利用強短脈衝雷射與大面積懸浮式石墨烯交互作用產生質子加速;Proton Acceleration with Intense Short Pulse Lasers Interacting with Large-Area Suspended Graphene

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/74276

Title:	利用強短脈衝雷射與大面積懸浮式石墨烯交互作用產生質子加速;Proton Acceleration with Intense Short Pulse Lasers Interacting with Large-Area Suspended Graphene
Authors:	諾嘉薩娜;Khasanah, Nur
Contributors:	物理學系
Keywords:	磁場;質子加速;雷射;懸浮式石墨烯;Magnetic field;Proton acceleration;Laser;Suspended graphene
Date:	2017-07-24
Issue Date:	2017-10-27 13:41:25 (UTC+8)
Publisher:	國立中央大學
Abstract:	磁重聯在宇宙中扮演著一個基本的腳色，如：磁層次風暴、極光、恆星、太陽閃焰與太陽風。實驗室天文學是一個研究太空與天文現象的完備的工具。我們利用高強度雷射照射在固態靶材上以觀測磁重聯現象。在本實驗中，我們觀測由雷射產生之磁重聯電漿在空間與時間上的演化。磁場測量在未來的實驗中是必須的。質子射線照相術是量測與成像雷射產生電漿中電場與磁場的主要診斷方法。質子束可以透過高度雷射照射薄靶才來產生。高能輻射會因為雷射驅動相對論性電子震盪與靶才物質的原子核相互作用而在寬廣的方向放出。在相對小的雷射設施，如中央大學一百兆瓦雷射，輻射防護會因為有限的空間與樓層建築強度而變成很嚴重的問題。為了要減少輻射的問題，我們必須減少游離體積中的原子數。因此我們減少靶材厚度與並選擇低原子數的材質。石墨烯是理想的選擇。因此我們發展了懸浮的石墨烯靶才來抑制輻射。大面積的懸浮式石墨烯靶受到高強度短脈衝的雷射照射。被加速的質子透過一堆變色薄膜來記錄。使用 2 奈米與 4 奈米的懸浮式石墨烯，在第五層薄膜可以觀察到訊號，其所對應的碳的能量為160 MeV。結果顯示懸掛式石墨烯靶把能量推進到足夠在未來做雷射電漿交互作用的研究。;Magnetic reconnection plays a fundamental role in the universe, such as magnetospheric substorms, aurorae, stellar and solar flares and their winds. Laboratory experiments can be a complemental tool to investigate space and astrophysical phenomena. We have observed the magnetic reconnection by irradiating a solid target with high-power laser beams. In these experiment, we observed the spatial and temporal plasma evolutions of magnetic reconnection in laser produced plasmas. Magnetic field measurement is needed in the future experiment. Proton radiography is a key diagnostic to measure and image the electric/magnetic field in laser produced plasmas. A thin solid target is irradiated with an intense laser pulse to produce a proton beam. High energy radiations are emitted in wide direction due to the interaction between the forced oscillating relativistic electrons by the laser electric field and the nuclei of target material. At relatively small laser facilities, such as the NCU 100 TW laser facility, the radiation protections can be a serious practical problem due to the limited space and the floor strength of the building. In order to suppress radiation, we need to reduce the number of atoms in the ionized volume. To this end, we reduce the target thickness and choose the low atomic number material. The suspended graphene is an ideal solution for this. Therefore, we have developed suspended graphene target to suppress the radiations. Large-area suspended graphene targets were exposed with intense short pulse laser. Accelerated ions were recorded with a stack of Radiochromic film (RCF). Using a 2 nm and 4 nm suspended graphene, one can see a signal in the 5th film, which corresponds to carbon energy of 160 MeV. The results of this thesis show that suspended graphene is robust enough to be used in future studies of laser plasma interaction.
Appears in Collections:	[Graduate Institute of Physics] Electronic Thesis & Dissertation

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