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本文是关于慢正电子束的获得及其应用的文献综述。 (1)能量为1eV左右慢正电子束的获得,通常是用~(22)Na、~(58)Co、~(68)Ga、~(64)Cu作为正电子源;还有用电子直线加速器的电子轰击Ta靶得到脉冲正电子源,由正电子源发射的正电子经慢化器(Cu、W叶片、复式MgO)就可以得到1eV—几百eV的正电子慢化效率极限为10~(-3),一般可达10~(-5)左右。为了使慢正电子单色化还要经一系列电子光学透镜才行。
This article is a literature review of the acquisition and application of slow positron beams. (1) The acquisition of a slow positron beam with an energy of about 1 eV usually takes the use of ~ (22) Na, ~ (58) Co, ~ 68 Ga, ~ 64 Cu as the positron source, Electron bombardment of Ta target to obtain a pulsed positron source, the positron emitted by the positron source by the moderator (Cu, W leaves, double MgO) can be 1eV - a few hundred eV positron-moderation efficiency limit of 10 ~ (-3), generally up to 10 ~ (-5) or so. In order to make slow positron monochromatic also through a series of electronic optical lens Caixing.