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公开(公告)号:US4060769A
公开(公告)日:1977-11-29
申请号:US507877
申请日:1974-09-20
申请人: Philip J. Mallozzi , Harold M. Epstein , David C. Applebaum , William J. Gallagher , Bernerd E. Campbell
发明人: Philip J. Mallozzi , Harold M. Epstein , David C. Applebaum , William J. Gallagher , Bernerd E. Campbell
CPC分类号: H01S3/2316 , H01S3/005 , H01S3/2383
摘要: Methods and apparatus for directing radiation pulses to a region wherein either a pulse or a substance in the region is adversely affected by the presence of more than a given power density therein. A laser pulse is split into a plurality of portions and each portion is directed along a path of different length to provide in rapid succession a plurality of pulses each having less than the given power density. Each pulse is caused to arrive at the region at an angle differing by at least its divergence angle from the arrival angle of every other pulse (or, if at a smaller angle from another pulse, with opposite polarization therefrom) and at a time enough later than the arrival time of the preceding pulse that the total power density in the region at any instant is less than the given power density. Thus, the effective total power density of the radiation directed through the region may exceed the given power density without adversely affecting any pulse or substance in the region. Typically, the region comprises an amplifier from which each pulse emerges at an angle differing by at least its divergence angle from the emergence angle of every other pulse (or, if at a smaller angle from another pulse, with opposite polarization therefrom). Each emerging pulse is separated from the others and is directed along a path of such length as to cause it to arrive at the selected location substantially simultaneously with the other pulses (or, alternatively, at such time relative to the other pulses as to provide a predetermined effective combined pulse shape at the location).
摘要翻译: 用于将辐射脉冲引导到其中该区域中的脉冲或物质的区域中的多于其给定功率密度的存在受到不利影响的区域的方法和装置。 激光脉冲被分成多个部分,并且每个部分沿着不同长度的路径被引导以快速连续地提供多个脉冲,每个脉冲具有小于给定的功率密度。 使每个脉冲以至少其发散角与每隔一个脉冲的到达角相差的角度(或者如果与另一个脉冲以较小的角度与其相反的极化)到达该区域,并且在足够的时间 比前一脉冲的到达时间,任何时刻的区域中的总功率密度小于给定的功率密度。 因此,穿过该区域的辐射的有效总功率密度可以超过给定的功率密度,而不会对该区域中的任何脉冲或物质产生不利影响。 典型地,该区域包括放大器,每个脉冲从该放大器以与每隔一个脉冲的出射角度至少其发散角度不同的角度出现(或者,如果与另一个脉冲以较小的角度与其相反的极化)出现。 每个出现的脉冲与其他脉冲分离,并且沿着这样的长度的路径被引导,以使得其基本上与其他脉冲同时到达所选择的位置(或者,在这样的时间相对于提供一个 在该位置预定的有效组合脉冲形状)。
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公开(公告)号:US4002403A
公开(公告)日:1977-01-11
申请号:US405444
申请日:1973-10-11
申请人: Philip J. Mallozzi , Harold M. Epstein , David C. Applebaum , William J. Gallagher , Bernerd E. Campbell
发明人: Philip J. Mallozzi , Harold M. Epstein , David C. Applebaum , William J. Gallagher , Bernerd E. Campbell
CPC分类号: H01S3/005
摘要: Methods and apparatus for directing a radiation pulse from a laser to a target or other selected location and preventing undesired earlier radiation from the laser having less than a selected intensity from reaching the selected location.A beam splitter directs a major portion of the radiation pulse energy along a longer main path to a predetermined region and continuing on toward the selected location, and directs a minor portion along a shorter secondary path to the predetermined region. A reflective surface on a transparent support in the predetermined region prevents energy having less than the selected intensity from continuing on toward the selected location. The surface comprises a thin layer, as of aluminum, that remains substantially unimpaired until it is subjected to radiation having at least the selected itensity, and then is substantially removed in the area impinged by such radiation, so that when the minor portion of the radiation pulse energy along the shorter secondary path has at least the selected intensity, and thus substantially removes the impinged area of the reflective layer, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the area of removal toward the selected location.Alternatively, the minor energy portion actuates an electrical discharge to vaporize the reflective layer at least substantially.
