ABSTRACT
The fusion diagnostic community, including the National Ignition Facility, the Laboratory for Laser Energetics, Megajoule in France, and others require optical recording instruments with precise time resolution covering a dynamic range of many orders of magnitude. In 2012, LLE, Photek, and Sydor Instruments embarked on the re-design of an improved streak tube for fusion diagnostics. As a baseline we started with the Photek ST-Y streak tube which is a member of the RCA design dating back to 1957, because the tube body can accommodate a 35 mm long photocathode, and consequently more fibre coupled diagnostic channels than smaller designs. Electron optical modelling was carried out by both Paul Jaanimagi in the US and by Photek with different software packages in a parallel exercise. Our goal was to address some of the short-comings of this tube, the initial approach being to increase the field between the photocathode and extractor electrode from 700 to 1300 V/mm to reduce space charge effects and to improve time resolution. Many changes and modifications were made: the time resolution was improved to 5 ps, the usable cathode length was increased from 20 mm to 32 mm under high extraction field operation, and the off-axis spatial resolution was substantially improved compared to other tubes of this format. Several tubes have been built and tested in Sydor ROSS-5800 streak cameras.
ABSTRACT
PURPOSE: This study was designed to test the feasibility of conducting routine quality assessment within community medical oncology practices. DESCRIPTION OF STUDY: Eleven medical oncologists practicing within the Fox Chase Network were surveyed over an 8-month period, using a standardized 10-item checklist. Eight of the items (ie, board certification, continuing education, office procedure manual for chemotherapy, chemotherapy flow sheets, body surface area calculations, adherence to guidelines for follow-up of breast cancer, adjuvant hormones in women with estrogen receptor-positive breast cancer, and patient satisfaction survey) were chosen because they measure structural and process variables particularly relevant to the high-volume clinical services seen in private practice oncology. The authors also calculated two rates (protocol accrual and neutropenic complications of chemotherapy) to test as putative indicators of quality. RESULTS: The authors found a high level of both physician interest in developing the audit measures and compliance with the survey process. Overall quality of care, as measured by structure and process variables, was excellent with negligible internal variability. Derived rates of protocol accrual (0.003-0.373; mean 0.11, SD 0.11) and neutropenic sepsis (0.004-0.014; mean 0.007, SD 0.004) show considerable variability, however, and are only minimally correlated (r= -.36). These are both potential indicators of quality that should be further evaluated. CLINICAL IMPLICATIONS: The authors have demonstrated the feasibility of conducting quality assessment within private medical oncology practices and have identified two easily calculated rates that merit further study as potential indicators of quality.
