Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Intimate Partner Violence and HIV Risks: A Longitudinal Study of Men on Methadone

Whereas research has suggested that drug-involved men are at disproportionately high risk of engaging in transmission risk behaviors for HIV and of perpetrating intimate partner violence (IPV) against women, only a few cross-sectional studies have examined the relationship between IPV and HIV/sexually transmitted infection (STI) transmission risks among heterosexual, drug-involved men. This study builds on previous cross-sectional research by using a longitudinal design to examine the temporal relationships between perpetration of IPV and different HIV/STI transmission risks among a random sample of 356 men on methadone assessed at baseline (wave 1), 6 months (wave 2), and 12 months (wave 3). The findings indicate that (1) perpetration of IPV in the past 6 months at wave 1 was associated with having more than one intimate partner, buying sex, and sexual coercion at subsequent waves and that (2) noncondom use, injecting drugs, and sexual coercion at wave 1 were associated with subsequent IPV. The temporal relationships between perpetration of IPV and HIV risks found in this study underscore the need for HIV prevention interventions targeting men on methadone to consider IPV and HIV risks as cooccurring problems