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We report on progress implementing and testing cryogenically cooled platforms for Magnetized Liner Inertial Fusion (MagLIF) experiments. Two cryogenically cooled experimental platforms were developed: an integrated platform fielded on the Z pulsed power generator that combines magnetization, laser preheat, and pulsed-power-driven fuel compression and a laser-only platform in a separate chamber that enables measurements of the laser preheat energy using shadowgraphy measurements. The laser-only experiments suggest that ∼89% ± 10% of the incident energy is coupled to the fuel in cooled targets across the energy range tested, significantly higher than previous warm experiments that achieved at most 67% coupling and in line with simulation predictions. The laser preheat configuration was applied to a cryogenically cooled integrated experiment that used a novel cryostat configuration that cooled the MagLIF liner from both ends. The integrated experiment, z3576, coupled 2.32 ± 0.25 kJ preheat energy to the fuel, the highest to-date, demonstrated excellent temperature control and nominal current delivery, and produced one of the highest pressure stagnations as determined by a Bayesian analysis of the data.

The performance of Magnetized Liner Inertial Fusion (MagLIF) experiments is sensitive to the amount of laser energy coupled to the fuel during the preheat stage. 1 A significant source of energy loss in this process comes from the need to heat a laser entrance hole foil (LEH) located at the entrance to the target that is required to contain the gaseous fusion fuel. The energy lost to the LEH is a function of its thickness which can be reduced by cryogenically cooling the fuel, lowering the pressure required for a given fuel density. 2 To realize this, a cryogenically-cooled laser target platform was commissioned in the Pecos chamber that enables rapid testing of preheat configurations, 3 and a cryogenically-cooled MagLIF configuration was tested that symmetrically cools the liner from the top and bottom, minimizing temperature gradients across the target. These new capabilities were utilized to perform a cryogenically-cooled MagLIF experiment that demonstrated >2 kJ of preheat energy coupled to the fuel for the first time on Z.

Z-beamlet experiments conducted at the PECOS test facility at Sandia National Laboratories (SNL) investigated the nonlinear processes in laser plasma interaction (or laser-plasma instabilities) that complicate the deposition of laser energy by enhanced absorption, backscatter, filamentation, and beam-spray that can occur in large-scale laser-heated gas cell targets. These targets and experiments were designed to provide better insight into the physics of the laser preheat stage of the Magnetized Liner Inertial Fusion scheme being tested on the SNL Z-machine. The experiments aim to understand the trade-offs between laser spot size, laser pulse shape, laser entrance hole window thickness, and fuel density for laser preheat. Gas cell target design evolution and fabrication adaptations to accommodate the evolving experiment and scientific requirements are described in this paper.

A class of dynamic material property (DMP) experiments on the Sandia National Laboratories pulse power Z-Machine requires planar samples to be held in a panel assembly. A custom press device to fabricate the assemblies has the ability to assemble one sample, window, or stack at a time, resulting in a 1-week lead time for a typical three-pocket panel assembly. Fabrication of targets with more than three pockets can take longer. In late 2015, General Atomics conceptualized a new multi-press device to enable several samples, windows, or stacks to be assembled simultaneously, and a prototype was designed, procured, and outfitted in 6 months. Since June 2016, this multi-press design has successfully assembled 60 planar DMP targets. The development considerations for this new device and the resulting benefits for the fabrication of targets are discussed.

Laser indirect drive is hindered, in part, by two problems: “wall motion” resulting from ablation of the hohlraum inner wall and “preheat” of the fuel capsule. To mitigate wall motion and preheat, a mid-Z–coated high internal phase emulsion, poly(HIPE) foam liner (5.7-mm diameter, 150 μm thick, 2.8 mm long, 33 mg/cm3) was developed and integrated into the hohlraum interior. A zinc oxide coating was applied throughout the poly(HIPE) foam using atomic layer deposition to achieve 149 ± 14 mg/cm3 bulk density. Preliminary data collected from actual shots at the National Ignition Facility suggest the inclusion of the poly(HIPE) liner reduced preheat threefold and stimulated Brillouin scattering (SBS) fivefold relative to an existing reference shot on a gold hohlraum (wavelength shift also contributed to SBS reduction).

A measurement instrument utilizing dual, chromatic, confocal, distance sensors has been jointly developed by General Atomics and Sandia National Laboratories (SNL) for thickness and flatness measur...

