Opacity measurements of tamped NaBr samples heated by z-pinch X-rays

Laboratory measurements provide benchmark data for wavelength-dependent plasma opacities to assist inertial confinement fusion, astrophysics, and atomic physics research. There are several potential benefits to using z-pinch radiation for opacity measurements, including relatively large cm-scale lateral sample sizes and relatively-long 3-5 ns experiment durations. These features enhance sample uniformity. The spectrally resolved transmission through a CH-tamped NaBr foil was measured. The z-pinch produced the X-rays for both the heating source and backlight source. The (50 +/- 4) eV foil electron temperature and (3 +/- 1) x 10(21) cm(-3) foil electron density were determined by analysis of the Na absorption features. LTE and NLTE opacity model calculations of the n = 2 to 3, 4 transitions in bromine ionized into the M-shell are in reasonably good agreement with the data. (C) 2003 Elsevier Science Ltd. All rights reserved.