NEWS

Fourth Printing

A fourth printing will be released by Oxford University Press the summer of 2011.  Several typographical corrections have been made, as well as a few updates to the appendix data.  These are annotated in the Errata section of this web site, and incorporated into the posted data tables (English version). 

Scaling Law review paper published (Chapter 10)

An invited review paper has been published that provides further information on the background and use of the scaling laws described in Chap. 10.  This supersedes the book’s previous reference “Ekin, J. W. (2007) Cryogenics, to be published”: 

Ekin, J. W. (2010).  “Unified scaling law for flux pinning in practical superconductors: 1. Separability postulate, raw scaling data and parameterization at moderate strains,” Supercond. Sci. Technol. 23, 083011. 

Data tables translated into Chinese

Tables have been translated into Chinese by Dr. Xi Chuanying with technical assistance from Dr. Bruce Brandt.

Appendix data (71 tables)

All the cryogenic materials and design data from the book's appendix are now posted and accessible from the links in the left column. After opening the appendix data file, use control+F to quickly search and find information.

Third Printing

The first two printings sold out and a third printing was made in 2007.

Second Printing

January 23, 2007: Good news. The first printing has sold out and Oxford is now in the process of a second print run for the book.

Parameter-value update

I used the opportunity of the second printing to update one of the recommended parameter values in the Unified Scaling Law, the temperature exponent for Nb3Sn superconductors. As noted several times in the text, this is perhaps the least well characterized scaling parameter (because relatively few variable-temperature, high-current measurements are available at present). Based on recent papers by Goodrich and by Godeke that have appeared since the first printing was submitted for publication, the data suggest that a more representative general value for to use with the Unified Scaling Law would be 2.5 (rather than 3 as used in the first printing).

In practice, the parameter is expected to vary for different superconductor types and further data will be needed in order to tabulate recommended values for different classes of superconductors, but this value should serve well for accurately transforming available critical current data to nearby temperatures using the transformation technique described in Sec. 10.7.5. The effective critical temperature to use as a general representative value for Nb3Sn samples has also been updated to 17 K (instead of 17.5 K given in the first printing). These two changes have been incorporated in the example calculation given in Sec. 10.7.5 and most notably in the summary of parameter values given in Appendix A10.2a on p. 616.

As emphasized in the text, the separable parameter set employed in the text’s examples is useful for predicting changes in the critical current of practical wires for engineering applications. The separability feature is especially useful for updates such as this, since it allows temperature and strain parameter values to be updated independently of each other, without changing the values of the rest of the parameter set. As additional data become available for individual classes of superconductors, we should be able to further update the parameter values tabulated in Appendix A10.2a for calculating critical-currents variations with temperature and strain.