In this paper, we describe the reasoning that leads us to focus on the so-called curing process where a solid poly(ɑ-methylstyrene) (PAMS) shell is formed from the initial solution phase. We demons...

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary plasma physics, and developing integrated scenarios for achieving high performance fusion regimes. Fundamental investigations into fusion energy science find that anomalous dissipation of runaway electrons (RE) that arise following a disruption is likely due to interactions with RE-driven kinetic instabilities, some of which have been directly observed, opening a new avenue for RE energy dissipation using naturally excited waves. Dimensionless parameter scaling of intrinsic rotation and gyrokinetic simulations give a predicted ITER rotation profile with significant turbulence stabilization. Coherence imaging spectroscopy confirms near sonic flow throughout the divertor towards the target, which may account for the convection-dominated parallel heat flux. Core-boundary integration studies show that the small angle slot divertor achieves detachment at lower density and extends plasma cooling across the divertor target plate, which is essential for controlling heat flux and erosion. The Super H-mode regime has been extended to high plasma current (2.0 MA) and density to achieve very high pedestal pressures (~30 kPa) and stored energy (3.2 MJ) with H 98y2 ≈ 1.6–2.4. In scenario work, the ITER baseline Q = 10 scenario with zero injected torque is found to have a fusion gain metric independent of current between q 95 = 2.8–3.7, and a lower limit of pedestal rotation for RMP ELM suppression has been found. In the wide pedestal QH-mode regime that exhibits improved performance and no ELMs, the start-up counter torque has been eliminated so that the entire discharge uses ≈0 injected torque and the operating space is more ITER-relevant. Finally, the high- (⩽3.8) hybrid scenario has been extended to the high-density levels necessary for radiating divertor operation, achieving ~40% divertor heat flux reduction using either argon or neon with P tot up to 15 MW.

A multi-frame shadowgraphy diagnostic has been developed and applied to laser preheat experiments relevant to the Magnetized Liner Inertial Fusion (MagLIF) concept. The diagnostic views the plasma created by laser preheat in MagLIF-relevant gas cells immediately after the laser deposits energy as well as the resulting blast wave evolution later in time. The expansion of the blast wave is modeled with 1D radiation-hydrodynamic simulations that relate the boundary of the blast wave at a given time to the energy deposited into the fuel. This technique is applied to four different preheat protocols that have been used in integrated MagLIF experiments to infer the amount of energy deposited by the laser into the fuel. The results of the integrated MagLIF experiments are compared with those of two-dimensional LASNEX simulations. The best performing shots returned neutron yields ∼40–55% of the simulated predictions for three different preheat protocols.

Deuterated polyethylene films as thin as 50 μm have been produced using a four-post heated press method. These films are then cut into the desired shape (foil) and are used for the magnetic recoil ...

We report on a high convergence ratio liquid layer capsule implosion performed on the National Ignition Facility and contrast it to two previously reported layered implosions, in order to better understand how the capsule design impacts the hydrodynamic stability properties of implosions. Three implosions were performed with similar convergence ratios, fuel entropy, in-flight aspect ratios, and unablated shell mass; these qualities are important for determining hydrodynamic stability. Nevertheless, while two of these implosions exhibited robustness to asymmetries, including our recent experiment that had abnormally large amplitude long-wavelength capsule asymmetries, and produced more than 80% or the yield predicted by one-dimensional (1D) simulations, which do not account for the impacts of hydrodynamic instabilities, the third implosion produced only 14% of the yield from a 1D simulation. We perform a detailed computational analysis of these three shots, which suggests that the combination of several large asymmetry seeds result in the significantly degraded performance: a large 30 μm fill tube, the presence of a microstructure in the high density carbon ablator, and a higher level of drive asymmetry. This indicates that while it is possible to stabilize a high convergence ratio implosion through various means, the factors that determine stability cannot be considered independently. Furthermore, when these asymmetries are combined in 2D simulations, they can exhibit destructive interference and underpredict the yield degradation compared to experiment and three-dimensional simulations.

Possible designs for future direct- and indirect-drive targets required for the National Ignition Facility (NIF) include resorcinol formaldehyde (R/F) foam shells. Depending on the experiment type, the shell dimensional specifications can range from 1.5- to 3.5-mm diameter with a 100- to 200-μm wall. This paper will discuss the adjustments and modifications of the process developed for smaller-diameter (˜900-μm) OMEGA-scale R/F shells that were used to fabricate these higher-aspect-ratio NIF-scale shells.

