While electron beam lithography (EBL) tools may not require magnetic environments with fields in the nanoTesla regime any time soon, EBL equipment vendors may well learn a few tricks from the physics community. Over the last few years, a group centered on the physics department at TU München have developed extraordinary shielded environments, along with efficient degaussing methods. In a publication today, they report achieving a factor of 106 damping at mHz frequencies.
The record-breaking apparatus consists of a shielded room with a removable shielding insert. Within the insert’s 10 m3 volume, the team reports a residual magnetic field of < 0.3 nT along with the above damping factor.
The paper usefully includes a section of observations regarding shield design.
“A large-scale magnetic shield with 106 damping at millihertz frequencies”, http://dx.doi.org/10.1063/1.4919366; see also arXiv:1501.07861
“A magnetically shielded room with ultra low residual field and gradient”, http://dx.doi.org/10.1063/1.4886146; see also arXiv:1403.6467
“Minimizing magnetic fields for precision experiments”, arXiv:1502.07408