Dk and Df are both terms used in the field of electrical engineering to describe the electrical properties of materials, specifically their ability to store and transmit electrical energy.

Dk, also known as dielectric constant or relative permittivity, is a measure of a material’s ability to store electrical energy in an electric field. It is a dimensionless quantity that describes how much a material’s electric field is reduced when it is placed between two charged plates. A higher Dk means that the material can store more electrical energy and is therefore a better insulator.

The dielectric constant of high-purity fused silica, as used by ED2 Corporation, typically falls in the range of 3.7 to 3.9. This value can vary slightly depending on factors such as the exact composition and processing of the silica material. Fused silica is a type of glass with very low impurities, and it is often used in applications where a high dielectric constant and low electrical conductivity are desirable, such as in optics, electronics, and telecommunications.

Df, also known as the loss tangent, is a measure of a material’s ability to dissipate electrical energy as heat when it is exposed to an alternating electric field. It is the tangent of the phase angle between the voltage and the current in a circuit. A higher Df means that the material dissipates more electrical energy and is therefore a poorer insulator.

In summary, Dk and Df are both important electrical properties of materials, with Dk describing a material’s ability to store electrical energy, and Df describing a material’s ability to dissipate electrical energy.