A series of Magnetized Liner Inertial Fusion (MagLIF) experiments have been conducted in order to investigate the mix introduced from various target surfaces during the laser preheat stage. The material mixing was measured spectroscopically for a variety of preheat protocols by employing mid-atomic number surface coatings applied to different regions of the MagLIF target. The data show that the material from the top cushion region of the target can be mixed into the fuel during preheat. For some preheat protocols, our experiments show that the laser-entrance-hole (LEH) foil used to contain the fuel can be transported into the fuel a significant fraction of the stagnation length and degrade the target performance. Preheat protocols using pulse shapes of a few-ns duration result in the observable LEH foil mix both with and without phase-plate beam smoothing. In order to reduce this material mixing, a new capability was developed to allow for a low energy (∼20 J) laser pre-pulse to be delivered early in time (−20 ns) before the main laser pulse (∼1.5 kJ). In experiments, this preheat protocol showed no indications of the LEH foil mix. The experimental results are broadly in agreement with pre-shot two-dimensional HYDRA simulations that helped motivate the development of the early pre-pulse capability.

Single and double sapphire spheres have been precisely suspended in 300 mg/cm 3 RF aerogels without a supporting stalk by modifying parameters such as gelation time and stability of the aerogel precursor solution and use of a vacuum holder for the sphere placement. A process for fabricating a single-sphere target was also developed using a spider silk support (approximately) 100 times thinner than the earlier work on similar targets. Characterization of the ball placement and the aerogel was done by radiography. Data from the characterization of these targets showed that the ball was accurately placed and the aerogel matrix was not significantly altered.

A new technique has been developed for attaching glass and polyimide tubes to National Ignition Facility and OMEGA-scale capsules. Resorcinol-formaldehyde foam and CD fill tube assemblies are designed for OMEGA laser capabilities by the University of Rochester Laboratory for Laser Energetics. Because of the porous structure of the foam, test procedures have been implemented to guarantee the target assemblies are leaktight under room and cryogenic temperatures. Based on the type and conditions of the target, ultraviolet glue or two-part epoxy glue is applied to particular sections on the assembly. Development has been conducted to overcome issues dealing with the adhesives, test procedures, and fill tube designs described in this paper.

The baseline design for the laser-driven Inertial Fusion Energy (IFE) target is a 4.6 mm foam capsule with a polymer overcoat of 1 to 5 microns. The specifications for this overcoat include surface finish, permeation properties, uniform wall thickness and conformal coating of the foam shell. Many of these specifications are not unlike the full density polymer National Ignition Facility targets, but the foam shell adds to the fabrication difficulty. Since the foam surface is composed of open cells, creating the overcoat by typical vacuum deposition processes would start by replicating the foam surface making it very difficult to achieve the required surface specification. Instead an overcoat is made using interfacial polymerization at the edge of the foam surface. This is done by filling the foam shell with an organic solvent containing one reactant, then placing the shell into water containing another reactant. The reaction occurs only at the interface of the two solutions. This technique was pioneered at the Institute of Laser Engineering (Osaka University) with 0.8 mm diameter methacrylate shells.1 The process was later extended to 0.9 mm diameter resorcinol-formaldehyde and divinyl benzene (DVB) shells. 2,3 For the High Average Power Laser Program target we need to extend the process to 4.6 mm diameter DVB foam shells. The properties of the DVB foam and the larger diameter of the shell make it more difficult to produce a gas tight shell. This report will explain how we are adapting the process and the results to date.

Previously we have developed a production process for both standard density (100 mg/cc) and high-density (180-200 mg/cc) resorcinol formaldehyde (RF) foam shells with a triple orifice droplet generator. These foam shells are needed for direct drive inertial confinement laser fusion experiments on the OMEGA laser facility at the University of Rochester. Although this process has been developed into production mode, the yield of high density RF (HDRF) and standard density (SDRF) shells with acceptable wall uniformity has been poor. This yield depends on the type of RF shell that is being fabricated. For HDRF this yield is ~5% while for the SDRF shells the yield is ~30%. We have made improvements in the yield of these shells that meet the wall uniformity specification by modifying the composition of the outer oil solution (O2) in the microencapsulation emulsion. This improvement was achieved by a small addition (0.60 wt.%) of a styrene-butadiene-styrene (SBS) block copolymer into the outer oil (O2) s...

