Heater System Magnetic Field Suppression via Segmented Current Leads

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Solution Overview

Problem

Electromagnetically sensitive temperature-controlled environments, such as NMR and alkali vapor magnetometers, are vulnerable to spurious magnetic fields generated by heater systems, which can exceed their magnetic tolerance and affect measurement accuracy.

Innovation Solution

A heater system with magnetic field suppression is designed, utilizing a current source and heater with current lead wires arranged on separate substrate layers to split and conduct input and return currents, thereby reducing the amplitude of magnetic fields generated, and mitigating their impact on spin-based detection systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional heater systems with simple current lead wires are used, then the device complexity is low, but spurious magnetic fields are generated that exceed magnetic tolerance and affect measurement accuracy

Engineering Contradiction:
Improvemeasurement accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The current lead wire system is segmented into multiple separate substrate layers, with each layer carrying a portion of the return current. This segmentation distributes the magnetic field generation across multiple spatial locations, enabling cancellation effects that reduce the net spurious magnetic field at the sensor while maintaining manageable device complexity through modular layering.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If current lead wires are arranged on separate substrate layers to suppress magnetic fields, then spurious magnetic fields are reduced, but the device complexity increases due to multiple layers and routing

Engineering Contradiction:
Improvespurious magnetic fieldsVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The solution transitions from a planar two-dimensional wire arrangement to a three-dimensional multi-layer substrate structure. By distributing current lead wires across multiple substrate layers stacked in the vertical dimension, the magnetic fields from adjacent wires can cancel each other more effectively, reducing spurious fields while the modular layering manages the complexity through standardized stacking.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If multiple current lead wires on separate layers are used to divide and conduct currents, then magnetic field suppression is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improvemagnetic field amplitudeVSAvoidease of manufacture
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

Each substrate layer serves multiple functions: it provides mechanical support, electrical insulation, and current conduction pathways. The standardized multi-layer structure can be manufactured using conventional PCB or semiconductor fabrication techniques, making the magnetic field suppression capability achievable through existing manufacturing processes rather than requiring specialized assembly methods.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively mitigates the effects of spurious magnetic fields on alkali metal vapor precession in NMR sensors, enhancing measurement accuracy by reducing residual magnetic fields and maintaining precise temperature control.

Implementation Method 1

a heater configured to generate heat in response to the input current

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

spurious magnetic fields generated by heater systems

Methodology Applied
Scientific EffectElectromagnetic field generation: Electromagnetic Induction

Data Source

PatentEP3848716B1Heater system with magnetic field suppression
Publication Date: 2022.10.19 NORTHROP GRUMMAN SYSTEMS CORP
  • EP3848716B1 patent drawingFigure 1~3
  • EP3848716B1 patent drawingFigure 4~5
  • EP3848716B1 patent drawing

AI summary

One embodiment includes a heater system. The system includes a current source configured to generate an input current and to receive a return current. The system also includes a heater configured to generate heat in response to the input current. The system further includes a plurality of current lead wires interconnecting the current source and the heater and being configured to provide the input current to the heater and to conduct the return current from the heater. Each of the plurality of current lead wires is arranged on a separate substrate layer such that each of the plurality of current lead wires are each spaced apart from each other. At least one of the input current and the return current is divided to be conducted on two or more of the plurality of current lead wires.