本文選題：重離子核反應(yīng) + 溫度��； 參考：《河南師范大學(xué)》2017年碩士論文

【摘要】：在重離子反應(yīng)中,余核的溫度研究一直是一個比較重要的研究方向。兩體碰撞模型可以用來描述重離子碰撞反應(yīng)系統(tǒng)的演化過程。兩體碰撞模型認(rèn)為重離子反應(yīng)系統(tǒng)經(jīng)歷了壓縮、膨脹等一系列過程,反應(yīng)系統(tǒng)的體積先變小再變大,系統(tǒng)的溫度T伴隨著系統(tǒng)的壓縮、碰撞過程也經(jīng)歷了從高到低的變化。本文的主要內(nèi)容分為兩個部分:第一部分主要提出了一種針對中等質(zhì)量余核的改進的溫度探針。此溫度探針主要利用包含三個等量異位素的等量異位素產(chǎn)額比(IYR)的差來提取余核的溫度。在此溫度探針中,三個等量異位素的結(jié)合能的差△B代替了它們的自由能的差△F。利用改進的等量異位素產(chǎn)額比差的方法分析了 140AMeV ~(40,48)Ca + 9Be (181Ta)和~(58,64)Ni + 9Be(181Ta)炮彈碎裂反應(yīng)的實驗數(shù)據(jù)、1A GeV ~(124,136)Xe + Pb炮彈碎裂反應(yīng)實驗數(shù)據(jù)以及1A GeV ~(112,124)Sn+~(112,124)Sn反應(yīng)中的實驗數(shù)據(jù),提取了這些反應(yīng)所產(chǎn)生的中等質(zhì)量余核的溫度T_(IB)。結(jié)果表明:~(40,48)Ca和~(58,64)Ni反應(yīng)得到的大部分余核的溫度T_(IB)的值處在0.6 MeV到3.5 MeV區(qū)域中;1~(24)Xe和~(112,124)Sn反應(yīng)得到的大部分余核的溫度T_(IB)的值處在0.5 MeV到2.5 MeV區(qū)域中;然而136Xe反應(yīng)得到的大部分余核的溫度T_(IB)的值處在0.5 MeV到4.0 MeV區(qū)域中�？傊�,在本文所研究的反應(yīng)中的中等余核的溫度都比較低。第二部分主要研究了中等質(zhì)量余核的溫度與質(zhì)量數(shù)之間的依賴關(guān)系。研究發(fā)現(xiàn),用改進的等量異位素產(chǎn)額比差的方法分析的最終的余核的溫度值和初始余核的溫度值一樣都符合方程T=C(1-k·A)的分布趨勢(其中C和k是參數(shù))。余核的溫度與質(zhì)量數(shù)A的這種依賴關(guān)系可以解釋為余核的自由能差A(yù)F或者結(jié)合能差A(yù)B與質(zhì)量數(shù)A的關(guān)系。在0.5 MeVT4.0MeV的溫度區(qū)域內(nèi),原子核的自由能差A(yù)F和結(jié)合能差A(yù)B都依賴質(zhì)量數(shù)A,并且符合擬合線方程y=1/[C(1-k·A)]。對于確定的原子核,用改進的等量異位素產(chǎn)額比差的方法提取的在0.5 MeV T 4.0 MeV的溫度區(qū)域內(nèi)的余核的溫度值的分布也符合擬合線方程y = 1 / [C(1 -k·A)]的趨勢。
[Abstract]:In heavy ion reaction, the temperature of conucleus has been an important research direction. The two-body collision model can be used to describe the evolution of heavy ion collision reaction system. The two-body collision model holds that the heavy ion reaction system has undergone a series of processes, such as compression and expansion. The volume of the reaction system first becomes smaller and then becomes larger. The temperature of the system T is accompanied by the compression of the system, and the collision process has undergone a change from high to low. The main contents of this paper are divided into two parts: in the first part, an improved temperature probe for medium mass conuclei is proposed. This temperature probe mainly uses the difference of isometric heterotopic yield ratio (IYR) of three isobaric elements to extract the residual temperature. In this temperature probe, the difference in binding energy of the three isobaric elements B replaces the difference of their free energy. In this paper, the experimental data of the fragmentation reactions of the projectiles of 140AMeV (4048U) Ca 9Be (181Ta) and Ni9Be181Ta() have been analyzed by using the improved method of isobaric yield ratio. The experimental data of the fragmentation reaction of the projectile of 1A GeV / 124136C Xe Pb and 1A GeV 112124Sn / 112124Sn have been analyzed. The temperature of medium mass conucleus produced by these reactions was extracted. The results show that the temperature of most of the residual nuclei produced by the reaction of 40 ~ 40 ~ (48) C ~ (2 +) C ~ (2 +) with Ni is in the range of 0. 6 MeV to 3. 5 MeV. The temperature of most of the residual nuclei obtained from the reaction between 0. 6 MeV and 3. 5 MeV is in the range of 0. 5 MeV to 2. 5 MeV. The temperature of the majority of the residual nuclei obtained by the reaction of 1: 1 212124 ~ Sn is in the range of 0. 5 MeV to 2. 5 MeV. However, the temperature of most of the conuclei obtained by 136Xe reaction is in the range of 0. 5 MeV to 4. 0 MeV. In conclusion, the temperature of the intermediate conuclei in the reactions studied in this paper is relatively low. In the second part, the dependence between temperature and mass number of conuclei with medium mass is studied. It is found that the temperature values of the final conuclei analyzed by the improved isobaric yield ratio method are the same as the temperature values of the initial conuclei (where C and k are the parameters of the equation T=C(1-k A). The dependence of cokernel temperature on mass number A can be explained by the relationship between free energy difference AF or binding energy difference AB and mass number A. In the temperature range of 0. 5 MeVT4.0MeV, the free energy difference (AF) and the binding energy difference (AB) of the nucleus depend on the mass number A. For the determined nuclei, the temperature distribution of the conuclei in the temperature region of 0.5 MeV T 4.0 MeV extracted by the improved isometric heterotopic yield ratio method is also in line with the trend of the fitting line equation y = 1 / [C0. 1 -k A].
【學(xué)位授予單位】：河南師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O571.6

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