We report on the progress made to date for a Laboratory Directed Research and Development (LDRD) project aimed at diagnosing magnetic flux compression on the Z pulsed-power accelerator (0-20 MA in 100 ns). Each experiment consisted of an initially solid Be or Al liner (cylindrical tube), which was imploded using the Z accelerator's drive current (0-20 MA in 100 ns). The imploding liner compresses a 10-T axial seed field, B z ( 0 ) , supplied by an independently driven Helmholtz coil pair. Assuming perfect flux conservation, the axial field amplification should be well described by B z ( t ) = B z ( 0 ) x [ R ( 0 ) / R ( t )] 2 , where R is the liner's inner surface radius. With perfect flux conservation, B z ( t ) and dB z / dt values exceeding 10 4 T and 10 12 T/s, respectively, are expected. These large values, the diminishing liner volume, and the harsh environment on Z, make it particularly challenging to measure these fields. We report on our latest efforts to do so using three primary techniques: (1) micro B-dot probes to measure the fringe fields associated with fluxmore » compression, (2) streaked visible Zeeman absorption spectroscopy, and (3) fiber-based Faraday rotation. We also mention two new techniques that make use of the neutron diagnostics suite on Z. These techniques were not developed under this LDRD, but they could influence how we prioritize our efforts to diagnose magnetic flux compression on Z in the future. The first technique is based on the yield ratio of secondary DT to primary DD reactions. The second technique makes use of the secondary DT neutron time-of-flight energy spectra. Both of these techniques have been used successfully to infer the degree of magnetization at stagnation in fully integrated Magnetized Liner Inertial Fusion (MagLIF) experiments on Z [P. F. Schmit et al. , Phys. Rev. Lett. 113 , 155004 (2014); P. F. Knapp et al. , Phys. Plasmas, 22 , 056312 (2015)]. Finally, we present some recent developments for designing and fabricating novel micro B-dot probes to measure B z ( t ) inside of an imploding liner. In one approach, the micro B-dot loops were fabricated on a printed circuit board (PCB). The PCB was then soldered to off-the-shelf 0.020- inch-diameter semi-rigid coaxial cables, which were terminated with standard SMA connectors. These probes were recently tested using the COBRA pulsed power generator (0-1 MA in 100 ns) at Cornell University. In another approach, we are planning to use new multi-material 3D printing capabilities to fabricate novel micro B-dot packages. In the near future, we plan to 3D print these probes and then test them on the COBRA generator. With successful operation demonstrated at 1-MA, we will then make plans to use these probes on a 20-MA Z experiment.« less

Poly(a-methylstyrene) (PAMS) shells are made by microencapsulation and used in the fabrication of a large variety of targets for the inertial confinement fusion (ICF) program. Although this process has previously been developed into production mode, the yield of shells with acceptable sphericity and wall uniformity in the OMEGA size range (800-1000 μm) has been poor (∼ 18%). We have made improvements in the yield of these shells by modifying the composition of the outer water solution (W2) in the microencapsulation emulsion. This improvement was achieved by increasing the concentration of Poly Vinyl Alcohol (PVA) from 0.3% to 1.0% and an addition of 0.1% Poly Acrylic Acid (PAA). These modifications were aimed at increasing the interfacial surface tension in the emulsion but also appear to have played a role in density matching the components in the PAMS emulsion. These modifications improved the out of round (OOR) and non-concentricity (NC) of the PAMS mandrels resulting in as increase in the yield of target quality batches based on these basic criteria from 18% to over 80%. Meanwhile, the vacuole content and the surface finish of the PAMS shells were not adversely affected by these changes.

A variety of silica, metal oxide, and metal doped aerogels are being developed for use as laser target materials. Silica aerogels have been produced with controlled densities as low as 5 mg/cc, and have been produced as bulk molds. Recently, 100 mg/cc small beads and hollow shells have also been fabricated using microencapsulation techniques. Metal oxide aerogels such as tantalum oxide (Ta 2 O 5 ) and tin oxide (SnO 2 ) are two other low-density materials that have been fabricated. Aerogels with embedded metal particles are also of interest and several methods for producing these composite aerogels are being explored. Each method limits excessive aggregation of the metal so that the end product has a uniform loading of small metal particles. Ion implantation is being investigated as another method that allows more control of the metal doping. With ion implantation the metal dopant can be placed in a narrow distribution beneath the surface of an aerogel, and initial results of 1 MeV Au - implanted in 67 mg/cc SiO 2 are described.

