Presentation on theme: "X Band Vacuum Devices Presented by: Tony Johns,"— Presentation transcript:
1 X Band Vacuum Devices Presented by: Tony Johns, CPI Europe, Surrey, EnglandTel: +44 (1932) Fax: +44 (1932)Mobile: +44 (7880)With material from: Adam Balkcum, Steve Lenci, Mike Cusick, Peter KoldaCPI, Palo Alto, California, USAIntroductionTony’s experience and history with companyAcknowledge contributors to presentation
2 Historical Timeline1990: Eimac awarded an Emmy for technological achievement Klystrode IOT1965: Eitel-McCullough merges with Varian Associates to form Eimac Division2001: Current management team takes leadership2007: CPI acquires Malibu Research Associates1935: Eimac Division founded as Eitel McCullough, Inc.1954: CMP Division is established in Canada193019401950196019701980199020012004200620071948: CPI is originated as founding technology group of Varian Associates1959: Varian Associates acquires Bomac Labs in Beverly, MA.1971: Varian integrates SFD Labs of Union, NJ with Beverly MA, division renamed BMD1995: Leonard Green & Partners, L.P. purchases entire Electron Devices Business from Varian and forms CPI2004: Cypress Group Acquires CPICPI Acquires Econco Broadcast Service2006: CPI stock publicly trades -NASDAQ: “CPII"MPP & Eimac divisions consolidateIt’s all on the slide
3 Communications & Power Industries Inc. Publicly heldNASDAQ: “CPII"Established in August 1995Worldwide Sales and Service Organization1,700 Employees WorldwideSix autonomous business units:BMD Beverly, MA, U.S.A.CMP Georgetown, ONT, CanadaEconco Woodland, CA, U.S.A.MPP Palo Alto, CA, U.S.ASatcom Georgetown, ONT, Canada (Manufacturing)Palo Alto, CA, U.S.A (R&D, Marketing, Service)Malibu Research Associates, Camarillo, CA, U.S.A.Again, all on the slide
4 Manufacturing/R&D Locations 2Manufacturing/R&D LocationsGeorgetown, Ontario, CanadaCommunications & Medical Products Division—Manufacturing OperationWoodland, CaliforniaQuick trip to US and CanadaPalo Alto, California—R&D, Marketing, ServiceBeverly, MA Beverly Microwave Products DivisionCamarillo, CAMalibu Research Associates
5 Broad Product Offering Consultative Engineering Services CPI SpecialitiesHigh PowerHigh EfficiencyBroad Product OfferingConsultative Engineering ServicesA little motherhood and apple pie as we Yanks say.
6 Inductive Output Tubes Magnetrons Cross-Field Amplifiers Products SuppliedKlystronsGyrotronsHelix TWTsCoupled Cavity TWTsRing Bar TWTsPower Grid TubesInductive Output TubesMagnetronsCross-Field AmplifiersX-Ray GeneratorsSatellite Communications amplifiersAntennasCPI provides a broad range of microwave power sources.The predominant products for accelerator application are klystrons, Inductive Output Tubes (IOT’s), and magnetronsIOTs are suited to low frequency (200 MHz – 1.5 GHz) and are important in the accelerator marketGyrotrons are high frequency devices (28 GHz to 140 GHz) and are primarily used in fusion energy experimentsCPI BMD operation has built a number of window-couplers for scientific use
7 VTX6389G5 Helix X Band Products Typical Operating Parameters Frequency GHzPower Output CW 2.5 kWEfficiency 59 %Beam Voltage 15 kVBeam Current 1 AThe VTX6389G5 X band TWT, shown in the upper left, is one of the products in a broad array of helix devices offered by CPI. The 6389G5 is a 2.5 kW CW device and it operates with a prime power of 7.4 kilowatts. It has small signal gain (before gain compression) of 62 dB. Key features of helix devices are their broad band frequency performance with extremely linear power over that band. The gain variation typical of this particular device is 1.2 dB. This device is important in communications systems where multiple signals are amplified simultaneously. This device is typical of the state of the art in helix traveling wave tube technology.
