Azevedo G M, Grande P L, Behar M, Dias J F, Schiwietz G
Instituto de Física da Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves 9500, 91501-970, Porto Alegre, RS, Brazil.
Phys Rev Lett. 2001 Feb 19;86(8):1482-5. doi: 10.1103/PhysRevLett.86.1482.
Measurements of the electronic energy loss are presented for (4)He and (7)Li ions channeling along the Si main axial directions at intermediate to high projectile energies. The Barkas effect, an energy-loss enhancement proportional to the third power of the projectile charge at high energies, is clearly separated from other processes. It reaches about 50% for Li ions channeling along the Si [110] direction. The observed Barkas contribution from the valence-electron gas is in fair agreement with the Lindhard model.
给出了在中等到高入射粒子能量下，沿硅主轴向沟道化的（4）He和（7）Li离子的电子能量损失测量结果。巴卡斯效应，即在高能量下与入射粒子电荷的三次方成正比的能量损失增强，与其他过程明显区分开来。对于沿硅[110]方向沟道化的锂离子，该效应达到约50%。从价电子气中观察到的巴卡斯贡献与林哈德模型相当吻合。
