FEL applications

Paper Title Page
MOPPH027 Status of the KAERI THz FEL for the Application on Security Inspection
  • P. Ahn, H. J. Cha, B. C. Lee, J. Mun, S. H. Park, Y. U. Jeong
    KAERI, Daejon
  • G. M. Kazakevich
    Fermilab, Batavia, Illinois
  Terahertz (THz) technology has been considered as a new tool for security inspection due to its safe energy range to human irradiation, foot-print spectral characteristics for most chemicals and bio-materials, and relatively high spatial resolution for imaging. One of the main tasks in the THz inspection technology is to develop a high power and compact source to realize a real-time imaging. We have developed a compact terahertz (THz) free electron laser (FEL). The FEL operates in the wavelength range of 100–1200 micrometers, which corresponds to 0.3–3 THz. THz radiation from the FEL shows much higher power of 100 W when compared to the power level, < 100 mW, of the table-top sources by conventional lasers. The THz FEL beam shows a good performance in pulse-energy stability, polarization, spectrum and spatial distribution. We report the experimental studies of the transmission and reflection-type scanning imaging of baggage and a window dummy. The required power level of the THz sources is estimated for the practical applications of the inspection imaging.  
MOPPH028 On NMR probing of the kinetics of a free-electron laser-induced chemical exchange 81
  • S. P. Babailov
    Nikolaev IIC, Novosibirsk
  Determination of the quantum yields of photochemical reactions (in particular, molecular photoisomerization reactions) is an efficient application of NMR spectroscopy*,**. We are proposed a combined approach for study the kinetics of photo-induced chemical exchange (PICE) reactions (see Scheme), which involves a free-electron laser (FEL) and NMR spectroscopy**. Scheme hv A↔B Continuous and pulse IR-irradiation of the chemical system in the presence of PICE can be achieved using FEL. Based on the analytical equations derived in the work we consider the time-dependent dynamics of variation of the instant NMR line shape for two-site chemical exchange. If one induce an abrupt increase in the rate constant of chemical exchange (for example, by quickly heating the system or PICE), then the NMR line shape will change with time, ultimately reaching another new steady state. Our calculations show that there are beats and oscillations (on the NMR line shape) damped with time. The information about the time-dependent instant line shapes provides possibility to predict the real kinetics of PICE. Prospective objects are molecular conformers and spin isomers. So, FEL can be used in the setup for PICE studies in combination with a NMR spectrometer.

* S. P. Babailov, E. M. Glebov, et al., Concepts in Magn. Reson., 2006, 8, 571. ** S. P. Babailov, Russ. Chem. Bull., Int. Ed., 2006, 10, 1631.

MOPPH029 Nondestructive Transfer of Complex Molecular Systems into Aerosol Phase by Means of Terahertz Irradiation of Free Electron Laser
  • T. N. Goryachkovskaya, S. E. Peltek
    ICG SB RAS, Novosibirsk
  • S. B. Malyshkin, A. K. Petrov, M. B. Taraban, A. S. Kozlov
    ICKC SB RAS, Novosibirsk
  • V. M. Popik, M. A. Scheglov
    BINP SB RAS, Novosibirsk
  Original investigations of ablation of various substances under the action of submillimeter radiation of the free electron laser (FEL) developed and built at Budker Institute of Nuclear Physics were carried out at the Chemical and Biological user station of the Siberian Center for Photochemical Research. It was shown that ablation can be nondestructive. In order to determine the size distribution of aerosol products, we used the Diffusion Aerosol Spectrometer (DSA) developed at the ICKC SB RAS* and sampling for examination with electron microscope. The arrangement of experiments and equipment involved allowed us to determine the disperse composition of irradiation products within particle size range 3nm – 10mkm. At the present moment we have classified the aerosol products of ablation of the following substances: Crustal minerals, Fullerene-like complexes based on molybdenum; Polymers with different molecular masses, Biological macromolecules**. The most impressive results are obtained under ablation of biological macromolecules. In order to reveal whether the enzymatic activity of ablation products is conserved, we carried out a test for histochemical coloring of the collected aerosol of horse radish peroxidase. The test showed that this complicated enzyme remained active after ablation. We believe that this result is extremely important for biotechnology.

