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Vacuum Electronics Conference (IVEC), 2011 IEEE International

Date 21-24 Feb. 2011

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Displaying Results 1 - 25 of 262
  • [Front inside cover]

    Publication Year: 2011 , Page(s): c2
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    Freely Available from IEEE
  • [Front matter]

    Publication Year: 2011 , Page(s): i - xxviii
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    Freely Available from IEEE
  • Relativistic effects in microwave vacuum electronics

    Publication Year: 2011 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (253 KB) |  | HTML iconHTML  

    Being squeezed by competitors, the vacuum microwave electronics is made to enhance output powers, that should be provided with using sufficiently high beam voltages. The resulting increase of electron velocities is accompanied with a number of favorable relativistic effects. View full abstract»

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  • Microwaves and particle accelerators: A fundamental link

    Publication Year: 2011 , Page(s): 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (32 KB) |  | HTML iconHTML  

    Summary form only given. John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. The development of radar and high power vacuum electronics, especially microwave power tubes like the magnetrons and the klystrons in the pre-second world war era, was instrumental in the rapid development of circular and linear charged particle accelerators in the second half of the twentieth century. We had harnessed the powerful microwave radio-frequency sources from few tens of MHz to up to 90 GHz spanning L-band to W-band frequencies. Simultaneously in the second half of the twentieth century, lasers began to offer very first opportunities of controlling charged particles at smaller resolutions on the scale of wavelengths of visible light. We also witnessed in this period the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra small structures and ultra-fast processes continues. These developments depend crucially on yet further advancements in the production and control of high power and high frequency microwaves and light sources, often intricately coupled in their operation to the high energy beams themselves. We give a glimpse of the recent developments and innovations in the electromagnetic production and control of charged particle beams in the service of science and society. View full abstract»

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  • Vacuum electronics in India

    Publication Year: 2011 , Page(s): 7 - 10
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (79 KB) |  | HTML iconHTML  

    The vacuum electronic era started with the invention of vacuum diode by JA Fleming in 1904. However, the foundation of microwaves was laid in India much earlier by one of the fathers of radio science Acharya Jagdish Chandra Bose in 1890's in Calcutta. He used waveguides, horn antenna, dielectric lenses, polarizer's and even semiconductor detector, while working at the 2.5 cm to 5 mm wavelength. Today, the vacuum electronic devices (VEDs) are an essential component of many defense, space, and high energy research and civilian systems employing rf, microwaves, or x-rays or simply high speed switching. Defense systems like Radar, electronic warfare, communication and missile systems; high energy particle accelerators, TeV colliders, fusion reactors, industrial and domestic-ovens, medical imaging, hyperthermia, high power electric transmission etc. all require VEDs. Presently, India is one among just a dozen countries in the world having the ecosystem of academia, research laboratories production enterprises and a significant domestic market in defense, space, civilian, high energy research and ISM sectors to nurture innovation in these devices. View full abstract»

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  • Vacuum electronic sources for high power terahertz-regime radiation

    Publication Year: 2011 , Page(s): 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (32 KB) |  | HTML iconHTML  

    Summary form only given. A recent resurgence of interest in new, more powerful, coherent sources of terahertz (THz) radiation (0.3-3.0 × 1012 Hz) has been driven by advances in fabrication and device physics modeling, emergence of new security threats, and application potential in high data rate communications, concealed weapon or threat detection, remote high resolution imaging, chemical spectroscopy, materials research, deep space research and communications, basic biological spectroscopy and biomedical diagnostics. This talk reviews recent advances and achievements in THz-regime vacuum electronic devices (VEDs). VEDs are intrinsically superior to solid state devices at handling high power or high power density. Development of VED sources of THz radiation has therefore primarily focused on applications calling for either high average power or high average power density, i.e., relatively high power in a compact package, and usually with the highest achievable device efficiencies. The VED source and critical enabling technology advances reviewed in this talk include EIKs, BWOs, TWTs, gyrotrons, FELs, beamline sources, microfabrication and cathodes. View full abstract»

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  • Design and development of 2 to 3 octave band helix mini-TWTs

    Publication Year: 2011 , Page(s): 15 - 16
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (168 KB) |  | HTML iconHTML  

