title: Petawatt-laser direct heating of uniformly imploded deuterated-polystyrene shell target.
abstract: A uniformly imploded deuterated polystyrene (CD) shell target is fast-heated by a Petawatt (PW) laser without cone guide. The best illumination timing is found to be in a narrow region around 80+/-20 picoseconds from the onset of the stagnation phase, where thermal neutrons are enhanced four to five times by the PW laser of energy less than 10% of the implosion laser. The timing agrees with the timings of enhancement of the x-ray emission from the core and reduction of the bremsstrahlung radiation from scattered hot electrons. The PW laser, focused to the critical density point, generates the energetic electrons within as narrow an angle as 30 degrees , which then heats the imploded CD shell to enhance thermal neutrons. These results first demonstrate that the PW laser directly heats the imploded core without any conelike laser guide.
authors.affiliation: Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871, Japan. yoneyosi@ile.osaka-u.ac.jp
authors.forename: Yoneyoshi
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Sentoku
authors.forename: Shin
authors.initials: S
authors.lastname: Akamatsu
authors.forename: Wataru
authors.initials: W
authors.lastname: Sakamoto
authors.forename: Kazuo A
authors.initials: KA
authors.lastname: Tanaka
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kodama
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nishimura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inubushi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Nakai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Watari
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Norimatsu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sunahara