改善芯部加料效率的新机制研究  

Isotope corrections of ablation rates in fusion plasma for different solid hydrogen molecule pellets

作　　者：邓柏权[1] 彭利林[1] 严建成[1] 王晓宇[1] 

机构地区：[1]核工业西南物理研究院,成都610041

出　　处：《核聚变与等离子体物理》2005年第1期49-54,共6页Nuclear Fusion and Plasma Physics

基　　金：国家自然科学基金资助项目(19889502;10085001)

摘　　要：对五种不同组合的固态氢同位素靶丸H2、HD、D2、DT和T2在聚变等离子体中的消融率作了同位素修正。结果表明,由于这种新机制———同位素效应,引起的靶丸半径烧蚀率修正从氢靶丸的1下降到氚靶丸的0.487。因而在消融率计算时是不可忽略的,这些修正可导致更深的靶丸消融物质沉积因而改善芯部加料效率。更重要的是,考虑到同位素效应后,对ITER的加料困难有适度的减轻。进一步的数值计算工作表明,以低场侧注入半径rp0=0.5cm的DT靶丸,同样渗入ITER等离子体100cm,按Kuteev的2D透镜模型,同位素修正使要求靶丸的初速度从vp0=24.27×105cm·s-1减小到16.2×105cm·s-1,而对Parks模型,从vp0=8.07×105cm·s-1减小到5.4×105cm·s-1。如果从中平面高场侧注入尺寸rp0=0.5cm的DT靶丸,当合并考虑同位素修正和由于消融云内外比压差产生的净垂直极化电流引起的沿大半径方向漂移后,vp0可降低到工程技术上比较容易实现的低速1.73×104cm·s-1从而可能使靶丸的消融物质沉积到ITER等离子体中心。The isotope corrections of ablation rates in fusion plasma for five combinations of solid isotopic hydrogenic pellets, H2, HD, D2, DT, T2 have been studied. The results show that modifications caused by the isotope effect for pellet erosion speeds range form 1 for hydrogen pellet down to 0.487 for tritium pellet and are not negligible in ablation rate calculations. These effects lead to deeper pellet substance deposition and improve the core fueling efficiency. The ITER core fueling difficulty will be moderately alleviated by taking into account of the isotope effects. For instance, our other numerical calculation results show that, with DT pellet of radius rp0 = 0.5 cm injected from lower field side to get the penetration length L - 200 cm in the ITER plasma, the required pellet speed will be reduced to 16.2 km·s-1 from 24.27 km·s-1 based on Kuteev 2D lentil model, and to 5.4 km·s-1 from 8.07 km·s-1 based on the Parks model. Our other work also shows if a DT pellet with size rp0 = 0.5 cm is injected from mid-plane high field side of ITER, the ablated substance of pellet can be deposited to the core plasma even if the velocity is as low as 173 m·s-1 by considering the isotope effects and the drift in major radius direction caused by the vertical polarization current due to the difference of specific pressures between the inner and outer cloudlet.

关 键 词：靶丸 ITER 固态氢 等离子体 同位素效应 聚变 消融 可导 半径 修正 

分 类 号：O571.43[理学—粒子物理与原子核物理] TL632[理学—物理]