The operation of high-power and high-repetition-rate laser systems is commonly disrupted by the failure of optical components. Optical coatings in vacuum systems accumulate laser-induced contamination (LIC) and are damaged afterward. Currently, only active LIC mitigation methods involving plasma cleaning or oxygen injection in the system are used, which require additional interventions and can disrupt the regular operation. The presented investigation aims to study the multilayer coating design influence on the formation of LIC for dielectric high-reflectivity Bragg mirrors. The manipulation of electric field enhancement on the surface and the material of the last layer revealed that silica tends to accumulate more surface contamination than hafnia materials. Also, the size of the affected area linearly depends on the strength of the E-field at the coating surface. These findings suggest that optimizing coating design - specifically by controlling the E-field distribution and top-layer material - can minimize LIC growth, potentially extending the lifespan of optical components in high-power laser applications, including space and industrial systems.

High-power laser-matter interaction and the related high-energy density physics (HEDP) are two important topics in modern physics. However, for decades, a very restrictive limitation prevents researchers from studying these topics efficiently: nanosecond-kilojoule class lasers are typically characterized by a low repetition rate ( & AP; -1) that restricts the data acquisition and limits the available statistics for analysis. Here, we describe the first results obtained using the high-repetition rate nanosecond-kilojoule (L4n laser beamline) experimental platform commissioned at the Extreme Light Infrastructure-Beamlines. We proved the capability to deliver hundreds of joules shots every three min with a very good repeatability. Using high-resolution x-ray spectroscopy, we studied highly resolved spectra of H-like and He-like Cl lines emitted from polyvinyl chloride targets and demonstrated that the plasma parameters (electron temperature and density) derived from the measured spectra are consistent with hydro-simulations. These results demonstrate the fulfillment of the designed platform performance which should become one of the most important assets for the HEDP community in the following decades.

AbstractUnsustainable hunting, both illegal and legal, has led to the extirpation of many species. In the last 35 years giraffeGiraffaspp. populations have declined precipitously, with extinctions documented in seven African countries. Amongst the various reasons for these population declines, poaching is believed to play an important role in some areas. Giraffes are primarily hunted for consumption and for the use of their body parts as trophies and in traditional medicine. However, the socio-economic factors that correlate with the use of giraffe body parts are not well understood. We conducted our study in Tsavo Conservation Area, Kenya, which experiences high levels of poaching. We used semi-structured surveys amongst 331 households to document how giraffe body parts are typically acquired and their intended use (i.e. trophy, medicinal or consumptive). We then used logistic regression models to assess the correlations between nine socio-economic factors and the use of giraffe body parts. We found that giraffe body parts had mostly consumptive and trophy uses. One-time suppliers, opportunistic access and widely known markets were the most common means of acquiring giraffe body parts. Results from our models showed that three variables (gender: men, occupation: tourism worker, and land ownership) were correlated significantly and positively with the use of giraffe body parts. We describe the complex links between socio-economic factors and the use of giraffe body parts and highlight the importance of implementing mitigation measures adapted to local contexts to combat a challenge that many species of conservation concern are facing.

The L4n is a nanosecond-kilojoule laser beamline that delivers temporally shapeable nanosecond pulses at a maximum energy of 1.2 kJ. It was recently commissioned at ELI Beamlines and offers unique opportunities for high-pressure, high-energy-density physics, and laser-plasma interaction experiments, particularly due to its high repetition rate of up to 1 shot per minute. Compared to other kJ-class laser systems worldwide, which offer much lower shot rates, the L4n driven experiments will enable significant improvements in collecting data statistics. The results gathered during the first L4n commissioning campaigns, demonstrate the laser capability to deliver hundreds of joules every three minutes with excellent repeatability and clearly show its potential to make significant contributions to the field of high-energy density physics in the coming decades.

