HiPER laser reference design

Hydrogen accumulation in nanostructured as compared to the coarse-grained tungsten

“…In this fusion approach, the energy of the light species impinging into the PFM strongly depends on the target illumination mode: direct or indirect. In reactors like HiPER, [24][25][26], operating with direct drive targets, ions are expected to reach PFM with energies well above the displacement threshold. Thus, the radiation-induced damage configuration, in laser fusion reactors with direct targets will be quite different from that expected in MC reactors.…”

Challenges of high power diode-pumped lasers for fusion energy

“…The last critical parameter for DPSSLs is the cost of laser diodes because only quasi-continuous mode operation (QCW) at low duty cycle (1%) is possible for this type of medium repetition rate (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). This excludes the possibility of using CW diodes for which the market is larger.…”

“…On scaling the size of the gain medium, a high gain diode-pumped solid-state amplifier will quickly suffer from amplified spontaneous emission leading to a reasonable transverse size that cannot exceed 12–15 cm [8, 20] . This unit part or unit cell is called a single beam line (or beamlet) and one laser beam is a ‘bundle’ of ‘’ single beam lines.…”

Repetition rate target and fusion chamber systems for HiPER

“…In the given ignition scenario, each beam will deliver of approximately 10 kJ of energy at the second or third harmonics. This beam can be provided as a bundle of smaller-aperture beams [2], and this solution can be conveniently used for shaping both temporal and spatial profile of the focus. Table 2.…”

“…The designed focusing scheme employs a 2f-2f arrangement [2] using the final lens with f =4 m, located at 8 m from the chamber center. The concrete pinhole placed in the surrogate focus in the object plane of this lens provides shielding of the upstream final optics elements from the fusion products.…”