单粒子效应研究中提高LET值的特殊方法

Special Way of Increasing Linear Energy Transfer Value Used for Study on Single Event Effect

为满足单粒子效应研究对更大的线性能量转移 (LET)值 ( 80MeV·mg- 1 ·cm- 2 以上 )的要求 ,在HI 1 3串列加速器上发展了用于高剥离态离子的加速、引出及 0°束Q3D磁谱仪焦面辐照技术。当用高剥离态 (Q1 =1 5 ,Q2 =2 5 )重离子1 2 7I 45°倾斜入射时 ,已得到的LET值为 86 7MeV·mg- 1 ·cm- 2 ,Si中射程约 2 0 μm。使用谱仪的散焦特性 ,辐照束的强度、均匀性和束斑大小可在大范围内调整 ,注量率为几十至 5× 1 0 5s- 1 ·cm- 2 ,均匀性好于 90 % ,束斑为1 0mm到5 0mm ,其纯度好于 98%。

A special technique used for the acceleration and extraction of heavy ions with highly stripped charge state as well as for device irradiation with 0° ion beam and at the focal plane of Q3D magnetic spectrometer was developed in order to meet the demand of even higher linear energy transfer(LET) values (above 80 MeV &middot mg-1 &middot cm-2) of the heavy ions in the single event effect studies of satellite devices with HI-13 tandem accelerator. By use of the heavy ion 127I with high change state (Q1 = 15, Q2 = 25) the obtained LET value is 86.7 MeV &middot mg-1 &middot cm-2 for 45° incidence of beam to the devices and with the reign of 20 μm in Si. Based on the utilizing of the characteristics of defocusing of the spectrometer, the irradiation beam intensity, uniformity, and beam spot size can be adjusted in a wide range, the intensities are few to 5 × 105 s-1 &middot cm-2, the uniformity is better than 90%, the spot size are φ10 mm to φ50 mm and the purity is better than 98%.