IC-IIFC meeting V.K.Handu and Manjiri Pande Technical Physics Division, Bhabha Atomic Research Center, Mumbai, India

Outline of the presentation 1. Technical capabilities of the Technical Physics Division 2. High power Radio Frequency source development for Accelerator applications 3. Solid state RF amplifier development

Materials for Device Applications Thermoelectric Devices: Converts Heat into Electricity 1. Device consists of: n- PbTe and p-TAGS-85 pellets 2. Operating temperature: 500  C 3. Efficiency: 6% Gas Sensors: Detects toxic H 2 S gases 1. Sensor based on CuO:SnO 2 films 2. Operating temperature: 180  C 3. Minimum detection limit: 1 ppm Single Crystals: Dosimeter & radiation detection NaBi(WO 4 ) 2 LiF Crystal Glass and Ceramics: Glass-to-metal seals and biocompatible ceramics glass-to-metal seal Specialized glass components Ion Implanted Si: Radiation Detectors 1. Active area of mm 2 2. Energy resolution: keV Molecular Electronics: Electronics using molecules Molecular diode using Porphyrin/ C60 bilayer Si

TOF - MASS SPECTROMETERS for CLUSTER STUDIES & SURFACE ANALYSIS A Magnetron B Cluster source C Ion optics D Reflectron E ESI-TOF setup HIGH RESOLUTION DUAL TIME OF FLIGHT (TOF) CLUSTER BEAM SETUP Comprises of two TOF-MS at mutually perpendicular directions and is coupled to a molecular/ion beam source with : 1)Time scale of measurement: microseconds 2)Resolution :1.7 nanoseconds, 3)Dynamic range: 2000, 4)Sensitivity: picomole F ESI source G Mass gate H CHP detector M Mass flow controllers ION-TRAP, TIME-OF-FLIGHT SECONDARY ION MASS SPECTROMETER TOF - SIMS provides ultimate sensitivity (sub ppb level) for studying impurities and trace elements on sample surfaces. A high energy, very fine focus, 25 keV Gallium Ion Source provides HIGH SPATIAL RESOLUTION ( ~ 250 NM), and a two- stage Reflectron with time focusing for very HIGH MASS RESOLUTION ( M/ΔM > 10,000) to distinguish atomic and molecular species. SAMPLES IN ANY FORM CAN BE ANALYZED. Surfaces can be raster scanned and reconstructed element by element to form a complete 3-D elemental Image of the sample (CHEMICAL IMAGING).

MASS SPECTROMETRS for TRACE ANALYSIS and RATIO MEASUREMENTS INDUCTIVELY COUPLED PLASMA MASS SPECTROMETER (ICPMS) THERMAL IONISATION MASS SPECTROMETE FOR Sr, Sm, Nd, U & Pu THERMAL IONISATION MASS SPECTROMETE FOR Sr, Sm, Nd, U & Pu ION SOURCE: Triple filament Thermal Ionisation (TI) with 12 stage turret and High Transmission ion optics ANALYSER: 30 cm radius, 90 0 deflection Stigmatic Focusing COLLECTORS : Five Collectors for Sr,U,Pu; Seven Collectors for Nd, Sm BEAM ENERGY: Upto 10 kV RESOLUTION: 450 (10%) SENSITIVITY : 1 ion per 600 atoms for U MASS RANGE: amu PRECISION : 0.06% (Ext.) for U 20 ppm (Ext.) – Nd, Sr ABUNDANCE SENSITIVITY: 25 ppm w/o RPL, <5 ppm with RPL ION SOURCE: ICP - Three tube fassel type torch RF GENERATOR : MHz, 2 kW with Automatic Impedance matching INTERFACE : Two water cooled Nickel cones SAMPLER CONE - 1 mm dia.; Skimmer cone mm dia. MASS RANGE : amu RESOLUTION : 1 amu typical COLLECTOR : Dual mode CEM (analog/pulse modes) SENSITIVITY : 5 Mcps per ppm of In ION OPTICS : Double deflecting type with einzel lens DET. LIMIT : Sub ppb to ppb ANALYSER : Quadrupole – 16mm rod dia., 200 mm long with Pre filters (1.2 MHz)