    A number of helix mini traveling wave tubes (TWTs) operating over a multi-octave frequency band have been designed and developed during last ten years. In this paper, the critical areas of design and development of these devices are elaborated and supported by experimental results. Details about an ongoing development of 2 to 7 GHz, 100 W helix TWT are also presented. View full abstract»

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  • Development of Ka-band 500 W CW Helix TWT

    Publication Year: 2011 , Page(s): 17 - 18
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (78 KB) |  | HTML iconHTML  

    This paper describes the performance of a new Ka-band 500W power Helix TWT (LD7338) which is a currently under development for the Broadband Digital Satellite Communication. The first engineering model is now under evaluation and has achieved the output power of more than 500W CW at saturation. View full abstract»

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  • RF output multipaction margin of travelling wave tubes

    Publication Year: 2011 , Page(s): 19 - 20
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (135 KB) |  | HTML iconHTML  

    The paper show the multipaction capability of Thales RF output solutions for today high power L- and S-Band TWTs. Thales accepts that a real prediction of the multipaction onset level of complex coaxial structures like in example a TNC connector, with dielectrics, air gaps and complex electric fields inside, is not possible with today knowledge. Therefore Thales prefers to qualify their RF output interfaces with different multipaction tests, which were assisted by ESA and their multipaction experience. We could demonstrate that our designs have a 6 dB multipaction margin by test and a new multipaction test for L-Band will show if our standard TNC connector will have the same margin or if for high power L-Band applications a SC connector has to be the preferred solution. For very high power S-Band applications we see definitely a WR340 ¼ height waveguide output as the best solution which is already today a standard interface at satellite level. In summary Thales has solved a very critical area for high power tubes in L- and S- band and is able to fulfill today multipaction requirements. View full abstract»

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  • Performance enhancement of W-band CW TWT

    Publication Year: 2011 , Page(s): 21 - 22
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (68 KB) |  | HTML iconHTML  

    Backward wave oscillation (BWO) and other parasitic oscillation are encountered in the process of manufacturing W-band TWT. In order to eliminate the oscillation, a kind of attenuation material is coated to the folded waveguide wall. This method presents a good performance to enable stable working of the TWT and increase the output power to 15W at the same drive level. View full abstract»

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  • Design of a K-Ka band helix TWT

    Publication Year: 2011 , Page(s): 23 - 24
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (142 KB) |  | HTML iconHTML  

    This paper briefly presents the details of the design of a K-Ka band, 40 W CW, millimeter-wave helix TWT. Sub-system level design and TWT development issues are also presented. View full abstract»

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  • Design and development of a 6 MW peak, 24 kW average power S-band Klystron

    Publication Year: 2011 , Page(s): 25 - 26
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (118 KB) |  | HTML iconHTML  

    A 6 MW peak, 24 kW average power S-band Klystron is under development at CEERI, Pilani under an MoU between BARC and CEERI. The design of the klystron has been completed. The electron gun has been designed using TRAK and MAGIC codes. RF cavities have been designed using HFSS and CST Microwave Studio while the complete beam wave interaction simulation has been done using MAGIC code. The thermal design of collector and RF window has been done using ANSYS code. A Gun Collector Test Module (GCTM) was developed before making actual klystron to validate gun perveance and thermal design of collector. A high voltage solid state pulsed modulator has been installed for performance evaluation of the tube. The paper will cover the design aspects of the tube and experimental test results of GCTM and klystron. View full abstract»

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  • Development of high power CW 3.7 GHz klystrons for fusion experiments on Tore Supra

    Publication Year: 2011 , Page(s): 27 - 28
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (133 KB) |  | HTML iconHTML  

    The paper will present in detail the process and results of test of the klystrons for the factory acceptance tests and for the validation tests at Tore Supra, along with the dispersion observed on their characteristics. View full abstract»

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  • The wideband inductive output tube

    Publication Year: 2011 , Page(s): 29 - 30
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (131 KB) |  | HTML iconHTML  

    L-3 Communications, Electron Devices Division (EDD) has developed an inductive output tube (IOT) with large instantaneous bandwidth for radar and communications applications. As in conventional IOTs, this wideband IOT (WBIOT) provides high efficiency, good linearity, and compact size through emission-gated modulation of the electron beam at the cathode surface. Increases in gain, bandwidth, and duty factor will be discussed through test results and simulation. View full abstract»

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  • Simulation and characterization of Cylindrical RF cavity with output section coupling for 250 kW CW C-band klystron