8 VKL-8301 Multiple Beam Klystron Typical Operating ParametersFrequency GHzPeak Power Output 10 MWAve. Power Output 150 kWPower Asymmetry 0.7 %Efficiency 59 %Beam Voltage 120 kVBeam Current 141 AMicroperveance 3.4RF Pulse Length 1.5 msSaturated Gain 49 dBCathode loading 2.2 A/cm2The prototype MBK is at DESY HamburgPresently building a 2nd generation MBK that is designed to operate horizontally. It was just loaded in the test stand and results are expected in JanuaryThe VKL-8301 is a recent high power klystron that was developed for the superconducting accelerator of the European X-ray Free Electron Laser. Although this particular klystron operates in L-band, it is an example of the new types of devices that CPI is currently investigating. This klystron is a higher-order mode multiple beam klystron. It has six cathodes set on a large bolt circle that drive TM02 (or higher-order mode) cavities. The advantage of multiple beams is that more of the beam power is carried in the beam current so that for a given rf output power, the operating voltage can be greatly lowered. Further, because the individual electron guns have a low microperveance, high efficiency can be maintained (as efficiency increases with lower microperveance): a distinct advantage for a large-scale accelerator. This klystron produced 10 MW peak, 150 kW average rf output power with an efficiency of 59% at a beam voltage of only 120 kV. By comparison, a standard single beam klystron with comparable efficiency would have operated at approximately 240 kV. Another advantage of this device is the use of large cavities which allows the cathodes to be placed on a large bolt circle. This allows the cathodes themselves to be large which lowers the cathode current density loading. As shown in the table, the loading is about 2 amps per square centimeter which equates to over 100,000 hours of expected cathode life. CPI is currently working on a new version of this klystron for the same application. It will be smaller in size for reduced cost but will still have low cathode current density loadings and a long life. The device is currently in test and the preliminary results are very encouraging.Used in European X-Ray FEL at DESY. Potential use in ILC. Horizontal version in progress with integrated X-ray shielding and cart currently in test.
9 Typical Operating Parameters VKL-9130 IOTTypical Operating ParametersFrequency GHzPeak Power 90 kWBeam Voltage 42 kVBeam Current 3.4 ABandwidth (-1 dB) 2 MHzGain 20 dBEfficiency 60 %IOT’s are “low” frequency devices (up to 1.5 GHz)One application of this integral cavity version is operated in pulsed mode up 90 kW peak with 1.5 msec pulse lengths at 10 Hz.The tube can also be operated at 30 kW CWCurrently developing a higher power version at 120 kW CWRecent testing successful at FZDCurrently developing 120 kW CW device
10 Typical Operating Parameters VKX-7864B Klystron250 kW CW in X-BandTypical Operating ParametersPower Output kWBeam Voltage 51 kVBeam Current ASupply Power kWEfficiency 44 %Frequency GHz1dB Bandwidth 60 MHzSaturated Gain 45 dBCavities 6Cooling Method liquidThe VKX-7864B is a high power CW X-band klystron. It is used by NASA’s Jet Propulsion Laboratory in their Deep Space Radar Transmitter. The klystron itself is mounted directly into the base of the antenna. The tube produces 250 kW CW at 8.56 GHz with 44% efficiency and 45 dB of gain to create a combined power of 500 kW CW. As can be seen, the collector accounts for most of the size and weight of the klystron. That is because it must be capable of dissipating the full beam power (more than 550 kW CW).
