Intense gamma-ray source based on focused electron beams from a laser wakefield accelerator
Intense gamma-ray source based on focused electron beams from a laser wakefield accelerator
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DOI：
10.1063/5.0095576
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发表时间：
2022-06
影响因子：
4
通讯作者：
V. Senthilkumaran;D. Bailie;K. Behm;J. Warwick;G. M. Samarin;A. Maksimchuk;J. Nees;A. Thomas;G. Sarri;K. Krushelnick;A. Hussein
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作者：
V. Senthilkumaran;D. Bailie;K. Behm;J. Warwick;G. M. Samarin;A. Maksimchuk;J. Nees;A. Thomas;G. Sarri;K. Krushelnick;A. Hussein
激光韦克菲尔德加速器产生超短电子聚束，具有产生γ射线的能力。在这里，我们使用三个四极磁铁产生聚焦的激光韦克菲尔德加速电子束。然后，电子束被聚焦到一个3 mm的铅转换器中，以产生强的、聚焦的韧致辐射γ束。用铜堆量能器测量了聚焦γ束的产生和传输，得到最佳聚焦光斑尺寸为2.3 ± 0.1 × 2.7 ± 0.2mm ~ 2。使用GEANT 4进行的蒙特卡罗模拟与实验结果吻合良好，并能够详细检查γ射线的产生。模拟结果表明，聚焦后的γ束在100 keV ~ 33 MeV范围内包含2.6 × 109个光子，平均能量为6.4 MeV。根据模拟结果估计γ射线强度为7 × 1010 W/cm 2。聚焦韧致辐射γ射线源的产生在医学成像应用和实验室天体物理实验中具有重要的应用。
Laser wakefield accelerators generate ultrashort electron bunches with the capability to produce γ-rays. Here, we produce focused laser wakefield acceleration electron beams using three quadrupole magnets. Electron beams are then focused into a 3 mm lead converter to generate intense, focused bremsstrahlung γ beams. Experimental results demonstrate the generation and propagation of focused γ beams to a best focus spot size of 2.3 ± 0.1 × 2.7 ± 0.2 mm2 using a copper stack calorimeter. Monte Carlo simulations conducted using GEANT4 are in good agreement with experimental results and enable detailed examination of γ-ray generation. Simulations indicate that the focused γ beams contained 2.6 × 109 photons in the range of 100 keV to 33 MeV with an average energy of 6.4 MeV. A γ-ray intensity of 7 × 1010 W/cm2 was estimated from simulations. The generation of focused bremsstrahlung γ-ray sources can have important applications in medical imaging applications and laboratory astrophysics experiments.