    Publication Year: 2011 , Page(s): 31 - 32
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (83 KB) |  | HTML iconHTML  

    The klystron is a microwave tube capable to produce very high power that find wide use in communication, radar, material processing, particle accelerators and thermonuclear fusion reactors. The RF section has an important role in deciding the RF performance of the tube, such as its gain, band width, efficiency etc. The RF section is a integration of 6 numbers RF resonant cavities. The fabrication of cavities was carried out through machining of piece parts, brazing, and characterized through cold testing. Output section of klystron consist of reduce wave guide, step transformer and RF window assembly coupled with RF cavity. The coupling parameters loaded Q and VSWR are analytical calculated to match the cavity with output section. The simulation of output coupling carried out using CST microwave studio code. The analytical results are well matched with simulated results. An experimental assembly of RF cavity with output section fabricated. The paper presents the design and Characterization of Cylindrical RF cavity with Output section coupling for a 250 kW CW C-band klystron being developed at CEERI Pilani. View full abstract»

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  • Development of the S-band high power klystron with bandwidth of 12%

    Publication Year: 2011 , Page(s): 33 - 34
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (109 KB) |  | HTML iconHTML  

    The development of broadband high power klystron has being done in the Institute of Electronics, Chinese Academy of Sciences (IECAS), and the breakthrough of the bandwidth of klystron has been obtained continuously. In S-band, after the achievement of 10% and 11% bandwidth, the relative instantaneous bandwidth of 12% has been brought to success in 2009. The paper introduces the design, simulation and test results of this klystron in detail. View full abstract»

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  • High current density reservoir cathode development

    Publication Year: 2011 , Page(s): 35 - 36
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (190 KB) |  | HTML iconHTML  

    Research is continuing in development of high current density, reservoir cathodes. The research is focused on investigating different reservoir materials and applications. An additional goal is to increase the current density capability and further extend the lifetime. View full abstract»

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  • Fabrication and testing of sintered wires reservoir cathodes at Semicon Associates

    Publication Year: 2011 , Page(s): 37 - 38
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (91 KB) |  | HTML iconHTML  

    Recent years brought a new challenge to the microwave industry for which traditional dispenser cathodes could not provide an answer. Extremely small dimensions and tight tolerances along with high power and frequency requirements prompted scientists and engineers to search for a new approach in cathode technology. In their work [1]-[2], Ives at al. introduced a novel technology that immediately drew attention of the industry. Controlled porosity reservoir cathodes from sintered tungsten wires offered a solution to many unsolved issues in cathode technology which initial testing performed at Calabazas Creek Research confirmed. After obtaining the legal rights to this technology, Semicon Associates manufactured and tested several different cathode assemblies in order to validate design and manufacturing processes. Results will be presented. View full abstract»

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  • Tungsten-rhenium mixed metal matrix cathodes

    Publication Year: 2011 , Page(s): 39 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (89 KB) |  | HTML iconHTML  

    In this paper, studies are carried out on W-Re mixed matrix cathodes developed in house, will be discussed. It has been observed that a proper choice of rhenium particle size is essential for obtaining good emission density. The cathodes have been prepared by impregnating W-Re (50%-50% by weight) mixed metal matrices with 5:3:2 barium calcium aluminates. A current density of 20 A/cm2 has been achieved at 1360K. Life testing of these cathodes has been carried out in closely spaced diode configuration. Variation of work function and emission current density after 35000 Hrs of life will be presented. View full abstract»

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  • Scandate dispenser cathode for 220 GHz 50 W sheet beam travelling wave tube amplifier

    Publication Year: 2011 , Page(s): 41 - 42
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (238 KB) |  | HTML iconHTML  

    Sc2O3-doped W powder for use in high current density thermionic cathodes has been made by the sol-gel method with different particle sizes. Sc2O3-W matrix cathodes have been prepared from these powders, and have shown excellent emission properties. A space charge limited current density of 40 A/cm2 at 850°C, and 170 A/cm2 at 1050°C have been obtained by using 300-500 nm Sc2O3-doped (5.0 wt.%) W powders. Life testing is ongoing with a continuously pulsed loading of 50 A/cm2 at 1050°C after >; 104 hours. The machined cathode made from 1-2 micron size Sc2O3-doped W powder can reach 160 A/cm2 at 1050°C during pulsed operation. The CW cathode testing is being developed for practical application. View full abstract»