Resorcinol Formaldehyde (R/F) foam has been used in the fabrication of direct drive shell targets for Inertial Fusion Confinement (ICF) experiments at the University of Rochester's Laboratory for Laser Energetics (LLE). Recent cryogenic experiments at LLE using R/F shells have shown the necessity of larger pore foam compared to the standard R/F formulation. In this paper, we report controlling the pore size of R/F foam with concomitant control of the gelation time, which is crucial for successful shell fabrication. The "standard" formulation, with pores of 0.5 μm) through reaction limited aggregation. However, this formulation decreased the gelation time, which decreased the yield of shells with proper wall uniformity (∼ 30%) to an unacceptable level of

We are performing research and development to increase production quantity and yield for Inertial Fusion Energy targets for laser fusion. A key component of the laser fusion target is an approximat...

OAK-B135 New high gain designs for direct drive ignition on NIF require foam shells. Scaled down versions of these designs are needed for near term experiments on the OMEGA laser facility at the Laboratory Laser Energetics (LLE). These shells need to be about 1 mm in diameter and 50-100 {micro}m wall thickness and densities of 100-250 mg/cc. In addition, a full density permeation seal needs to be deposited for retention of the fill gas at room temperature or the ice at cryogenic temperatures. They have fabricated such shells using Resorcinol-formaldehyde (R/F) as the selected foam material due to its transparency in the optical region. Extensive characterization of the wall uniformity of these shells has been performed. The foam shells have {approx} 5%-6% non-concentricities on the average. A full density permeation seal has been deposited on the R/F shells using two different techniques. In the first technique R/F shells are coated directly with plasma polymer to thicknesses of 3-4 {micro}m. In the second technique, R/F shells are coated with polyvinylphenol, using a chemical interfacial polymerization technique. Data on surface finish and gas retention for R/F shells coated by both methods are provided.

All planned National Ignition Facility (NIF) capsule targets except machined beryllium require a glow discharge polymer (GDP) mandrel upon which the ablator is applied. This mandrel, {approx}2 mm in diameter, must at least meet if not exceed the symmetry and surface finish requirements of the final capsule. Such mandrels are currently produced by the three-step depolymerizable mandrel technique. The quality of the final mandrel depends upon precise optimization and execution of each of the three steps. We had shown previously that fabrication of a mandrel which met the symmetry and surface finish requirements was feasible using this technique. In this paper we will discuss recent progress towards converting this process into a high yield, production scale process.

Traditionally, the synthesis of resorcinol formaldehyde (R/F) aerogels consists of a 2-step (base/acid catalysis) polycondensation reaction. Since the acid catalyst in the reaction controls the gelation time, the replacement of the acid catalyst with a non-ionic photo-acid generator decreased the gelation time from hours, down to a few minutes at room temperature using a UV light source. The reaction rate was not only fast, but the liquid precursor was stable for several hours prior to UV exposure. After drying, the resulting aerogel porosity was characterized by scanning electron microscopy (SEM) and confirmed the internal structure of the aerogel was similar to the original R/F pore structures. This paper will discuss the modifications made to the traditional R/F formulation, as well as the benefits of a fast gelation time for aerogel casting applications such as thin films, cylinders, and solid and hollow microspheres.

Resorcinol formaldehyde (R/F) aerogels have been used in a variety of laser targets for Inertial Confinement Fusion (ICF) experiments in the form of thin films, cast shapes such as cylinders and cubes, and hollow and solid microspheres. Besides ICF experiments, R/F aerogel can be used for capacitors, batteries, thermal insulation, absorption/filtration media, and chromatographic packing applications. Traditionally, R/F aerogel is synthesized using a 2-step (base/acid catalysis) polycondensation reaction. We have developed a novel process to synthesize the R/F aerogel using free radical UV initiator at room temperature in 10 minutes using a UV light source. This paper will review this process, which was developed to synthesize R/F aerogels using UV-free radical initiators. Scanning electron microscopy results will also be discussed to show that the aerogel pore structure is similar to traditional R/F aerogels. Fabrication of solid and hollow microspheres for ICF experiments using this R/F aerogel synthesis technique and the technique’s limitations will also be discussed.

