The Space Infrared Interferometric Telescope (SPIRIT): High-resolution imaging and spectroscopy in the far-infrared

We report results of a recently-completed pre-Formulation Phase study of SPIRIT, a candidate NASA Origins Probe mission. SPIRIT is a spatial and spectral interferometer with an operating wavelength range 25 - 400 microns. SPIRIT will provide sub-arcsecond resolution images and spectra with resolution R = 3000 in a 1 arcmin field of view to accomplish three primary scientific objectives: (1) Learn how planetary systems form from protostellar disks, and how they acquire their inhomogeneous composition; (2) characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different types form; and (3) learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. Observations with SPIRIT will be complementary to those of the James Webb Space Telescope and the ground-based Atacama Large Millimeter Array. All three observatories could be operational contemporaneously.Comment: 20 pages, 12 figures, accepted for publication in J. Adv. Space Res. on 26 May 200

The Origin of the Universe as Revealed Through the Polarization of the Cosmic Microwave Background

Modern cosmology has sharpened questions posed for millennia about the origin of our cosmic habitat. The age-old questions have been transformed into two pressing issues primed for attack in the coming decade: How did the Universe begin? and What physical laws govern the Universe at the highest energies? The clearest window onto these questions is the pattern of polarization in the Cosmic Microwave Background (CMB), which is uniquely sensitive to primordial gravity waves. A detection of the special pattern produced by gravity waves would be not only an unprecedented discovery, but also a direct probe of physics at the earliest observable instants of our Universe. Experiments which map CMB polarization over the coming decade will lead us on our first steps towards answering these age-old questions

JET experience on managing radioactive waste and implications for ITER

The reduced radiotoxicity and half-life of radioactive waste arisings from nuclear fusion reactors as compared to current fission reactors is one of the key benefits of nuclear fusion. As a result of the research programme at the Joint European Torus (JET), significant experience on the management of radioactive waste has been gained which will be of benefit to ITER and the nuclear fusion community.The successful management of radioactive waste is dependent on accurate and efficient tracking and characterisation of waste streams. To accomplish this all items at JET which are removed from radiological areas are identified and pre-characterised, by recording the radiological history, before being removed from or moved between radiological areas. This system ensures a history of each item is available when it is finally consigned as radioactive waste and also allows detailed forecasting of future arisings. All radioactive waste generated as part of JET operations is transferred to dedicated, on-site, handling facilities for further sorting, sampling and final streaming for off-site disposal. Tritium extraction techniques including leaching, combustion and thermal treatment followed by liquid scintillation counting are used to determine tritium content.Recent changes to government legislation and Culham specific disposal permit conditions have allowed CCFE to adopt additional disposal routes for fusion wastes requiring new treatment and analysis techniques. Facilities currently under construction include a water de-tritiation facility and a materials de-tritiation facility, both of which are relevant for ITER. The procedures used to manage radioactive waste from generation to off-site disposal have been assessed for relevance to ITER and a number have been shown to be significant. The procedures and de-tritiation factors demonstrated by radioactive waste treatment plants currently under construction will be important to tritium recovery and waste minimisation in ITER and DEMO