Open AccessAdvanced field‐measurement method with three orthogonal Hall probes for an elliptically polarizing undulator
Author(s) -
Hwang C.S.,
Fan T. C.,
Lin F. Y.,
Yeh Shuting,
Chang C. H.,
Chen H. H.,
Tseng P. K.
Publication year - 1998
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049597013691
Subject(s) - undulator , elliptical polarization , physics , field (mathematics) , optics , laser , linear polarization , mathematics , pure mathematics
A three‐orthogonal‐Hall‐probe assembly with an `on the fly' mapping method has been developed to characterize an elliptically polarizing undulator (EPU). The underlying design concept is that it can measure the three real field components without any field correction under a reliable and synchronization measurement method. Therefore, the relative central position shift, orthogonal angle and the planar Hall effect error between the three Hall probes should be calibrated and readjusted. Experimental results demonstrate that this method can yield an r.m.s. reproducibility of 10 G cm for the three field components and 2 G for the peak field strength. Under precision conditions this system can completely measure the three on‐axis field components within 2 min for a 4 m‐long EPU.