Erratum
In Arthur L. Robinson's article "Berkeley advanced materials center OK'd" (Research News, 18 Feb., p. 827), a line was omitted in the first column of page 828. The second sentence in the second paragraph should have read, "Synchrotron radiation sources are evolving rapidly. The ALS will be the first of the third generation of sources in which most, if not all, the synchrotron radiation comes from special magnets with the generic name `insertion devices,' rather than from the dipole bending magnets that keep the electron beam in its approximately circular orbit."