Differential Integrators for Magnetic Diagnostics

EHT integrators are designed to simplify magnetic field measurements. Pickup coils are widely used in plasma physics and fusion science for precise measurement of magnetic fields. The voltage across the coil is proportional to the time derivative of the field. Analog integrators produce an output signal that is equal to the integral of the input signal. These off-the-shelf integrators remove the complexity of making stable integrators so you can conduct your science and not re-invent the electronics.

EHT analog differential integrators measure the strength of a magnetic field by calculating the integral of the voltage generated by the coils.

Best In Class

The EHT integrators significantly exceed the highest specifications for drift error, run time, common mode rejection, integration error, and pulse duration. They are “best of class” in the world.

Very High Currents. No Maximum Field Strength. Indefinite Duration

Typical current monitors (transformers) often suffer from droop and saturation problems. These are absent with air core coils, thus the EHT integrators can measure very large currents, for very long times, with high precision. There is no inherent limit to the current or field size that can be measured.

High Precision In Very Small And Very Large Fields

With extraordinarily high precision, the EHT integrators measure both extremely small fields and extremely large fields.

Consider this setup: 100 turns wound around 300 mm diameter ferrite, making a loop with an area of 0.1 square metres. With a relative permeability of 1000 in a 100 pT field, the EHT integrator will produce a 1 mV output. Small air core pickup coils would be used to measure medium to large fields.

Operation From Nano-Seconds To Continuous

The EHT ultra stable analog integrators can measure bursts from 100 nanoseconds to continuous operation, at frequencies up to 5 MHz, and with low output impedance.

Unprecedented Effective Dynamic Range

Due to their extremely high gain and high frequency of operation, EHT integrators have an extremely wide effective dynamic range.

Consider a 1000 second square wave input signal. Using a 12 bit digitizer, the EHT integrator will produce a signal with 100 ns precision over time (temporal resolution) post-processed, and 22 bits of dynamic range information. Thus extreme detail for high frequencies can be resolved for very large and slow signals.

Options: Input Impedance, RC Time Constant, And Connectors

Input impedance is user selected based on the application in the range between 50 Ω to 100 kΩ, and then set at the factory. Similarly, RC time constant is user selected and factory set between 1 µs to 100 ms. I/O options will match many types of DAQ and control systems, and include RJ45, BNC, and SCSI. The integrators are delivered in a 1U rack-mount chassis.

Variants

8 And 16 Channel.

Applications

The 16-channel “Integrator Short Pulse” and the 8-channel “Integrator Long Pulse” from Eagle Harbor Technologies (EHT) are ultra stable, high frequency, analog differential integrators.

Analog integrators produce an output signal that is equal to the integral of the input signal. They are used for magnetic field measurements, current measurements, analog voltage integration, and the EHT ILP-8 is well suited to extreme applications, such as nuclear fusion in-vessel diagnostics.