Laser Induced Contamination (LIC) is one of the major issues in high energy high repetition rate laser systems. The growth of contamination during the operation of the laser influences the components spectral performance and can lead to the catastrophic damage. Several previous investigations indicate that LIC growth depends on the coatings material and even its deposition method. In our work, we investigate electron-beam deposited HR mirrors for the wavelength of 800 nm. Three different designs were tested in vacuum conditions under high repetition and high energy laser irradiation using femtosecond pulses. Two of the designs are based on quarter wavelength optical thickness (QWOT) layers: last layer of the first mirror is high refractive index film, hafnia in our case, and for the second mirrors the last layer was double QWOT of low refractive index film, silica in our case. For the last coating the E-field was modified by changing the last silica layer thickness. All samples were irradiated below the damage threshold level and LIC observed under confocal microscope. Analysis were obtained by comparing the influence of the last layer and E-field distribution within the multilayer coatings. Conclusions and recommendations for LIC reduction will be presented.

The Mekong River basin (MRB) is a transboundary basin that supports livelihoods of over 70 million inhabitants and diverse terrestrial-aquatic ecosystems. This critical lifeline for people and ecosystems is under transformation due to climatic stressors and human activities (e.g., land use change and dam construction). Thus, there is an urgent need to better understand the changing hydrological and ecological systems in the MRB and develop improved adaptation strategies. This, however, is hampered partly by lack of sufficient, reliable, and accessible observational data across the basin. Here, we fill this long-standing gap for MRB by synthesizing climate, hydrological, ecological, and socioeconomic data from various disparate sources. The data- including groundwater records digitized from the literature-provide crucial insights into surface water systems, groundwater dynamics, land use patterns, and socioeconomic changes. The analyses presented also shed light on uncertainties associated with various datasets and the most appropriate choices. These datasets are expected to advance socio-hydrological research and inform science-based management decisions and policymaking for sustainable food-energy-water, livelihood, and ecological systems in the MRB.

We report on the technological commissioning of the Laser–Plasma Ion Accelerator section of the ELIMAIA user beamline at the ELI Beamlines facility in the Czech Republic. The high-peak, high-average power L3-HAPLS laser system was used with an energy of ~10 J and pulse duration of ~30 fs on target, both in single-pulse and high repetition-rate (~0.5 Hz) mode. The laser pulse was tightly focused to reach ultrahigh intensity on target (~1021 W/cm2) and sustain such laser–plasma interaction regime during high repetition-rate operations. The laser beam, ion beam, and laser–plasma emission were monitored on a shot-to-shot basis, and online data analysis at 0.5 Hz was demonstrated through the full set of used diagnostics (e.g., far and near field, laser temporal diagnostics, X- and gamma-ray detectors, Thomson Parabola ion spectrometer, time-of-flight ion detectors, plasma imaging, etc.). The capability and reliability of the ELIMAIA Ion Accelerator was successfully demonstrated at a repetition rate of 0.5 Hz for several hundreds of consecutive laser shots.

Latest advances of high intensity laser facilities enable the beam transport of petawatt laser pulses and can provide novel fundamental insights in high energy plasma physics or laser fusion. The very high peak intensities put enormous demands on the required large sized optics. Beam transport mirrors reflect pulses with only several tens of fs and maintain their phase while providing best possible laser induced damage threshold. State of the art, such mirrors are mostly manufactured by thermal evaporation techniques as they provide a large and uniform deposition area. Their porous layer structure causes changing spectral characteristics and wavefront when vacuum-air cycled. Especially large sized mirrors can show crazing and thereby decrease up-time of PW beamlines. In contrast, sputtered layers are very compact and provide non changing characteristics. Stable and reproducible sputter processes enable the deposition of more complex design structures necessary for further optimization of the laser induced damage threshold. However, deposition rate is slow and an uniform large sized area difficult to achieve for sputtered coatings. In our study, we show a self-constructed and built-up ion beam sputtering (IBS) machine capable to deposit large sized substrates up to a diameter of 550 mm. A design study is presented to evaluate best HR810nm mirror to meet demanding spectral requirements and providing maximized laser damage threshold for HAPLS at ELI beamlines. In the end, a field optimized design is applied with a measured LIDT of 0.9 J/cm2 at 42 fs and 1 kHz. This design is used to manufacture beam transport mirrors for HAPLS applying IBS.