This work investigates an alternative way to modify the pore size of a 100 mg/cc resorcinol formaldehyde (R/F) aerogel without any significant change to the aerogel target density. This was successfully accomplished by an addition of hydrophilic polymer additive [Poly Vinyl Alcohol (PVA) or Poly Acrylic Acid (PAA)] to the R/F precursor solution which acts as an impurity in the reaction. The polymer can modify the cross linking or aggregation of the primary particles which can change the structure formation of the aerogel, thus changing the pore size. This paper will discuss this process modification and the fabrication of hollow, large pore R/F aerogel spheres that are used for direct drive inertial confinement fusion (ICF) cryogenic ice layering experiments at the University of Rochester Laboratory for Laser Energetics (LLE). The aerogels were characterized using scanning electron microscopy (SEM), nitrogen gas adsorption, and ultra small angle x-ray scattering (USAXS).

Low density Sn doped resorcinol formaldehyde aerogels were fabricated for extreme ultraviolet (EUV) source emission lithography experiments (EUVL). EUVL is a candidate to succeed conventional optical lithography. EUVL requires a reliable emission (13.5 nm) source. One type of source is a laser-produced plasma. Several laser-plasma source materials have been considered such as lithium, xenon and tin. Tin is considered ideal because it has a high conversion effeciency. However, solid tin targets create a large quantity of debris which can damage the optics of the laser system. As a solution to this problem, we minimized the amount of tin by dispersing it in a low density resorcinol formaldehyde (R/F) matrix. These targets were fabricated into small spheres using the microencapsulation method. Initial experimental results show that these targets yield a similar intensity in the EUV regime when compred to a full density Sn target.

This paper reviews the processes developed at General Atomics (GA) in the past several years to fabricate a variety of spherical foam targets at various densities for the inertial confinement fusion (ICF) community. The two most common chemical systems used to produce spherical foam targets have been resorcinol-formaldehyde (R/F) aerogel and divinylbenzene (DVB). Spherical targets have been made in the form of shells and beads with diameters ranging from approximately 0.5 to 4.0 mm, and densities from 100 mg/cc to 250 mg/cc, with typical high yield of intact shells or beads of 90%-95%. Permeation barriers have been developed and deposited on both R/F and DVB shells. We have also made R/F foam shells with higher pore size (0.10-0.50 mum) in order to increase the cryo-fill fraction when these shells are cryogenically layered with D2. Another spherical target that is currently under development that will also be discussed is silica aerogels shells and beads. Other foam target materials currently under development, such metal doped R/F aerogel beads for extreme ultra violet (EUV) source experiments will also be discussed

Hollow foam spheres are needed for laser fusion experiments on the OMEGA laser facility at the University of Rochester as part of the demonstration of the feasibility of inertial confinement fusion. Previously polymer based foam and aerogel shells have been produced using resorcinol-formaldehyde (R/F) and divinylbenzene (DVB). In this paper we discuss the development of silica aerogel (SAG) shells. SAG may have the increased robustness, which is important in processing these laser targets. SAG shells were fabricated by the microencapsulation method using a triple orifice droplet generator. This technique allows for precise control of the shell diameter and wall thickness. Reduction of the aerogel gelation time is crucial to fabrication of intact shells with high yield. In addition, the proper choice of the components of the different phases of the microencapsulation process is essential for fabrication of intact SAG shells with proper sphericity and wall uniformity. The density of shells fabricated is approximately 100 mg/cc and the diameter ranges from 700–2000 μm, with a wall thickness of 50–200 μm. Development of a full density permeation barrier for retention of the fusion fuel will also be discussed.

As is true for current-day commercial power plants, a reliable and economic fuel supply is essential for the viability of future Inertial Fusion Energy (IFE) [Energy From Inertial Fusion, edited by W. J. Hogan (International Atomic Energy Agency, Vienna, 1995)] power plants. While IFE power plants will utilize deuterium-tritium (DT) bred in-house as the fusion fuel, the “target” is the vehicle by which the fuel is delivered to the reaction chamber. Thus the cost of the target becomes a critical issue in regard to fuel cost. Typically six targets per second, or about 500 000∕day are required for a nominal 1000MW(e) power plant. The electricity value within a typical target is about $3, allocating 10% for fuel cost gives only 30 cents per target as-delivered to the chamber center. Complicating this economic goal, the target supply has many significant technical challenges—fabricating the precision fuel-containing capsule, filling it with DT, cooling it to cryogenic temperatures, layering the DT into a uniform layer, characterizing the finished product, accelerating it to high velocity for injection into the chamber, and tracking the target to steer the driver beams to meet it with micron-precision at the chamber center.