X-RAY PHOTO-ELECTRON SPECTROSCOPY (PES) Beamline (BL-14) on INDUS-2 Energy range : 0.8 – 15 keV Source : bending magnet Divergence : 3 mrad Resolution :  Photon flux : – mm -2 s -1 Layout of PES beamline Photograph of PES beamline without hutch Photograph of PES beamline with hutch Double Crystal Monochromator (DCM) built inhouse 1. Energy scan range: 0.85 keV to 15keV. 1. Energy scan range: 0.85 keV to 15keV. 2. Resolution: ~ Resolution: ~ Overall Pressure: < 5x mbar, 3. Overall Pressure: < 5x mbar, 4. Crystals: Si (111) 2d = A°, 4. Crystals: Si (111) 2d = A°, 5. First crystal (size: 10cm x 10cm, 8mm thick) 5. First crystal (size: 10cm x 10cm, 8mm thick) 6. Beam width adjustable by input and output slits. 6. Beam width adjustable by input and output slits. 7. Second crystal is slotted, tapered and bent for horizontal focusing. 7. Second crystal is slotted, tapered and bent for horizontal focusing. 8. Movements of the crystals are controlled by PC and stepper motors. 8. Movements of the crystals are controlled by PC and stepper motors. Experimental station Hemispherical analyser SRS Beam observed through Be window Photograph of PES beamline experimental station Specifications of DCM Specifications of beamline: Applications of beamline:

Design details of ARPES / PEEM beamline (BL-6) on Indus-2  Beam spot at the sample :H= cm,V = cm  Photon flux at the sample : ~ ph/sec  Energy resolution : (ΔE/E) ~  Energy range : (10 – 8000eV) Main component of the beamline: 1.Slits, 2. Collimating mirror, 3. Plane grating monochromator, 4. DCM,5. Focusing mirror, 6. Pair of KB mirror for micro-spot at the sample, 7. Toroidal shape analyzer, 8. Detector, 9. Cryo cooled sample manipulator. This beamline will have two branches, one devoted to high resolution angle resolved photo-emission spectroscopy and other for photo- emission electron microscopy. Design details of Toriodal analyser Design details of PEEM analyzer ARPES is used to study Fermi surface mapping of crystalline material. Detail of PEEM: Photo-Emission Electron Microscopy (PEEM) is an imaging technique that involves shining linearly or circularly polarised X-rays onto the surface of a sample to provide spectroscopic information on nm scale. Layout of ARPES/PEEM beamline ARPES station with Toriodal analyser PEEM station with PEEM analyser Specifications of beamline: ANGLE RESOLVED PHOTO EMISSION SPECTROSCOPY (ARPES) / PHOTO EMISSION ELECTRON MICROSCOPY (PEEM) Beamline (BL-14) on INDUS-2

Possible scientific experiments Beamline design guided by following three types of macromolecular experiments; a) use of very small crystals b) variable wavelength optimized anomalous scattering experiments c) Laue experiments for time resolved studies. Diffraction studies of very small crystals Multi or single wavelength anomalous dispersion experiments Time resolved studies RadiationMonochromatic, TunableMonochromatic, Tunable White beam Wavelength range (Å)0.5 – – 2.0  / – m 17m17m 24m24m CMDCM TMTM 36m36m Source Sample Optical design and experimental station A schematic layout of the beamline (Side view) depicting various optical elements used; CM-Cylindrical Mirror, DCM-Double crystal monochromator, TM-Toroidal mirror Beam size: 0.33 * 0.40 mm 2 Double crystal monocromator Energy range : keV Energy resolution (ΔE/E) : 2.5×10 -4 Experimental Station Detail Monochromatic x-ray beam XRD Protein structure (In collaboration with HP&SRPD,SSPD) Typical beam parameters required for these experiments are listed bellow. PROTEIN CRYSTALLOGRAPHY Beamline (BL-14) on INDUS-2

Turrett & Collector Cups Control UnitSputter Ion Pump Power supplies for (70 l/sec Pump) Quadrupole DC, EI Source & Ion optics suppliesSolenoid Power supplies for Klystron Wall Current Monitor placed in the test jig for characterization DCCT measurement setup SMPS Based Other developments within the division

Development of high power RF sources RF power development activity at TPD, BARC: For accelerator application: MHz, 200 Watt RF source for 14 MeV Neutron Generator MHz, 60 kW RF system for deuterium 400 KeV RFQ accelerator MHz, 2.5 kW (CW and pulse mode) driver for 60 kW RF system MHz Klystron based RF system for LEHIPA MHz, 1 kW RF system for Heavy ion RFQ MHz solid state RF power amplifier development For Mass Spectrometer: MHz, 1.5 kW RF Generator for ICP-MS MHz, 4 kVpp RF source for Quadrupole Mass Spectrometer (QMS)

Extraction Voltage 0-7 KV Solenoid Coil 13 V / 1 A Lens (Focus) 0 – (-17KV)/1mA RF Power System 100 MHz / 250 Watts HV Column 50 KV RF Ion Source PURNIMA Sub Critical Core Assembly RFQ BASED 14 MeV NEUTRON GENERATOR LEBT (400 KeV) RFQ RF Power Supply 70 KW/ 350 MHz D + RF ion source DC HV column 400 KV DCPulse / DC power supply D + ion current Deuterium plasma

100 MHz RF source for (D+) ion source of 14 MeV NEUTRON GENERATOR (DC ACCELERATOR based) 1) Tetrode based RF supply 1. Frequency: 100 MHz 4. Power Gain: 30 dB 2. Power : 200 W 5. Device: BEL 250 CX 3. Class C, grounded grid 6. Efficiency: 60 % 2) Solid State R.F. Amplifier  Test results 1. Frequency: 100 MHz 2. Power: 256 W 3. Efficiency: 63.5% 4. Power Gain: 13.7 dB 5. Device: MOSFET MRF 141G 6. Class ‘C’  Status of Solid State R.F. Amplifier Solid state version for the same has been developed, tested and integrated with RF ion source. D + current obtained after DC acceleration is 170 microampere.

