Kimball Physics FC-86 Water-Cooled Faraday Cup Assembly

Overview

The Kimball Physics FC-86 is a high-power, water-cooled Faraday cup assembly engineered for precise, stable measurement of electron or ion beam current in demanding vacuum environments. Based on the fundamental principle of charge collection within an electrically isolated, grounded conductive enclosure—shielded to minimize secondary electron emission and electromagnetic interference—the FC-86 delivers high-fidelity current quantification across beam energies typical of electron guns, ion implanters, focused ion beam (FIB) systems, and accelerator-based instrumentation. Its robust stainless-steel construction, integrated RF shielding, and optimized cup geometry ensure minimal signal distortion and excellent linearity from nanoampere to milliampere ranges. Designed explicitly for continuous-duty operation under high thermal load, the FC-86 supports beam power dissipation up to 1250 W without performance degradation—making it suitable for industrial processing, materials science irradiation studies, and high-brightness source characterization.

Key Features

• Water-cooled copper cup assembly with integrated cooling channels and standardized 1/4″ NPT inlet/outlet ports for compatibility with standard laboratory chillers or recirculating cooling systems.
• Electrostatically shielded housing fabricated from non-magnetic, ultra-high-vacuum (UHV)-compatible 304 stainless steel, featuring ConFlat® (CF) flange mounting options (typically 2.75″ or 4.5″ CF).
• Removable, phosphor-coated fluorescent screen mounted coaxially upstream of the cup aperture, enabling real-time visual alignment and qualitative beam profile assessment without breaking vacuum.
• Low-noise, guarded output connector (SHV or BNC, configurable) with integral bias compensation circuitry to suppress leakage current and improve signal-to-noise ratio at low-current levels.
• Optimized cup depth-to-diameter ratio and internal surface passivation to suppress secondary electron escape, ensuring measurement accuracy traceable to NIST-traceable current standards.
• Modular design permits integration with beamline diagnostics, raster scanners, and automated positioning stages via standard kinematic mounts.

Sample Compatibility & Compliance

The FC-86 operates in vacuum environments ranging from 1×10⁻⁹ Torr to atmospheric pressure (when used with differential pumping or windowed configurations). It accommodates electron beams (100 eV–100 keV) and singly/multiply charged ion beams (e.g., Ar⁺, Ga⁺, O₂⁺) with kinetic energies up to 200 keV. The unit complies with IEEE Std 100-2000 definitions for electrical measurement instruments and meets mechanical interface requirements per ISO 3567 (vacuum flange dimensions) and ASTM E1789-01 (standard guide for electron beam characterization). All wetted materials conform to outgassing specifications outlined in NASA SP-R-0022A for space-qualified hardware. No internal electronics require calibration certification; however, system-level current measurement traceability is maintained when paired with metrology-grade picoammeters meeting IEC 61000-4-30 Class A accuracy requirements.

Software & Data Management

The FC-86 functions as a passive transduction element and does not include embedded firmware or onboard data acquisition. It is fully compatible with industry-standard electrometer platforms—including Keysight B2987A, Keithley 6430, and Zurich Instruments HF2LI—enabling synchronized current logging, time-resolved beam profiling, and integration into LabVIEW™, Python (PyVISA), or MATLAB® control frameworks. When deployed in GLP- or GMP-regulated environments, raw current data streams may be routed through validated DAQ systems supporting 21 CFR Part 11-compliant audit trails, electronic signatures, and secure data archiving. Optional analog voltage output (0–10 V, scalable to ±1 V full-scale) facilitates direct interfacing with PLCs or oscilloscopes for real-time process monitoring.

Applications

• Quantitative beam current normalization in electron microscopy (SEM/FIB) source optimization and stability testing.
• In-situ dosimetry during ion implantation process development and endpoint detection in semiconductor fabrication.
• Calibration reference for beam position monitors (BPMs) and secondary electron detectors in synchrotron beamlines and free-electron laser (FEL) facilities.
• High-power electron beam welding and additive manufacturing system validation, where thermal load distribution and current stability directly impact part density and microstructure.
• Spacecraft propulsion thruster testing (e.g., Hall-effect and gridded ion thrusters), requiring accurate thrust-to-power correlation via beam current measurement.

FAQ

What vacuum compatibility does the FC-86 support?
The FC-86 is rated for continuous operation in UHV conditions down to 1×10⁻⁹ Torr and includes all-metal seals compatible with bake-out temperatures up to 200 °C.
Can the FC-86 measure pulsed beams?
Yes—its low-inductance design and shielded signal path support pulse widths ≥100 ns with rise times <50 ns when used with appropriate fast-response electrometers.
Is the fluorescent screen included with every unit?
Yes, the removable YAG:Ce or P43 phosphor screen is standard equipment and installed on a precision kinematic mount for repeatable alignment.
Does Kimball Physics provide calibration documentation?
Each FC-86 ships with a Certificate of Conformance detailing dimensional verification, material certifications, and vacuum leak test results; NIST-traceable current calibration requires external electrometer validation.
What cooling water specifications are recommended?
Deionized water at 18–22 °C, flow rate ≥2.5 L/min, and pressure ≤60 psi is recommended to maintain thermal equilibrium at maximum rated power.