[en] We present a one-port calibration technique for characterization of beam waveguide components with a vector network analyzer. This technique involves using a set of known delays to separate the responses of the instrument and the device under test. We demonstrate this technique by measuring the reflected performance of a millimeter-wave variable-delay polarization modulator.

[en] The decays of ¹⁵²Eu^m,g→¹⁵²Sm have been studied by γ-ray spectroscopy using the 8π spectrometer, an array of 20 Compton-suppressed Ge detectors. Very weak γ-decay branches in ¹⁵²Sm were investigated through γ-γ coincidence spectroscopy. All possible E2 transitions between states below 1550 keV with transition energies >130 keV are observed, including the previously unobserved 2₃⁺→0₂⁺ 401 keV transition. The results, combined with existing lifetime data, provide a number of new or revised E2 transition strengths which are critical for clarifying the collective structure of ¹⁵²Sm and the N=90 isotones

[en] Variable-delay Polarization Modulators (VPMs) are currently being implemented in experiments designed to measure the polarization of the cosmic microwave background on large angular scales because of their capability for providing rapid, front-end polarization modulation and control over systematic errors. Despite the advantages provided by the VPM, it is important to identify and mitigate any time-varying effects that leak into the synchronously modulated component of the signal. In this paper, the effect of emission from a 300 K VPM on the system performance is considered and addressed. Though instrument design can greatly reduce the influence of modulated VPM emission, some residual modulated signal is expected. VPM emission is treated in the presence of rotational misalignments and temperature variation. Simulations of time-ordered data are used to evaluate the effect of these residual errors on the power spectrum. The analysis and modeling in this paper guides experimentalists on the critical aspects of observations using VPMs as front-end modulators. By implementing the characterizations and controls as described, front-end VPM modulation can be very powerful for mitigating 1/f noise in large angular scale polarimetric surveys. None of the systematic errors studied fundamentally limit the detection and characterization of B-modes on large scales for a tensor-to-scalar ratio of r = 0.01. Indeed, r < 0.01 is achievable with commensurately improved characterizations and controls