We have developed a hybrid Ti:sapphire-Nd:glass laser system that produces more than 1500 TW (1.5 PW) of peak power. The system produces 660 J of power in a compressed 440+/-20 fs pulse by use of 94-cm master diffraction gratings. Focusing to an irradiance of >7x10(20) W/cm (2) is achieved by use of a Cassegrainian focusing system employing a plasma mirror.

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the AFFIRM Investigators* Background-Expectations that reestablishing and maintaining sinus rhythm in patients with atrial fibrillation might improve survival were disproved in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study. This report describes the cause-specific modes of death in the AFFIRM treatment groups. Methods and Results-All deaths in patients enrolled in AFFIRM underwent blinded review by the AFFIRM Events Committee, and a mode of death was assigned. In AFFIRM, 2033 patients were randomized to a rhythm-control strategy and 2027 patients to a rate-control strategy. During a mean follow-up of 3.5 years, there were 356 deaths in the rhythm-control patients and 310 deaths in the rate-control patients (Pϭ0.07). In the rhythm-control group, 129 patients (9%) died of a cardiac cause, and in the rate-control group, 130 patients (10%) died (Pϭ0.95). Both groups had similar rates of arrhythmic and nonarrhythmic cardiac deaths. The numbers of vascular deaths were similar in the 2 groups: 35 (3%) in the rhythm-control group and 37 (3%) in the rate-control group (Pϭ0.82). There were no differences in the rates of ischemic stroke and central nervous system hemorrhage. In the rhythm-control group, there were 169 noncardiovascular deaths (47.5% of the total number of deaths), whereas in the rate-control arm, there were 113 noncardiovascular deaths (36.5% of the total number of deaths) (Pϭ0.0008). Differences in noncardiovascular death rates were due to pulmonary and cancer-related deaths. Conclusions-Management of atrial fibrillation with a rhythm-control strategy conferred no advantage over a rate-control strategy in cardiac or vascular mortality and may be associated with an increased noncardiovascular death rate.

K1J 953, tel# (613) 744-3530 Failure Mechanism Dimensional Discrepancies Overrolling of Debris Corrosion Other FatigueAbsrrucr-The development of an in-line, full flow oil debris sensor for aircraft engine condition assessment is described. First used on the F22 fighter, this sensor is the only " all-metals" debris detector in production. The sensor is based on an inductive measurement technique which enables the system to detect, count and classify wear metal particles by size and type (ferromagnetic and nonferromagnetic) above a minimum particle size threshold. In flight, the measured count values are compared to preset levels to provide prognostic health information on the oilwetted components of the engine. This paper describes the sensor design requirements, principle of operation, electronic design and mechanical design features. The results of a test program established to correlate the oil borne debris measurements to component degradation characteristics and data from actual engine bearing failures, are also presented. FrequencyObserved (%) 29 24 35 10 2

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