欧内斯特·劳伦斯是卡尔和冈达·劳伦斯的长子,他们都是挪威血统的教育家。他在后来成为成功科学家的人周围长大:他的弟弟约翰与他合作研究回旋加速器的医学应用,他童年最好的朋友梅尔·图夫是一位开拓性的物理学家。劳伦斯就读于广州高中,然后在明尼苏达州的圣奥拉夫学院学习一年,然后转入南达科他大学。在那里,他获得了化学学士学位,毕业于1922。最初,劳伦斯是一名预科生,在刘易斯·阿克利的鼓励下,他转学了物理,刘易斯·阿克利是该大学的院长兼物理和化学教授。作为劳伦斯一生中颇具影响力的人物,阿克利院长的照片后来会挂在劳伦斯办公室的墙上,这个画廊里有著名的科学家,如尼尔斯·玻尔和欧内斯特·卢瑟福。劳伦斯1923年在明尼苏达大学获得物理学硕士学位,1925年在耶鲁大学获得博士学位。他在耶鲁又待了三年,最初是研究员,后来是助理教授,1928年成为加州大学伯克利分校的副教授。1930年,29岁的劳伦斯成为伯克利的“正式教授”——有史以来最年轻的获得该称号的教员。劳伦斯仔细研究了挪威工程师罗尔夫·维德罗的一篇论文中的图表后,提出了回旋加速器的想法。Wideroe的论文描述了一种装置,它可以通过在两个线性电极之间“推”来产生高能粒子。然而,将粒子加速到足够高的能量用于研究将需要太长的线性电极,而不能容纳在实验室中。劳伦斯认识到,圆形加速器,而不是线性加速器,可以采用类似的方法来加速带电粒子的螺旋图案。劳伦斯和他的一些第一批研究生一起研制了回旋加速器,包括尼尔斯·埃德莱夫森和斯坦利·利文斯顿。Edlefsen帮助开发了回旋加速器的第一个概念验证:一个10厘米的圆形装置,由青铜、蜡和玻璃制成。随后的回旋加速器更大,能够将粒子加速到越来越高的能量。在1946完成的回旋加速器大约比第一个大50倍。它需要一块重达4000吨的磁铁和一座直径160英尺、高100英尺的建筑物。第二次世界大战期间,劳伦斯致力于曼哈顿项目,帮助研制原子弹。原子弹需要铀的“可裂变”同位素铀-235,并且需要从铀-238上分离出来。劳伦斯提出,由于这两种同位素的质量差别很小,所以可以分开,并开发了一种叫做“calutrons”的工作装置,可以电磁分离这两种同位素。

澳大利亚莫纳什大学Essay代写:电磁分离

Ernest Lawrence is the eldest son of Karl and Gonda Lawrence, both educators of Norwegian origin. He grew up around people who later became successful scientists: his brother John worked with him on the medical applications of cyclotrons, and his best friend in childhood, Mel Tuff, was a pioneering physicist. Lawrence studied at Guangzhou High School, then at St. Olaf College in Minnesota for a year, and then transferred to the University of South Dakota. There, he received a bachelor’s degree in chemistry and graduated in 1922. Initially, Lawrence was a preparatory student. Encouraged by Lewis Ackley, he transferred to physics. Lewis Ackley is the president and professor of physics and chemistry of the university. As an influential figure in Lawrence’s life, President Ackley’s photograph will later hang on the wall of Lawrence’s office, where famous scientists such as Neil Bohr and Ernest Rutherford are in the gallery. Lawrence received his master’s degree in physics from the University of Minnesota in 1923 and his doctorate from Yale University in 1925. He stayed at Yale for another three years, first as a researcher, then as an assistant professor, and in 1928 became an associate professor at the University of California, Berkeley. In 1930, Lawrence, 29, became Berkeley’s “full professor” – the youngest teacher ever to win the title. Lawrence studied the charts in a paper by Norwegian Engineer Rolf Videro and came up with the idea of cyclotron. Wideroe’s paper describes a device that generates energetic particles by “pushing” between two linear electrodes. However, accelerating the particles to sufficiently high energy for research would require too long a linear electrode to accommodate in the laboratory. Lawrence realized that a circular accelerator, rather than a linear accelerator, could use a similar method to accelerate the spiral pattern of charged particles. Lawrence and some of his first graduate students developed cyclotrons, including Niels Edlevson and Stanley Livingston. Edlefsen helped develop the first proof of concept for cyclotrons: a 10-centimeter circular device made of bronze, wax and glass. Subsequently, the cyclotron is larger and can accelerate particles to higher and higher energies. The cyclotron completed in 1946 was about 50 times larger than the first. It needs a magnet weighing 4,000 tons and a building 160 feet in diameter and 100 feet in height. During World War II, Lawrence worked on the Manhattan Project to help develop the atomic bomb. Atomic bombs require a fissile uranium isotope, uranium-235, and need to be separated from uranium-238. Lawrence proposed that the two isotopes could be separated because of their small mass differences. A working device called “calutrons” was developed to separate the two isotopes electromagnetically.

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