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  • High current density ternary-alloy-film dispenser cathode for terahertz vacuum devices

    Publication Year: 2011 , Page(s): 43 - 44
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (106 KB) |  | HTML iconHTML  

    Dispenser cathode is used in microwave tubes as source of electrons. We investigate high current density emission capabilities of alloy-coated cathodes used for terahertz vacuum devices. In this paper the developmental work carried out on ternary-alloy-film cathode (2Os:2Re:1W) and the results are presented. The cathodes were tested inside a closed spaced diode and also analytical chamber containing Auger Electron Spectroscopy (AES), Thermionic Emission Microscope (THEM) facility. Emission current densities measured in the diode structure at 1300° K temperature were above 60 A/cm2. The work function was found 1.72 eV using 73% slope method. To ensure the life of the cathode accelerated life test has been carried out in closed spaced diode at 1300° K temperature. View full abstract»

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  • Energy calculation for magnetically insulated line oscillator

    Publication Year: 2011 , Page(s): 45 - 46
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (83 KB) |  | HTML iconHTML  

    MILO has been analyzed for its beam wave interaction and the RF released energy has been calculated. The analytical results are obtained, typically, for a S-band MILO, and released RF energy is found as 2.5 Joule at 300 kV applied voltage. The analytical results has also been validated through PIC simulation code MAGIC and found to be in close agreement. View full abstract»

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  • High power microwave generation from a reflex triode virtual cathode oscillator

    Publication Year: 2011 , Page(s): 47 - 48
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (139 KB) |  | HTML iconHTML  

    Experiments were carried out to generate intense relativistic electron beams and High Power Microwaves (HPM) with reflex triode geometry from 1 kJ pulse power system. The typical electron beam parameters were 300 kV, 12 kA, and 300 ns, with a current density of a few hundreds of amperes per square centimeter. We present a power optimization study of the HPM generated from the reflex-triode vircator for various anode-cathode (AK) gaps. A horn antenna setup with diode detector and attenuators was used to measure the microwave power. The HPM frequency was measured with a D-dot probe along with a high band width oscilloscope. It was found that the microwave power and E-field peaks at 15 mm AK Gap and the frequency at this gap is 2.2 GHz. The highest microwave power is emitted when all the power is delivered into a single frequency with minimal mode hopping. View full abstract»

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  • Smaller spot size Flash X-ray generation from KALI 5000 system

    Publication Year: 2011 , Page(s): 49 - 50
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (122 KB) |  | HTML iconHTML  

    A Flash X-ray diode has been designed and developed for generation of single shot, nanosecond duration x-rays from KALI-5000 Pulse Power System (0.8-1 MV, 40 kA, 100 ns). The typical electron beam parameter was 500 kV, 8 kA, 100 ns, with a few hundreds of A/cm current density. The spot size for different diode configurations varied from 4 mm to 2 mm. X-ray radiograph of various metal objects were taken on X-ray films. The diode voltage and current waveforms were analyzed with the space-charge limited flow model. The anode and cathode plasma expansion velocities were calculated using the perveance data and varies from 2.5-3.3 cm/μs. Time integrated x-ray dose was measured using pen dosemeter and the on-axis dose was 10 mR at 1m distance from the window. The radiograph of stainless steel objects shows good resolution. View full abstract»

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  • Development of high voltage pulser for High Power Electromagnetic (HPEM) simulation

    Publication Year: 2011 , Page(s): 51 - 52
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (103 KB) |  | HTML iconHTML  

    In the present scenario, the pulse power technology plays a vital role in variety of applications ranging from industrial & medical fields to scientific & defence applications. One of the defensive applications is in the hardness assurance testing of the hardened mission critical defence electronics. Sophisticated mission critical defence electronics is highly susceptible to the transient Electromagnetic Environment (EME) of high intensity. Hence sufficient protection needs to be given to such critical defence electronics to withstand against the damaging & upsetting effects of High Power Electro Magnetics (HPEM). In order to validate the degree of protection provided, the hardened system(s) needs to be exposed to the simulated transient environment. This requires the development of a high voltage pulser with a very peculiar wave shape of the output impulse voltage. The challenges faced in realization & development of a typical 640 kV High Voltage pulser for one of the HPEM environment simulators are discussed in this paper. View full abstract»

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