摘要翻译: 用于将来自激光器的辐射脉冲引导到目标或其他选定位置并防止来自具有小于所选强度的激光器的不期望的较早辐射到达所选择的位置的方法和装置。
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公开(公告)号:US4317994A
公开(公告)日:1982-03-02
申请号:US105816
申请日:1979-12-20
CPC分类号: H05G2/001 , G01N23/063
摘要: Apparatus (10) for obtaining EXAFS data of a material (11). A lens (12) directs a pulse of radiant energy (13) from a laser (14) onto a metal target (15) to produce X-rays (16) of a selected spectrum and intensity at the target (15). A baffle (17) directs X-rays (16) from the target (15) onto a spectral dispersive monochromator (18) which directs the spectrally resolved X-rays (16R) therefrom onto a photographic film 20. A film of material (11) is located in the path (22) of only a portion (16L) of the X-rays (16) throughout a selected spectral band, and the resolved X-rays (16R) directed onto the photographic film (20) form two separate images thereon comprising a reference spectrum (26R) representative of a portion of the X-rays (16U) throughout the selected band that was not affected by the film of material (11) and an absorption spectrum (26A) representative of a portion of the X-rays (16L) throughout the selected band that was modified by transmission through the film of material (11). The laser pulse (13) typically has a width of less than about 10 nanoseconds, and the material (11) may be in a highly transient state.
摘要翻译: 用于获得材料(11)的EXAFS数据的装置(10)。 透镜(12)将来自激光器(14)的辐射能(13)的脉冲引导到金属靶(15)上以产生在目标(15)处选择的光谱和强度的X射线(16)。 挡板(17)将X射线(16)从靶(15)引导到光谱色散单色仪(18)上,光谱色散单色仪(18)将光谱分辨的X射线(16R)引导到照相胶片20上。材料膜(11 )位于仅在X射线(16)的一部分(16L)的整个所选光谱带的路径(22)中,并且指向摄影胶片(20)的分辨X射线(16R)形成两个分开的 其上包括代表不受材料膜(11)影响的整个所选带的X射线(16U)的一部分的参考光谱(26R)的图像和代表材料(11)的一部分的吸收光谱(26A) X射线(16L)遍及通过材料(11)的薄膜传输而被修饰的整个选定的带。 激光脉冲(13)通常具有小于约10纳秒的宽度,并且材料(11)可以处于高度瞬态。
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公开(公告)号:US5131957A
公开(公告)日:1992-07-21
申请号:US676140
申请日:1991-03-26
申请人: Harold M. Epstein , Allan H. Clauer , Boyd A. Mueller , Jeffrey L. Dulaney , Bernerd E. Campbell , Craig T. Walters
发明人: Harold M. Epstein , Allan H. Clauer , Boyd A. Mueller , Jeffrey L. Dulaney , Bernerd E. Campbell , Craig T. Walters
CPC分类号: B23K26/0069 , C21D10/005 , Y10S148/903
摘要: Methods and apparatus for improving properties of a solid material in a target (11) by providing shock waves therein. There are directed to the surface of the material (11) pulses of coherent radiation (12) having average energy fluence of at least about 10 Joules per square centimeter and rise time of not longer than about 5 nanoseconds within a fluorescence envelope lasting about 0.5 to 5 milliseconds, at a rate of about 1 radiation pulse per 100 to 200 microseconds.The leading edge of each pulse (12) is sharpened by providing in its path an aluminum film (18) about 150 to 5000 angstroms thick that is vaporized by the pulse and then is moved across the path so that a later pulse (12) strikes an area of the film (18) not already vaporized by an earlier pulse (12).The radiation (12) is amplified by an amplifier (23) comprising a rod of phosphate laser glass that was strengthened by an ion exchange process.
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