* A. N. Ankilov et al. Atmospheric Res., 2002, 62, 209-237.** A. K. Petrov et al. Nuclear Inst. and Methods in Physics Res., 2007, 575, 68-71.

MOPPH030 Terahertz Imaging and Radioscopy with 160x120 Microbolometer 90 fps Camera 83
  • A. L. Aseev, M. A. Dem'yanenko, D. G. Esaev, I. V. Marchishin
    ISP, Novosibirsk
  • G. N. Kulipanov, N. Vinokurov, B. A. Knyazev
    BINP SB RAS, Novosibirsk
  Uncooled micromolometer camera for IR and THz high-speed imaging has been developed. The 160x120 focal plane array consists of resistive vanadium oxide elements on a silicon nitride bridge. The element size is 48x48 micron at 51 micron array period. We describe device fabrication process and focal plane array operational characteristics. The camera was used as a recorder in quasi-optical systems with Novosibirsk terahertz free electron laser as a radiation source. Radioscopy of the objects, which are of interest for biology and security applications, has been demonstrated. The recording rate up to 90 frames per second has been obtained.  
MOPPH031 Spectroscopy and Spectrally Resolved Radioscopy of Biological Substances Using Terahertz Free Electron Laser Radiation 86
  • V. V. Gerasimov
    NSU, Novosibirsk
  • A. M. Gonchar
    ICG SB RAS, Novosibirsk
  • B. A. Knyazev
    BINP SB RAS, Novosibirsk
  High average power and monochromacity of terahertz Novosibirsk free electron laser are favorable for the development of time and space resolved spectroscopic and radioscopic techniques for study of highly absorbing substances, in particular, biological ones. To study highly absorbing objects we applied a homemade attenuated total reflection spectrometer, which enables operation in both conventional and imaging mode. By measuring the reflection coefficients for p- and s-polarized radiation, the real (n) and imaginary (k) parts of refractive index can be derived. Using a microbolometer matrix (see the paper by Esaev et al. at this conference), imaging radioscopy of the samples containing amino acids and DNA had been performed. The methods developed were applied also for examination of bones of intact and senescence-accelerated mice that, probably, would lead to study osteoporosis development.  
MOPPH032 Development of Metal Mesh Based Quasi-optical Selective Components and Their Application in High-power Experiments at Novosibirsk Terahertz FEL 89
  • B. G. Goldenberg, P. V. Kalinin, V. V. Kubarev, N. Vinokurov, S. A. Kuznetsov
    BINP SB RAS, Novosibirsk
  Successful realization of terahertz research programs at the Novosibirsk FEL-facility requires detailed development, designing and optimization of passive quasi-optical selective components, intended for polarization and frequency gating of powerful THz-beams of NovoFEL radiation. Along with desired selective characteristics such components should be capable of operating over a long period of time under high-power load conditions (a few hundred Watts of average incident radiation power) without noticeable degradation of their properties. It admits to employ in selective components only low absorbing and thermostable materials, such as high conductivity metals and special types of polymers. This report is devoted to development of metal mesh based selective structures, such as polarizing beamsplitters (attenuators) and different frequency filters, and their application in high-power THz-experiments. Possibilities and prospects of two main production technologies are discussed: 1) conventional photolithography destined for manufacturing thin metal structures deposited on low-absorbing thermostable polymer films; 2) LIGA-technique intended for producing thick substrate-free metal structures.  
MOPPH033 Diffraction Optical Elements and Optical Systems with a High Power Monochromatic Terahertz Source 93
  • H. J. Cha, Y. U. Jeong
    KAERI, Daejon
  • V. S. Cherkassky, L. A. Merzhievsky, S. A. Zhigach
    NSU, Novosibirsk
  • A. V. Fanova, B. A. Knyazev, G. N. Kulipanov, N. Vinokurov, I. A. Polskikh
    BINP SB RAS, Novosibirsk
  We have developed reflective diffraction optical elements (DOE) for focusing radiation of terahertz free electron lasers (FEL). Metal-dielectric Fresnel zone plates and metallic kinoform "lenses" were fabricated and tested using FEL radiation. A microbolometer camera (see the paper by Esaev et al. at this conference) sensitive to THz radiation had been applied for recording both terahertz beam caustic and terahertz images. Diffraction efficiency of a kinoform lens appears to be about unity. Quality of images obtained with the kinoform lens was studied. The lens was used as a key element for a Toepler optical system, which were used for studying condense matter non-uniformities and deformations. The experiments were performed at Novosibirsk and KAERI FELs.  