11 VTX-5681 Coupled Cavity TWT 100 kW Pulsed in X-bandTypical Operating ParametersFrequency GHzPeak Power Output 100 kWDuty 35 %Saturated Gain 49 dBBandwidth (-1 dB ) 1 GHzBeam Voltage 45 kVBeam Current 11 ALiquid cooledSolenoid focusedModulating anode controlled beam (50KV swing)Device used in high power radarUnits may be combined for added powerPhase matching possible over the desired bandwidthState of the art in high power coupled cavity traveling wave tube technology
12 VKX-7841 KlystronUsed in experimental accelerator research circa 1980, 5 were made. Very compact.Typical Operating ParametersFrequency GHzPeak Power Output kWAve. Power Output 0.2 kWSaturated Gain 71 dBBandwidth (-1 dB ) 45 MHzEfficiency 28 %Beam Voltage 8 kVBeam Current 30 AThe VKX-7841 was an experimental tube developed in the late ‘70s for a small experimental accelerator. It had a fairly high peak power of 600 kW at 9.5 GHz with a modest average power of only 200 W required for the application. It used periodic permanent magnet focusing and was cooled by a water cooled baseplate which made for a very compact device. The high voltage hook-up to the electron gun was also unusual and compact. It consisted of a plug into a ceramic socket directly on the gun which eliminated the need for any oil even though it was operating at 78 kV. Five of these devices were made.
13 Market drivers CPI Response Requirements for higher efficiency Recent AdvancementsMarket driversRequirements for higher efficiencyDesire for lower beam voltagesNeed for smaller sizeCPI ResponseSheet Beam KlystronPPM Focused Klystron
14 Typical Operating Parameters VKX-7993 Klystron2.7 MW PulsedTypical Operating ParametersFrequency GHzPeak Power 2.7 MWPeak Power (goal) 5.5 kWSaturated Gain 52 dBBandwidth (-1 dB ) 65 MHzEfficiency 43 %Beam Voltage 120 kVBeam Current 52 AThe VKX-7993 is a modern, high power and compact X-band amplifier. It nominally produces 2.7 MW peak and 5.5 kW of average power at 9.3 GHz but has been operated as high as 3.3 MW. The amplifier has a fairly high gain of 52 dB with a reasonably good efficiency of 43%. Periodic permanent magnetic focusing was used to reduce its size and weight. The complete klystron with integrated X-ray shielding weighs only 60 pounds and is 24 inches long.Compact device, recently in production
15 VKX-8293A Sheet Beam Klystron Sheet Beam TechnologyTypical Operating ParametersFrequency GHzPeak Power Output 2.7 MWAve. Power Output 0.3 kWSaturated Gain 42 dBEfficiency 25 %Beam Voltage 76 kVBeam Current 144 AFirst of a kind device!Goal is 5 MW peak and XX% efficiency.CPI and our customer were very pleased in achieving 2.7 MW on the prototype. Presently being rebuilt with minor corrections to the beam optics. Expect test results in January.Note the target operating voltage of 76 kV. Typical single beam klystron would require operation at 130 kV for 5 MW of output power.Device is PPM focused.
16 Sheet Beam Klystron The device advances the state of the art. Accelerating cavity fields are uniform across the web of the beam (X-dimension) by operating individual cavities at their cutoff frequency.SBKs cavities are overmoded transversely to the beam and usually require multiple gaps in the direction of the beam (Z-dimension) in order to improve their coupling to the beam. A “mode forest” results, but it always possible to move the various modes and avoid interference with the operating frequency.The SBK is a single-frequency amplifier, but, pound-for-pound the most powerful among linear beam tubes.
17 Sheet Beam Formation Drift Tunnel Cathode Focus Electrode Anode Beam DirectionElectron gun of a sheet beam device.NOTE – the light blue represents the region between the Cathode/Focus Electrode and the anode, as well as the beam tunnel
18 VKX-8293A Sheet Beam Klystron Beam transmission was 63% for above parameters.Best transmission was 94% at a much lower operating voltage.Cathode position will be adjusted to improve transmission.
19 X band frequency range fertile ConclusionsX band frequency range fertileEfficiency continues to improve, over 60%Size of products shrinkingModern design codes allow complex analysis of beam dynamicsNew RF structures possiblePower outputs from hundreds of watts to tens of megawattsAttracting new engineers into vacuum device field
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