Development of diagnostics for high-energy petawatt pulses

Applications accessed by high energy petawatt (HEPW) lasers require complete, single-shot characterization of pulse spatial, temporal, and energy characteristics. We describe techniques that enable single-shot characterization of the temporal shape and pulse contrast of HEPW pulses with >10{sup 8} dynamic range over a ns-temporal window. Approaches to measure pulse durations that span two orders of magnitude will be discussed. Finally, we describe a novel implementation of spectrally dispersed two-beam interferometry for measurement of the phase difference between two HEPW pulses. This technique can be applied to dispersion and B-integral measurements in a HEPW system, as well as to achieve precise timing of nanosecond pulses. Lastly, spectrally dispersed interferometry represents an ideal technique to enable coherent addition of HEPW pulses for production of ultrahigh intensities

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

Gender Identity Issues and Workplace Discrimination: The Transgender Experience

Mainstream social constructions of gender tend to demand conformity by adhering to only two choices of gender identity, male and female. Transgender individuals transgress this binary conception of gender by deviating from the societal gender norms associated with the sex assigned at birth. Using a combination of face-to-face and phone interviews to collect data, twenty-six interviews were conducted with male-identified transgender individuals aged 18 to 57 from throughout the United States. All participants were born female bodied but eventually expressed gender traits that align with male identity rather than female identity. The participants were recruited using purposive and snowball sampling techniques. Our findings reveal the workplace experiences of a sample of female-to-male (FTM) individuals and provide accounts of how male-identified transgender individuals negotiate their gender identities within the workplace and deal with the issues that arise as a result