350 MHz, 60 kW RF system for deuterium 400 KeV RFQ For 400 KeV (D + ) radio frequency quadrupole (RFQ) accelerator based Neutron Generator (pilot ADS project), the RF system has been tested up to 14 kW and efforts are in progress for 60 kW testing. RF system set up ( MHz) RF Power waveform on spectrum Analyzer

RF Driver: 350 MHz, 2.5 kW (CW and pulse mode) for 60 kW RF system CW mode results: Frequency: 350 MHz Power: Watt (CW) Gain: 15 dB Efficiency: 56% Class A Device: TH 393 The amplifier has been tested in pulse mode also. Pulsed Mode Results: 1.Center frequency: 350 MHz 2.Pulse width:1 mS 3.Pulse repetition rate: 100 Hz 4.Pulse power (pk):4 kW Tetrode and its cavity DC Bias supplies and input RF driver A new RF driver for 60 kW RF system has been developed based on tetrode TH 393. Single pulse detailsSeries of pulses / pulse train

Klystron Driver 100 Watt Master Oscillator / Frequency Synthesizer RF Control Klystron Amplifier Modulating Anode Power Supply, - 65 kV kV/ 25 A Cathode Power Supply Y- Junction Circulator 1. 0 MW Directional Coupler 1 MW Focus Coil P/S Heater P/S Vacuum ion P/S High Power RF load Water Cooling Arrangement for 1. Klystron 2. Circulator, 3. RF Load Overall Control Electronics (Interlock & Protection) MHz KLYSTRON BASED RF POWER SOURCE & DISTRIBUTION SYSTEM for LEHIPA MHz KLYSTRON BASED RF POWER SOURCE & DISTRIBUTION SYSTEM for LEHIPA Wave guide Distribution System Accelerating Cavity Harmonic Filter RF Coupler 100 Watt solid state Driver

75 MHz, 1 kW RF system RF System: MHz RF power waveform at 75 and 150 MHz RF output waveform shape A heavy ion RFQ accelerator is being developed in BARC. To test the prototype version of it, a one kilowatt RF system has been developed. Its solid state version is being designed.

Solid state RF amplifier development 1.Experience on Solid-state driver for Klystron 2. Indigenous development of solid-state power amplifier at 350 MHz a. Amplifier modules b. Power combiners design & analysis c. 700 W Amplifier development 3. Proposal of 5 kW, 325 MHz Amplifier development a. Options b. Schedules

1. Solid-State Amplifiers Development 1st step: 100 W, MHz driver developed for Klystron Main Features of the this Driver Amplifier  Total Power Gain : 50 dB  No of cascaded stages : 3  Air cooled Heat sink  Protection by intermediate circulators  Efficiency : >60 %  Operation : Class AB & Class C

Details of Driver Amplifier BG Y 888 MRF 166 C MRF 275 G Dummy Load 100 W Amplifier RF in RF out

2. SSPA Program in 11 th plan( ) Development of a Solid-State high Power Amplifier 350 MHz Under this the following technologies are planned to develop 1.High efficiency rugged power modules at 300 W and 1 kW 2.Arbitrary power combiners and splitters using micro strip and coaxial technology at different power levels and different number of ports 3.Development of protection and control systems for high reliable operation 4. Feedback control for stability of power output

2.a. High Power Solid-State Modules Power output of Modules : 150 W (1 no)– Driver module for 700 W 250 W (4 no's) - Modules for Combining Device Technology used: VDMOS and LDMOS Input and Output impedances of device matched to 50 Ω by using two L- section matching networks and baluns. Design on FR-4 substrate Drop in circulator along with surface mount termination for amplifier protection against load variation Copper heat spreader along with water cooled channels for heat dissipation

Test Set-up for prototype RF power module VNA Spectrum Analyzer DC 28V, 40A Water Inter Lock Circuit Power Meter Driver Amplifier Power Meter Dir. Coupl. Dir. Power sensor Sig. Generator 1 kW Load Dir. Power sensor DUT NRT NRT-Z44 ZVR ACM-500 FSP 100 W SSPA

