form filling with the necessary components is moved to
the executable level. Components used for physical data
representation are: numeric indicator, plot, histogram
and spectrum. These can be adjusted during the experi-
ment and the procedure does not require compiling and
linking. This is crucial for our approach since often the
most dangerous errors occur after correction of the code
written some time before. There are also the compo-
nents that are responsible for data processing before
their visualization as well as for animation of visualized
data. The latter means that any time dependent compo-
nent used for data representation may be played back in
slower time after triggering by so called external selec-
tion pulse. The adjustment of interface is achieved in a
manner similar to the Borland technology that is due to
adjustment of appropriate properties in a property editor
and the possibility of movement and sizing of the com-
ponents on the top of the form. Network component is
available too, and this clears the way for precise remote
10
measurements – data can be digitized in the hot zone
and transmitted to the main console for on-line process-
ing and visualization. There is a possibility of importing
the picture onto the form, and this we use for creation of
an appropriate mnemonic scheme on the computer dis-
play.
Fig. 3 is the cut from the used interface in a design
mode, used to fill in the computer display with neces-
sary devices before real measurements. This is the code
editor to fix conversion formulae and directives that
may be desired before data visualization at the measure-
ment stage.
Fig. 3. Code editor – the element of processing the com-
ponent of adjustable user interface.
3 NEXT STEPS – EXPERIMENT AND NOV-
EL TECHNIQUES
Comprehensive FEL exploration and first experi-
ment preparation are next natural steps of our work. We
are going to start from the two-photon experiment on
resonance properties of high-Tc superconducting films.
A film will be placed in a gap inthe inner conductor of
the stripline. The design allows exposing the film to
FEL microwave radiation. At the same time the stripline
is the part of the microwave circuit, the rf power syn-
chronized with the linac rf power being the second wave
that interacts with the film.
Two ways of moving to shorter wavelengths of co-
herent radiation are foreseen. The first one is the use of
driving electron beam from the next racetrack orbits – in
our configuration one can reach as short wavelength as
10 microns. It seems to be very attractive to build an
electron storage ring with the maximum energy up to
100 MeV with the existing racetrack used as an injector.
In this case one can cover the bandwidth of 1-100 mi-
crons with the FEL installed in the strait section of such
a storage ring. The advantages of the latter case are the
cw mode of operation and low level of background of
any kind.
Novel FEL elements and new undulator schemes, in
particular, are among those things that are in the field of
our interest. We suggest two electromagnetic undulators
that can be made of a commercial high-temperature su-
perconductor cable produced in Russia. The first one is
a usual electromagnetic undulator with the ferromagnet-
ic core and superconducting winding. The industrial ca-
ble allows reaching the current density up to 100 A/mm2
thus allowing to reduce considerably the coil cross- sec-
tion area.
Another attractive design using the flat cable is de-
scribed in details in our paper [6]. The undulator is
formed by two corrugated strips – the second one is the
translation of the first strip in the direction of the x-axis
(Fig. 4). This scheme is attractive from many view-
points and may be performed in normal conducting ver-
sion as well as from the superconducting cable.
Fig. 4. Layout of planar electromagnetic undulator
scheme. One half is shown.
4 CONCLUSION
Novel instrumentation for fundamental and applied
research has been created at the Lebedev Physical Insti-
tute. This is the main result of the intensive work of
many peoples from different laboratories of our Institute
and other organizations. Not everything is mentioned in
the current paper, separate publications in nearest future
will be concerned to specific questions.
The work in part has been made in the frame of the
Federal Program “Microwave physics”.
REFERENCES
1. K.A.Belovintsev, A.I.Karev and V.G.Kurakin. The
Lebedev Physical Institute Race-Track Microtron //
Nuclear Instruments and Methods. 1987. A261,
pp. 36-38.
2. A.I.Bukin, E.B.Gaskevich, V.G.Kurakin and
O.V.Savushkin. The experimental study of helical
undulator // Trudy FIAN, 1993, vol. 214,
pp. 155-163 (in Russian).
3. A.V.Agafonov, A.I.Bukin, A.V.Koltsov, V.G.Ku-
rakin, A.N.Lebedev. Current Status of the Lebedev
Physical Institute Far Infrared Free Electron Laser
// Problem of Atomic Science and Technology. Is-
sue: Nuclear-Physics Research (35). 1999, # 4, p.
3-5.
4. A.V.Agafonov, A.I.Bukin, A.V.Koltsov, V.G.Kura-
kin, A.N.Lebedev. Far Infrared FEL Commission-
ing at the Lebedev Physical Institute // Proceedings
of 7th European Particle Accelerator Conference,
Vienna, 26 - 30 June 2000, p. 749-751.
5. V.G.Kurakin, V.P.Busygin, A.V.Koltsov, Ad-
justable Computer Interface for Measurements and
Control // Ibid, p. 1847-1849.
6. V.G.Kurakin, A.I.Bukin, Field Distribution in Pla-
nar Electromagnetic Wiggler // Ibid, p. 746-748.
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. №3.
Серия: Ядерно-физические исследования (38), с. 11-11.
11
1 INTRODUCTION
2 Far Infrared FEL Facility
|
| id | nasplib_isofts_kiev_ua-123456789-79213 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-11-29T08:38:57Z |
| publishDate | 2001 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Agafonov, A.V. Alekseev, V.M. Bukin, A.I. Busygin, V.P. Koltsov, A.V. Kurakin, V.G. Lebedev, A.N. Tamm, E.I. Kurakin, P.V. 2015-03-29T18:40:26Z 2015-03-29T18:40:26Z 2001 Lebedev physical institute radiation complex – current status and new concepts / A.V. Agafonov, V.M. Alekseev, A.I. Bukin, V.P. Busygin, A.V. Koltsov, V.G. Kurakin, A.N. Lebedev, E.I. Tamm, P.V. Kurakin // Вопросы атомной науки и техники. — 2001. — № 3. — С. 9-11. — Бібліогр.: 6 назв. — рос. 1562-6016 PACS numbers: 29.17.+w, 41.60.Cr https://nasplib.isofts.kiev.ua/handle/123456789/79213 Multipurpose radiation complex is the result of long- term permanent development of new instrumentation at the Lebedev Physical Institute. This is stand-alone large facility designed for fundamental and applied research that had been started from the high current racetrack microtron project in the mid of seventies and has been completed by commissioning of far infrared FEL nowadays. Current status of the radiation complex including research as well as linac and FEL performance improvement is discussed in paper presented followed by new ideas in further facility development and application. The work in part has been made in the frame of the Federal Program “Microwave physics”. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Lebedev physical institute radiation complex – current status and new concepts Излучательный комплекс ФИАН – современное состояние и новые концепции Article published earlier |
| spellingShingle | Lebedev physical institute radiation complex – current status and new concepts Agafonov, A.V. Alekseev, V.M. Bukin, A.I. Busygin, V.P. Koltsov, A.V. Kurakin, V.G. Lebedev, A.N. Tamm, E.I. Kurakin, P.V. |
| title | Lebedev physical institute radiation complex – current status and new concepts |
| title_alt | Излучательный комплекс ФИАН – современное состояние и новые концепции |
| title_full | Lebedev physical institute radiation complex – current status and new concepts |
| title_fullStr | Lebedev physical institute radiation complex – current status and new concepts |
| title_full_unstemmed | Lebedev physical institute radiation complex – current status and new concepts |
| title_short | Lebedev physical institute radiation complex – current status and new concepts |
| title_sort | lebedev physical institute radiation complex – current status and new concepts |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/79213 |
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