Zeil K, Kraft S D, Jochmann A, Kroll F, Jahr W, Schramm U, Karsch L, Pawelke J, Hidding B, Pretzler G
Forschungszentrum Dresden-Rossendorf (FZD), Dresden 01314, Germany.
Rev Sci Instrum. 2010 Jan;81(1):013307. doi: 10.1063/1.3284524.
The characterization of the absolute number of electrons generated by laser wakefield acceleration often relies on absolutely calibrated FUJI imaging plates (IP), although their validity in the regime of extreme peak currents is untested. Here, we present an extensive study on the dependence of the sensitivity of BAS-SR and BAS-MS IP to picosecond electron bunches of varying charge of up to 60 pC, performed at the electron accelerator ELBE, making use of about three orders of magnitude of higher peak intensity than in prior studies. We demonstrate that the response of the IPs shows no saturation effect and that the BAS-SR IP sensitivity of 0.0081 photostimulated luminescence per electron number confirms surprisingly well data from previous works. However, the use of the identical readout system and handling procedures turned out to be crucial and, if unnoticed, may be an important error source.
激光尾场加速产生的电子绝对数量的表征通常依赖于经过绝对校准的富士成像板（IP），尽管其在极端峰值电流 regime 下的有效性尚未经过测试。在此，我们进行了一项广泛的研究，研究了 BAS - SR 和 BAS - MS IP 对电荷高达 60 pC 的皮秒电子束的灵敏度依赖性，该研究在电子加速器 ELBE 上进行，利用的峰值强度比先前研究高约三个数量级。我们证明，IP 的响应没有饱和效应，并且每电子数 0.0081 光激发发光的 BAS - SR IP 灵敏度与先前工作的数据惊人地吻合。然而，事实证明使用相同的读出系统和处理程序至关重要，如果被忽视，可能是一个重要的误差来源。
