物理
物理
물리
2000年
10期
596-602
,共7页
快点火%预压缩%超强激光等离子体相互作用
快點火%預壓縮%超彊激光等離子體相互作用
쾌점화%예압축%초강격광등리자체상호작용
fast ignition%precompression%ultraintense laser interaction
“快点火”是近年来提出的激光聚变点火的一种新方式.它的特点是靶丸的压缩和点火分开进行:第一步由通常的多束激光对称辐照靶丸获得高密度;而后由单束超强激光(Iλ2≈1018—20Wμm2/cm2)加热芯部实现点火.和传统的“热斑点火”比较,快点火在压缩方面具有很多优越性:大量节省驱动能量,降低了对驱动均匀性的要求,并且可以达到更高的能量增益.但是超强激光点火却涉及一些非常复杂的问题:在预压缩形成的等离子体中打洞(hole boring);在高密度燃料的边沿产生足够数量的高能量电子(MeV),这些电子的传输加热等.文章简短地讨论这些问题,并研究了几十kJ激光能量实现点火的可能性.
“快點火”是近年來提齣的激光聚變點火的一種新方式.它的特點是靶汍的壓縮和點火分開進行:第一步由通常的多束激光對稱輻照靶汍穫得高密度;而後由單束超彊激光(Iλ2≈1018—20Wμm2/cm2)加熱芯部實現點火.和傳統的“熱斑點火”比較,快點火在壓縮方麵具有很多優越性:大量節省驅動能量,降低瞭對驅動均勻性的要求,併且可以達到更高的能量增益.但是超彊激光點火卻涉及一些非常複雜的問題:在預壓縮形成的等離子體中打洞(hole boring);在高密度燃料的邊沿產生足夠數量的高能量電子(MeV),這些電子的傳輸加熱等.文章簡短地討論這些問題,併研究瞭幾十kJ激光能量實現點火的可能性.
“쾌점화”시근년래제출적격광취변점화적일충신방식.타적특점시파환적압축화점화분개진행:제일보유통상적다속격광대칭복조파환획득고밀도;이후유단속초강격광(Iλ2≈1018—20Wμm2/cm2)가열심부실현점화.화전통적“열반점화”비교,쾌점화재압축방면구유흔다우월성:대량절성구동능량,강저료대구동균균성적요구,병차가이체도경고적능량증익.단시초강격광점화각섭급일사비상복잡적문제:재예압축형성적등리자체중타동(hole boring);재고밀도연료적변연산생족구수량적고능량전자(MeV),저사전자적전수가열등.문장간단지토론저사문제,병연구료궤십kJ격광능량실현점화적가능성.
Fast ignition is a recently proposed new scheme for realizing ignition of inertial confinement fusion, in which the compression of an implosive capsule and its ignition proceed separately. First, the fusion pellet is precompressed by multiple beam lasers in the conventional way to a high density, then ignition is realized by a single ultraintense laser beam (of Iλ2≈1018—20 Wμm2/cm2). Fast ignition is superior to traditional `hot spot ignition' in many aspects in the precompression stage; it drastically reduces the energy required for precompression(about ten times), relaxes the requirement of drive uniformity, and is able to reach higher energy gain. However, ignition by ultraintense laser is very complicated. It involves boring a hole in the precompressed plasma, generating intense hot electrons with MeV energy, transporting them in the dense plasma and heating the high-density core to meet ignition conditions. These problems are briefly discussed and the possibility of ignition with laser energy less than 100kJ is explored.