Abstract

The utilization of polarized targets in scattering experiments has become a common practice in many major accelerator laboratories. Noble gases are especially suitable for such applications, since they can be easily hyper-polarized using spin exchange or metastable pumping techniques. Polarized helium-3 is a very popular target because it often serves as an effective polarized neutron due to its simple nuclear structure. A favorite cell material to generate and store polarized helium-3 is GE-180, a relatively dense aluminosilicate glass. In this paper, we present a Faraday rotation method, using a new triple modulation technique, where the measurement of the Verdet constants of SF57 flint glass, pyrex glass, and air was tested. The sensitivity obtained shows that this technique may be implemented in future cell wall characterization and thickness measurements. We also discuss the first ever extraction of the Verdet constant of GE-180 glass for four wavelength values of 632 nm, 773 nm, 1500 nm, and 1547 nm, whereupon the expected 1/λ2 dependence was observed.

Document Type

Article

Publication Date

7-2015

Notes/Citation Information

Published in Review of Scientific Instruments, v. 86, no. 7, article 073107, p. 1-4.

Copyright 2015 AIP Publishing. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.

The following article appeared in Review of Scientific Instruments, v. 86, no. 7, article 073107, p. 1-4 and may be found at http://dx.doi.org/10.1063/1.4926459.

Digital Object Identifier (DOI)

http://dx.doi.org/10.1063/1.4926459

Funding Information

This work was supported by the Department of Energy Award No. DE-FG02-99ER41101.

1.eps (490 kB)
Fig. 1 High-Res: Schematic of the triple modulation setup, which includes a linear polarizer, Helmholtz coils with an applied sinusoidal magnetic field, PEM, second linear polarizer, optical chopper, and detector. LabVIEW was used to control the magnetic field and to collect the data. The G-Iron/Metglas magnetic shielding was implemented to eliminate any magnetic fringe fields.

Figure 1.pptx (65 kB)
Fig. 1 Powerpoint: Schematic of the triple modulation setup, which includes a linear polarizer, Helmholtz coils with an applied sinusoidal magnetic field, PEM, second linear polarizer, optical chopper, and detector. LabVIEW was used to control the magnetic field and to collect the data. The G-Iron/Metglas magnetic shielding was implemented to eliminate any magnetic fringe fields.

2.eps (152 kB)
Fig. 2 High-Res: Plot of the Verdet vs. λ for the 4 mm GE-180 sample from NIST.

Figure 2.pptx (45 kB)
Fig. 2 Powerpoint: Plot of the Verdet vs. λ for the 4 mm GE-180 sample from NIST.

Table I.JPG (45 kB)
Table 1: The measured Verdet constant of SF57 flint glass and pyrex glass for various λ, with air corrections applied.

Table II.JPG (35 kB)
Table II: Measured Verdet constant of air for various λ.

Table III.JPG (38 kB)
Table III: The measured Verdet constant of the NIST GE-180 sample for various λ, with the air corrections applied.

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