Near threshold electron damage in aluminium: Purity effects
Near threshold electron damage in aluminium: Purity effects
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铝中的近阈值电子损伤：纯度效应
DOI：
10.1080/00337577408241463
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发表时间：
1974
影响因子：
1
通讯作者：
A. Wolfenden
中科院分区：
文献类型：
--
作者：
A. Wolfenden
在最近的实验中，在电子显微镜中，在150至200 kV的电压范围内，用电子轰击区域精炼铝箔，无论是否预注入氦气。在150 kV下照射约90 min后，在掺氦铝中产生电子损伤。在150 kV下，未注入的铝在4小时以上的辐照时间内没有观察到损伤。由于对铝的意见一致认为原子位移的阈值能量Td接近16 eV（~ 170 keV入射电子束能量），因此在150 kV（rd-14 eV）下观察到的电子损伤构成了“亚阈值”事件的证据。我们已经扩大了我们的显微镜实验，以涵盖在150至200千伏的电压范围内的电子辐照较不纯的铝。证据是在1.50 kV的99.996重量%的纯铝预注入几ppm的氦亚阈值损伤。将Alcoa轧制成0.013 cm厚，切成3.8 × 0.63 cm的带材，在200 ℃下退火30 min。在回旋加速器中将α粒子注入到一些条带中，达到约10 at。ppm氦（计算值），分布均匀，如别处所述。在Hitachi 200 E电子显微镜中，在150、175或200 kV下对6片未注入和注入的铝进行检查和电子辐照。显微镜的其他细节和它的操作已经给出了。轰击时间长达约2小时
In recent experiments’ foils of zone-refined aluminum, both with and without preinjected helium, were bombarded with electrons in the electron microscope operating at voltages in the range 150 to 200 kV. Electron damage was produced in the helium-doped aluminum after about 90 min irradiation time at 150 kV. No damage was seen at 150 kV in the uninjected aluminum for irradiation times over 4 hr. Since the concensus of opinion2-’for aluminum is that the threshold energy for atomic displacement, Td, is near 16 eV (-170 keV incident electron beam energy), the observation of electron damage at 150 kV (rd-14 ev) constituted evidence for “sub-threshold” events. We have extended our microscope experiments to cover electron irradiation of less pure aluminum at voltages in the range 150 to 200 kV. Evidence is presented for sub-threshold damage at 1.50 kV in 99.996 wt% pure aluminum preinjected with a few ppm helium. The results are compared with those for high-purity aluminum.Alcoa was rolled to 0.013 cm thickness, cut into strips measuring 3.8 x 0.63 cm and annealed for 30 min at 200 C. Some of the strips were injected with alpha particles in a cyclotron to about 10 at. ppm helium (calculated value) with a uniforfi distribution, as described elsewhere. 6 Pieces of both uninjected and injected aluminum were examined and electron irradiated in a Hitachi 200E electron microscope operating at 150, 175, or 200 kV. Other details of the microscope and its operation have been given already.’Bombardment times up to about 2 hr