Advanced Composite Laminates for Forming High Temperature Superconducting Magnetic Shields

PSI proposed to develop a novel method for making large high temperature superconducting magnetic shields. There are many existing applications that need the high level of electro-magnetic isolation that is obtained with superconducting magnetic shields. For example, atomic frequency standards, biomagnetic measurement systems, and SQUID based devices could benefit from the availability of large, low cost superconducting magnetic shields. Low temperature superconducting magnetic shields, which operate at liquid helium temperatures (4.2), offer extremely high levels of shielding, but require expensive cryogenic systems to maintain teh required operating temperatures. High temperature superconducting (HTS) shields, which can operate at liquid nitrogen temperatures (77 K), require relatively simple and inexpensive cryogenic systems and the shielding level obtained with HTS shields is greater than can be obtained with pre-existing 77 K shielding technology. However, with current state-of-the-art techniques, HTS magnetic shields are difficult to construct in sizes large enough for many applications. PSI has developed an innovative process by which small HTS magnetic shields have been easily construction and tested. We propose to extend and optimize this process for the construction of large magnetic shielding structures. In the process we form multi-layer ceramic metal laminates; usually a metal-HTS-metal sandwich. These composite sheets are formed into magnetic shields by deep drawing. The shields created by this process can be easily manufactured, handled and incoporated into cryostats. Anticipated Benefits: Magnetic shields made by the proposed technique will find application in devices where high levels of magnetic shielding are critical, such as frequency standards and devices that use HTS SQUIDS. The proposed process is well suited for large scale manufacturing.