Government_Requirements_Final_.pdf

Government Requirements

I. BACKGROUND INFORMATION

The National Institute of Standards and Technology’s Materials Science and Engineering Division (MSED) is developing “Thermal MagIC”, an SI-traceable method for 3D thermal magnetic imaging and control. As part of our work, we are developing the characterization methods for all parts of the system, from the magnetic nano-objects to the imaging instrumentation, which requires sensitive instrumentation for measuring the magnetic properties as a function of applied magnetic field and temperature. Specifically, the purpose of this procurement is to acquire high purity Litz wire that can operate at high frequencies (>2.8 MHz) for development of quantitative instrumentation.

II. SCOPE OF WORK

The contractor shall provide two different high purity, high frequency Litz wires, one for low current and the other for high current.

III. SPECIFICATIONS

Litz wire consists of many individually insulated copper wires twisted in a uniform bundle, where each strand spends equal measure at the outside periphery of the conductor and at its center. Bundles can then be twisted together to form a larger bundle, for increased current capacity. This unique twisting method, plus carefully selected wire diameter, gives Litz wire the ability to minimize losses from skin effect and proximity effect.

For this application, high purity is essential, as the iron impurities in the copper wire raise the background signal of the instrument by two orders of magnitude. The two (2) high purity, high frequency Litz wire must both satisfy the following base requirements as well as the specified current/voltage/outer diameter limitations for low current operation (wire #1) and high current operation (wire #2):

Base Requirements for both types:

• Operating temperature range: 4.2 K to 400 K

• Operating frequency range: DC up to 2.8 MHz or greater (specify upper limit)

• Copper wire purity: 99.99% or better

• Insulator: polyimide or other material without iron impurities and capable of being thermally cycled from

4.2 K many times

• Minimum length: 1000 ft, Low Current Litz Wire:

• Maximum operating voltage: 10 V at all frequencies/temperatures

• Outer Diameter: 0.5 mm or smaller

• Specify maximum current range

High Current Litz Wire:

• Maximum operating current: 7 A at all frequencies/temperatures

• Specify outer diameter

Warranty:

The Contractor shall provide, at a minimum, a one-year warranty for the Litz wire. The warranty shall cover all material and shipping costs. The warranty shall commence upon receipt and demonstration of all required specifications.

IV. DELIVERY DATE

The delivery date shall be six (6) months from award of this requirement.

V. PLACE OF DELIVERY

All work shall be completed at the Contractor’s facility.

VI. DELIVERABLES

Description

Quant ity Due Date Low current, high purity, high frequency Litz wire At least 1000 feet

6 months after award of this requirement High current, high purity, high frequency Litz wire At least 1000 feet

VII. ACCEPTANCE CRITERIA

The Government will inspect that all minimum specifications are met. (NIST employee would be available for testing at manufacturer prior to shipment, if necessary.)