Electrical and optical measurements on the first SCUBA-2 prototype 1280 pixel submillimeter superconducting bolometer array.

SCUBA-2 is a submillimeter camera being built for the James Clerk Maxwell Telescope in Hawaii. Bringing CCD style imaging to the submillimeter for the first time, with over 10000 pixels, it will provide a revolutionary improvement in sensitivity and mapping speed. We present results of the first tests on a prototype 1280 pixel SCUBA-2 subarray; the full instrument will be made up of eight such subarrays. The array is made up of transition edge sensor (TES) detectors, with Mo/Cu bilayers as the sensing element. To keep the number of wires reasonable, a multiplexed readout is used. Unlike previous TES arrays, an in-focal plane multiplexer configuration is used, in which the multiplexing elements are located beneath each pixel. To achieve the required performance, the detectors are operated at a temperature of approximately 120 mK. We describe the results of a basic electrical and optical characterization of the array, demonstrating that it is fully operational. Noise measurements were made on several pixels and gave a noise equivalent power below 2.5 x 10(-17) W HZ(-0.5), within the requirements for SCUBA-2. The construction of the testbed used to carry out these measurements is also described.

Secondary prevention for coronary heart disease: a qualitative study.

The many responsibilities of primary care, cardiac rehabilitation and secondary prevention of coronary heart disease is a growing concern. Demanding standards have been given to primary care in the National Service Framework for Coronary Heart Disease. This article reports an evaluation of an intervention to support primary care service providers in this responsibility. A part-time specialist nurse and a part-time exercise worker were appointed to work in a group of 11 GP practices in a primary care trust in a city in the north of England. The evaluation component reported here is a qualitative study of the perceptions of health professionals on secondary prevention of coronary heart disease. Interviews were conducted with 18 primary care staff from practices in both intervention (n = 11) and control (n = 11) groups. The evaluation revealed support for the development of nurse-led clinics, increased confidence and skills development among practice nurses, but some concern about competing demands on practice nurses' time. Primary healthcare professionals found their resources stretched by competing demands on their time from government initiatives.