Coastal zones, which connect terrestrial and aquatic ecosystems, are among the most resource-rich regions globally and home to nearly 40% of the global human population. Because human land-based activities can alter natural processes in ways that affect adjacent aquatic ecosystems, land-sea interactions are increasingly recognized as critical to coastal conservation planning and governance. However, the complex socioeconomic dynamics inherent in coastal and marine socioecological systems (SESs) have received little consideration. Drawing on knowledge generalized from long-term studies in Caribbean Nicaragua, we devised a conceptual framework that clarifies the multiple ways socioeconomically driven behavior can link the land and sea. In addition to other ecosystem effects, the framework illustrates how feedbacks resulting from changes to aquatic resources can influence terrestrial resource management decisions and land uses. We assessed the framework by applying it to empirical studies from a variety of coastal SESs. The results suggest its broad applicability and highlighted the paucity of research that explicitly investigates the effects of human behavior on coastal SES dynamics. We encourage researchers and policy makers to consider direct, indirect, and bidirectional cross-ecosystem links that move beyond traditionally recognized land-to-sea processes.

Animal movement models can be used to understand species behavior and assist with implementation of management activities. We explored behavioral states of an invasive wild pig (Sus scrofa) population that recently colonized central Michigan, USA, 2014-2018. To quantify environmental factors related to wild pig movement ecology and spatio-temporal landscape use, we predicted wild pig behavioral states relative to land cover type, landscape structure (i.e., edge and patch cohesion), and weather conditions. We used global positioning system (GPS)-collars and monitored 8 wild pigs from 2014-2018. We fit local convex hulls and calculated movement metrics revealing 3 wild pig behavioral states (resting, exploratory, and relocating) and constructed a 3-level model to predict behavioral state probabilities relative to biotic and abiotic conditions. Probabilities of exploratory and resting behaviors were higher nearer to riparian and open herbaceous cover types (oftentimes emergent marsh), indicating that these cover types provided security cover during activity and bedding. Hard mast cover types had a strong positive association with relocating behaviors. More cohesive patches of agriculture and shrub cover types were associated with higher probabilities of exploratory behaviors, while resting was more likely in continuous patches of agriculture (mostly mid-summer corn). The probability of exploratory behaviors increased exponentially with warming ambient temperature. Our results may be used by managers to develop control strategies conducive to landscape and environmental conditions where the likelihood of encountering wild pigs is highest or targeting wild pigs when in a behavioral state most vulnerable to a particular removal technique.

Negative interactions between humans and wildlife (i.e. those presenting risks to human security or private property) can trigger retaliation and potential human-wildlife conflict (HWC). The nature and strength of these human responses may depend on previous interactions with wildlife and can be shaped by landscape conditions. However, the ways in which previous experiences and landscape conditions interact to shape peoples' attitudes towards wildlife are not well-understood. We conducted our study in Tsavo Conservation Area, Kenya, which experiences some of the highest rates of HWC documented in East Africa. We explored how previous experiences with wildlife and landscape conditions interact to inform the attitudes of people towards wildlife. We conducted semi-structured surveys among 331 households and fit an ordinal mixed-effects regression model to predict human attitudes to wildlife as a function of landscape conditions and previous interactions. Respondents indicated that baboons, elephants, and lions posed the greatest risks to human security and private property. Households experiencing risks from wildlife wanted wildlife populations to decrease, whereas households depending on grazing lands outside the study area wished to see wildlife increase. Our study demonstrates that human-wildlife interactions have important social and spatial contexts, and are not uniform across households in the same area owing to location of private property. Correspondingly, for interventions to be effective, we recommend considerations of local contexts and landscape conditions of communities.

The latest advances in petawatt laser technology within the ELI Beamlines project have stimulated the development of large surface area dielectrically coated mirrors meeting all demanding requirements for guiding the compressed 30 J, 25 fs HAPLS laser beam at 10 Hz repetition rate and a center wavelength of 810 nm entirely in vacuum. We describe the production and evaluation of Ta2O5/HfO2/SiO2 ion beam sputtered coated (440 × 290 × 75) mm3 beam transport mirrors. No crazing was observed after thirty vacuum-air cycles. A laser induced damage threshold of 0.76 J/cm2 (fluence on mirror surface) was achieved and maintained at high shot rates.

