• Fabrication of Laboratory Astrophysics Targets

    At the University of Michigan we have developed the capability to build and characterize targets for laboratory astrophysics experiments. We are among the only university labs to build high-energy-density targets and have carried out numerous successful experimental days at large laser facilities such as Omega and Nike. Students in the lab develop hands-on experience machining and assembling targets to tens of micron precision using motorized mechanical stages and other in-lab tools. The fabrication efforts are led by engineers Donna Marion and Michael Grosskopf, and performed mainly by undergraduates. Typically targets are manufactured for 3 to 4 shot days per year and typically take at least a couple months to build and characterize. Because the target is destroyed in the experiment, extensive measurements must be taken after the final build to ensure quality and to have full knowledge of reference features for data analysis.

  • Computer Simulations of Laser Experiments

    Computer simulations are key in experimental design and understanding the physical dynamics in a system. We run simulations to determine experimental parameters, and to better understand results from experiments. We run computer simulations of our laser experiments using a variety of codes, primarily in 1D and 2D. These simulations model our current experiments, as well as simulate the outcomes of possible future designs. The primary code used in our lab is 1D HYADES, a Lagrangian radiation hydrodynamics code calibrated to data for a variety of our main experimental campaigns. H2D, 2D HYADES, is also used in modeling the early time evolution of some of our experiments, often as a means to provide initial conditions to other codes that do not model the laser deposition phase of the experiment. FLASH has been used to model experiments where the hydrodynamic evolution is not dominated by radiative effects. Our lab also works closely with the CRASH (Center for Radiative Shock Hydrodynamics) group in the AOSS department, doing simulations to aid in the development of a radiation hydrodynamic code.

  • X-Ray Radiography

    Because, in the experiments, the targets are entirely destroyed, we must do extensive metrology of the initial conditions of the target and all reference features that have been built into the targets. Especially in our targets that involve low-density foams, it would be greatly beneficial to add the capability to do pre-experiment radiography on our targets to characterize the uniformity of the foam and identify any structure that may be experimentally relevant. We expect to be able to add this ability by building on to our existing vacuum chamber using our current continuous x-ray source. We have been able to develop some x-ray images, but further work must be done in order to get images that show the necessary level of resolution to provide useful information. Work has also recently been done to test films and get acquainted with development techniques for x-ray films.

  • CsI Coater Project

    One part of characterizing the microchannel plates and photodiodes is testing different material coatings and different thicknesses of these coatings. In order to advance our capabilities with this project, we have begun work building a coating system for microchannel plates. It is being designed to deposit well-characterized layers of cesium iodide (CsI) onto the plates. The deposition process must be done under vacuum and the thickness will be measurable with a quartz crystal microbalance. The project is nearing completion of the build phase and should be able to enter into the testing phase very soon. All current progress, both design and build, has been made by a collaboration of undergraduates within our lab, with general supervision and guidance as needed.

  • Database Design and Inventory Management

    Because of the many different experimental campaigns in the lab, we have a great deal of varying target designs that need a wide variety of parts and materials. In order to keep track of the various vendors, suppliers, and materials used in each of the targets, a central database accessible easily to all in lab is in progress. This can also be a repository for old metrology and fabrication data, as well as any other information from projects within the lab. As new students join the group and current lab members leave, it is important that knowledge is well-documented so that it can be passed on from each generation of students to the next.