Tested Specifications of 250 W Modules Center Frequency : 350 MHz Bandwidth (3 dB) : 10 MHz Power output (sat.) : 250 W Power Gain : 8.5 dB Efficiency : 60% Protection : Circulator Operation : Class C Stability : Unconditionally stable Cooling Method : Water cooled Circulator Device O/p Balun Load I/p Balun O/P I/P

Measured Performance 1 dB Gain, 9.2 dB 1 dB P out 200 W P out Vs P in Gain Vs P in Max Gain Deviation, 1.8 dB Individual Module Gain & Phase deviation among modules

2.b. Design of Combiners/splitters To achieve high power using solid state amplifier modules, combiners and splitters are needed. Combiners/Splitters can be designed using different transmission line technologies i.e. micro-strip, coaxial line etc. It has been decided to design splitters (which are at low power) using micro-strip based technology and combiners which are at high power using coaxial lines. Among different Design technique for these combiners/splitters, Wilkinson technique has been used for this purpose.

2.b. Design specifications for combiners/Splitters Combiners have been designed using coaxial transmission line technology with air as dielectric. 1 to 4 way, 1 to 8 way combiners at different power levels. Return loss of >20dB at input ports (without internal resistors) with balanced input power. Return loss of better than 25dB at output port. Isolation among input ports better than 25dB. Transmission loss < 0.15dB

2.c. 700 W, 350 MHz Amplifier Sig. Generator 1 kW Load Power Meter Power Meter Power Meter DC 28V,100A Water 4:1 Combiner 1:4 Divider 200 W 140 W NAP-Z6 NRT-Z44 NRT NRT-Z W SSPA

2.c. Performance of 700 W SSPA Total no of modules: 4 +1 drive module Power Gain (1 dB) :19 dB Power Output :700 W Combining Losses :10% Input & Output VSWR : 1:1.2 Efficiency (Total) :40% Stability : Unconditionally stable Band width (3 dB) : 7 MHz

2.c. Measured Performance 19 dB 1 dB point 1 dB Output 700 W

Current status of 350 MHz SSPA Art work modified to improve the performance of modules for >300 W operation 1 kW PCBs designed and Boards under construction Water cooled assembly for 2 kW, ready Interlock circuit integrated Power supplies installed 2 kW Amplifier Assembly

3. Proposed Specification of 5 kW SSPA Center frequency : 325 MHz Bandwidth (3 dB) : 10 MHz Power output (1 dB), CW : 5 kW Gain (1 dB), minimum : 50 dB Gain Stability : +/-0.5 dB Stability : Un conditionally Stable Cooling : Water Cooled Input & Output VSWR : 1: 1.2 Harmonics & Spurious : <30 dBc Efficiency (Total) : > 40%

3. Block Diagram of 5 kW SSPA Direc 5 KW AMP Protection using analog and TTL i/p and o/p Feed Back DC Power supplies RF OUTPUT RF Input Water Dir. Coupler VCA

5 kW Amplifier Line-UP, option-1 BG Y 888 MRF 6V W, 30 dB100 W, 20 dB 8 × 800 W 19 dB 1:8 Divider Micro strip 8:1 Combiner Coaxial RF input 0 dBm >5 350 MHz

Simulation results: 1KW Module Simulation Results of 1KW, 325MHz RF power module Frequency sweep results Input power sweep Designed PCB on FR4

Option-2 BGY 888 MRF6 V W, 30 dB100 W, 20 dB 2 × 10 × 300 W 20 dB 1:10 Dividers Micro strip 10:1 Combiner Coaxial RF input 0 dBm >5 350 MHz Based on 300 W Solid state modules 1:2 Micro strip Divider 2:1 Coaxial Combiner

Simulation results: 350W Module Circuit Diagram Input Power Sweep results Frequency sweep Simulation Results for 350W at 350MHz RF power amplifier Input Power Sweep Plots

Simulation results: 350W Module Simulation results for 350W at 325MHz power module Input Power sweep Plots Frequency Sweep PCB Board

Protection Modules & total Amplifier is protected against the any of the combination fault conditions  Under voltage & Over voltage  Excessive reflected Power  Excess output power  Over current  Over input drive  Temp rise of heat sink  Low water flow rate

Feed Back and Control Gain Stabilization with in +/- 0.5 dB Ref. Gain set by ext./int., 0-10 V Reflection level set ext./int V Analog signals  Flow rate,  Temperature,  Forward power  Reflected power  Gain  Supply Current & Voltage

Proposed Schedule High Power solid-state amplifier of 1000 W at 350 MHz will be ready by 2011 High Power solid-state amplifier of 2.5 kW at 350 MHz will be ready by December 2011 Based on earlier 350 MHz: 1 kW, 325 MHz - two such modules ready by kW SSPA - one module ready by 2013

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