We have developed a new class of meter-sized, multilayer dielectric gratings designed for operating at 1060nm. The design allows for 3.4X more total energy on the grating compared to the present state of the art.

Vacuum chambers are frequently used in high-energy, high-peak-power laser systems to prevent deleterious nonlinear effects, which can result from propagation in air. In the vacuum sections of the Allegra laser system at ELI-Beamlines, we observed degradation of several optical elements due to laser-induced contamination (LIC). This contamination is present on surfaces with laser intensity above 30 G W / c m 2 with wavelengths of 515, 800, and 1030 nm. It can lead to undesired absorption on diffraction gratings, mirrors, and crystals and ultimately to degradation of the laser beam profile. Because the Allegra laser is intended to be a high-uptime source for users, such progressive degradation is unacceptable for operation. Here, we evaluate three methods of removing LIC from optics in vacuum. One of them, the radio-frequency-generated plasma cleaning, appears to be a suitable solution from the perspective of operating a reliable, on-demand source for users.

State wildlife management agencies in the United States have depended on a “user-pay” funding model for conservation efforts that relies on revenue from hunting license sales and a federal excise tax on firearms, ammunition, and archery equipment. Declines in hunting participation, however, jeopardize sustainability of the current funding model. Ensuring support among stakeholders for wildlife management and conservation may require expanding sources of funding and incorporating the perspectives and values of a diversifying constituency into decision making processes. We used a web-based survey of wildlife-associated recreationists in Michigan, USA to evaluate support for a range of conservation funding policies. Respondents self-identified primarily as hunters ( n = 2,558) or wildlife watchers ( n = 942). We used binary logistic regression to evaluate support for four conservation funding policy options: state sales tax, lottery proceeds, extractive industry revenue, and a user-based tax on outdoor gear (i.e., “backpack tax”). Determinants of support varied by type of policy and stakeholder characteristics. We found no statistically significant differences between hunters and wildlife watchers in their support for conservation funding policies when accounting for other variables such as wildlife value orientations, engagement in stewardship behaviors, age, and gender. The industry-based policy achieved the greatest level of approval, while the backpack tax had the lowest. Respondents were mixed in their support of the sales tax and lottery proceeds options. Cluster analysis revealed three homogenous groups related to conservation funding policies: “strong support,” “mixed/opposed,” and “anti-backpack tax.” Clusters differed in their support for conservation funding policies and on psychological and demographic variables. The “strong support” and “anti-backpack tax” groups differed in their levels of stewardship engagement, knowledge of conservation funding mechanisms, and support for the backpack tax option. The “mixed-opposed” group tended to be older, less educated, and less likely to be a member of a conservation organization. Results suggest support for conservation funding differs by policy type and social and psychological characteristics of stakeholders. Based on differences in policy support revealed in this study, we suggest a multi-tiered approach to funding conservation and building on support among wildlife stakeholders to mitigate the looming funding crisis for state wildlife agencies.

ABSTRACT Private‐land, deer‐hunting cooperatives seek to facilitate collective action to restrain buck harvest, encourage doe harvest, and improve hunter satisfaction. We evaluated 15 deer‐hunting cooperatives in southern Michigan to assess whether perceived satisfaction among 348 members was affected by deer harvest outcomes, characteristics of cooperative members, agreement over voluntarily established harvest and population management goals, and members' perceived fit with their cooperative. Our results indicate that cooperative members harvested just over 2 antlerless deer for every antlered buck, compared to an overall hunter harvest ratio of approximately 1:1 across all of southern Michigan. Perceived satisfaction levels generally increased among cooperative members after joining a cooperative. Perceived satisfaction was positively correlated with members' perceived fit within the cooperative, members' perceived agreement with other cooperative members on harvest and management goals, years of membership and antlerless harvest, and negatively associated with member age. Our results suggested that efforts to promote the formation and successful operation of private, deer‐management cooperatives may provide a way for state wildlife agencies to leverage collective action to enhance deer management capacity, boost hunter satisfaction, and potentially increase hunter recruitment, retention, and reactivation. © 2021 The Wildlife Society.