MOPPH034 Diagnostics of an Electron Beam using Coherent Cherenkov Radiation 95
  • R. Tikhoplav
    UCLA, Los Angeles, California
  A comparison of coherent Cherenkov and transition radiations as a diagnostic tool for longitudinal distribution of an electron beam is studied in this paper. Two methods will be used for the 7th harmonic bunching experiment at Neptune linear accelerator facility at UCLA. Coherent Cherenkov radiation is produced in an aerogel with an index of refraction close to unity.  
MOPPH073 Thermal and Non-thermal Laser Cutting Utilizing Advanced Industrial Lasers and ERL-FELs 175
  • E. J. Minehara
    JAEA/FEL, Ibaraki-ken
  The JAEA and JLAB energy-recovery free-electron lasers (ERL-FEL) have successfully demonstrated capabilities of a few hundreds fs ultra-fast pulse lasing, 6-9% high conversion efficiency, one GW high peak power, a few kW average power, and wide tunability of infrared wavelength regions. Utilizing the high average and high peak power lasing and energy-recovery linac (ERL) technology, we could realize a more powerful and more efficient FEL than 20kW and 25%, respectively, for nuclear industry, pharmacy, medical, defense, shipbuilding, semiconductor industry, chemical industries, environmental sciences, space-debris cleaning, power beaming and so on very near future. We have performed their thermal and non-thermal cutting and machining experiments and characterized their resultant effects. In order to compare some characteristic differences of thermal and non-thermal laser cutting utilizing advanced industrial laser like fiber, and water-guided ones and the ERL-FELs, we have performed some cutting trials of them. In the presentation, we plan to discuss these differences and how to apply all the lasers to the above applications in the fields.  
THBAU01 Research Highlights from FLASH 499
  • J. Feldhaus, R. Treusch
    DESY, Hamburg
  The Free electron LASer in Hamburg (FLASH) has started regular user operation in summer 2005, providing XUV radiation pulses with pulse energies in the 10 - 100 μJ range and pulse durations of 10 - 50 fs. The science programme at FLASH covers a broad range of novel applications including fundamental studies on atoms, ions, molecules and clusters, creation and characterisation of warm dense matter, diffraction imaging of nanoparticles, spectroscopy of bulk solids and surfaces, investigation of surface reactions and spin dynamics, and the development of advanced photon diagnostics and experimental techniques. So far, 16 science projects have been pursued involving approximately 200 scientists from 11 countries. Some of the research highlights will be presented.  
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THBAU02 FELICE, the Free Electron Laser for Intra-Cavity Eperiments
  • B. Redlich, A. F.G. van der Meer
    FOM Rijnhuizen, Nieuwegein
  We present the status and first results of the commissioning of the new beam line FELICE, an extension of the IR User Facility FELIX. The primary purpose of this beam line is to enhance the capabilities of the facility for different types of action spectroscopy of (bio)molecules, ions, clusters and complexes in the gas-phase. FELs such as FELIX are particularly suited for this type of research and the majority of the beam time delivered is nowadays devoted to it. Despite the large number of successful experiments, it soon became clear that for certain experiments even the output of FELIX is not sufficient, especially in the FIR. As the absorption cross sections of the gas samples are inherently low, a very significant boost is possible by making use of the intra-cavity power. FELICE is designed to cover the wavelength range from 3 to 100 microns at a micropulse repetition rate of 1 GHz. It runs interleaved with FELIX at a macropulse repetition rate of up to 10 Hz. The 4-mirror resonator, extending through the radiation shielding, provides an additional focus at either one of two experimental setups: a versatile molecular beam machine and an FTICR ion trap. For the wavelength range above 35 microns, the resonator will be equipped with an insertable, partial waveguide. At this moment, an intermediate stage has been reached in which FELICE can operate in the 6–35 micron range.  
