Cayzac Witold, Frank Alexander, Schumacher Dennis, Roth Markus, Blazević Abel, Wamers Felix, Träger Michael, Berdermann Elèni, Voss Bernd, Hessling Thomas
Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany.
Rev Sci Instrum. 2013 Apr;84(4):043301. doi: 10.1063/1.4798539.
This article reports on the development and the first applications of a new spectrometer which enables the precise and time-resolved measurement of both the energy loss and the charge-state distribution of ion beams with 10 < Z < 30 at energies of 4-8 MeV/u after their interaction with a laser-generated plasma. The spectrometer is based on five 20 × 7 mm(2) large and 20 μm thick polycrystalline diamond samples produced via the Chemical Vapour Deposition (CVD) process and was designed with the help of ion-optical simulations. First experiments with the spectrometer were successfully carried out at GSI using (48)Ca ions at an energy of 4.8 MeV/u interacting with a carbon plasma generated by the laser irradiation of a thin foil target. Owing to the high rate capability and the short response time of the spectrometer, pulsed ion beams with 10(3)-10(4) ions per bunch at a bunch frequency of 108 MHz could be detected. The temporal evolution of the five main charge states of the calcium ion beams as well as the corresponding energy loss values could be measured simultaneously. Due to the outstanding properties of diamond as a particle detector, a beam energy resolution ΔEE ≈ 0.1% could be reached using the presented experimental method, while a precision of 10% in the energy loss and charge-state distribution data was obtained.
本文报道了一种新型光谱仪的研制及其首次应用。该光谱仪能够精确且具有时间分辨地测量能量为4 - 8 MeV/u、原子序数10 < Z < 30的离子束与激光产生的等离子体相互作用后的能量损失和电荷态分布。该光谱仪基于通过化学气相沉积（CVD）工艺制备的五个20×7 mm²大、20μm厚的多晶金刚石样品，并借助离子光学模拟进行设计。利用能量为4.8 MeV/u的（48）Ca离子与薄箔靶激光辐照产生的碳等离子体相互作用，在GSI成功进行了该光谱仪的首次实验。由于该光谱仪具有高计数率能力和短响应时间，能够检测每束含10³ - 10⁴个离子、束频率为108 MHz的脉冲离子束。可以同时测量钙离子束五个主要电荷态的时间演化以及相应的能量损失值。由于金刚石作为粒子探测器具有优异性能，采用本文所述实验方法可实现束能量分辨率ΔE/E ≈ 0.1%，同时在能量损失和电荷态分布数据方面获得了10%的精度。