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THBAU03 FEL Irradiation Use for the Biochip Production Standardization
  • T. N. Goryachkovskaya, T. N. Kusnetsova, V. A. Mordvinov, S. E. Peltek
    ICG SB RAS, Novosibirsk
  • A. S. Kozlov, S. B. Malyshkin, A. K. Petrov
    ICKC SB RAS, Novosibirsk
  • V. M. Popik, M. A. Scheglov
    BINP SB RAS, Novosibirsk
  The teraherz emission of the Budker INP Free electron laser was applied to the development of the scientific base for the biochip production standardization. The complementary pairings of hydrogen bonds of DNA nucleotides are the base of biochip applications. The technique is based on the method of soft nondestruction ablation developed by authors, which means the transfer of molecules to aerosol phase form solid substrate under action of the teraherz emission. The teraherz emission excites nonvalency of molecular bonds. Ablation of horseradish peroxidase biomoleculs was carried out and nondestruction of biomelecules was verified by using of an aerosol spectrometer and an electrophoresis in polyacrylamide gel. By hystochemical staining technique there was verified that peroxidase has retained its enzymatic activity. The molecular design of model biochip oligonucleotides and polymerase chain reaction analysis of ablation product were developed. The prototype of two different biochips on high resistance silicon substrate were manufactured. Requirements to the coating and immobilization of oligonucleotide probes on silicon substrate were developed. The first experiment on nondestruction ablation under teraherz emission of oligonucleotides from model biochip was achieved.  
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THBAU04 Millimeter Waves Sensing Behind Walls - Feasibility Study with FEL Radiation 501
  • M. Einat, M. Kanter, B. Litvak, A. Yahalom, B. Yu. Kapilevich
    CJS, Ariel
  • A. Gover
    University of Tel-Aviv, Faculty of Engineering, Tel-Aviv
  The existing through-wall imaging (TWI) systems operate in 1 – 10 GHz, basically, in order to reduce an attenuation caused by building material. However, the spatial resolution is drastically degraded when the operating frequency is relatively low. On the other hand, a majority of building materials demonstrate increased losses as the frequency increases. As a result, higher RF power from the source is required. The Israeli mm-wave FEL provides unique opportunity to solve the above TWI problem permitting to deliver output power 100-1000W at 85-105 GHz. Design of TWI system operating on mm-waves needs comprehensive study of constitutive parameters of different building materials. This paper describes systematic measurements of effective attenuation constant of typical building materials such as concrete bricks, wood, tiles, sand, gypsum, etc. on mm-waves using powerful FEL radiation. Since the Rayleigh criterion for surface roughness cannot be satisfied for some of measured materials, scattering and depolarization effects lead to increasing measured attenuation in comparison with bulky material. Additional experiments were performed to estimate a contribution of these effects into the measured attenuation.  
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THBAU05 The Scientific Programme of the UK Fourth Generation Light Source: 4GLS
  • P. Weightman
    STFC/DL, Daresbury, Warrington, Cheshire
  This talk will describe the proposed UK Fourth Generation Light Source (4GLS) and the prototype facility that is nearing completion at the Daresbury laboratory. The 4GLS design is based on a 600 MeV Energy Recovery Linear Accelerator (ERL) optimised to deliver high brightness radiation at energies below 100 eV. The ERL drives three free electron Lasers (FEL’s): an IR-FEL tunable over 2.5 to 200 mkm, a VUV-FEL tunable over 3 to 10 eV and a X ray FEL tunable over 10 to 100 eV. The source will also generate both high average power (2.6 kW) and high peak power (100 MW) sources of terahertz radiation. The emerging scientific programme for 4GLS will also be described with an emphasis on proposals to exploit its capabilities in the VUV, infrared and terahertz regions of the electromagnetic spectrum. There are particularly exciting prospects for research programmes that exploit various combinations of the 4GLS light sources in pump probe experiments  
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