求翻译！求讲解
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一种新的微波武器——Maser（激微波）介绍
这个是我在维基查阅激光词条无意中找到的~~~~~~~~~~~~~~~~~~~~~~~~~~
激微波
(
MASER，或者音译为
迈射）是
受激放大微波辐射（
Microwave Amplification by Stimulated Emission of Radiation）的头字母。它指通过受激辐射放大和必要的反馈，产生同一波宽、准直、相干的
微波的过程及仪器。
鉴于这玩意的国内中文方面的详细介绍几乎没有，在此将直接引用维基百科的英文介绍：
鉴于网上的大多数翻译不靠谱，要翻译的话，请自行~~~~~~~~~
+
From Wikipedia, the free encyclopedia.
For other uses, see
Maser (disambiguation).
A
maser is a device that produces
coherent
electromagnetic wavesthrough amplification by
stimulated emission. Historically, “maser” derives from the original, upper-case acronym
MASER, which stands for "
Microwave
Amplification by
Stimulated Emission of
Radiation". The lower-case usage arose from technological development having rendered the original denotation imprecise, because contemporary masers emit EM waves (
microwave and
radio frequencies) across a broader band of the
electromagnetic spectrum; thus, the
physicist
Charles H. Townes’s suggested usage of “
molecular” replacing “microwave”, for contemporary linguistic accuracy.
[1] In 1957, when the optical coherent oscillator was first developed, it was denominated
optical maser, but usually called
laser (Light Amplification by Stimulated Emission of Radiation), the acronym
Gordon Gould established in 1957.
History
The theoretical principles describing the operation of a maser was described by Nikolay Basov and Alexander Prokhorov from Lebedev Institute of Physics at an All-Union Conference on Radio-Spectroscopy held by USSR Academy of Sciences in May 1952.
The results were subsequently published in October 1954. A precursor of the maser was the first show boostedhydrogen device built and tested by physicists Theodor V. Ionescu and Vasile Mihu in 1946. Independently, Charles H. Townes, J. P. Gordon, and H. J. Zeiger built the first ammonia maser at Columbia University in 1953. The device used stimulated emission in a stream of energized ammonia molecules to produce amplification ofmicrowaves at a frequency of 24 gigahertz.
Townes later worked with Arthur L. Schawlow to describe the principle of the optical maser, or laser, whichTheodore H. Maiman first demonstrated in 1960. For their research in this field Townes, Basov, and Prokhorov were awarded the Nobel Prize in Physics in 1964.
Technology
The maser is based on the principle of stimulated emission proposed by Albert Einstein in 1917. When atoms have been induced into an excited energy state, they can amplify radiation at the proper frequency. By putting such an amplifying medium in a resonant cavity, feedback is created that can produce coherent radiation.
[blockquote][edit][/blockquote]Some common types of masers
Uses
Masers serve as high precision frequency references. These "atomic frequency standards" are one of the many forms of atomic clocks. They are also used as electronic amplifiers in radio telescopes. Masers are being developed as directed-energy weapons.
Hydrogen maser
Main article: Hydrogen maser
Today, the most important type of maser is the hydrogen maser which is currently used as an atomic frequency standard. Together with other types of atomic clocks, they constitute the "Temps Atomique International" or TAI. This is the international time scale, which is coordinated by the Bureau International des Poids et Mesures, or BIPM.
It was Norman Ramsey and his colleagues who first realized this device. Today's masers are identical to the original design. The maser oscillation relies on stimulated emission between two hyperfine levels of atomic hydrogen. Here is a brief description of how it works:
Astrophysical masers
Main article: Astrophysical maser
Maser-like stimulated emission also occurs in nature in interstellar space, and is frequently calledsuperradiant emission to distinguish it from laboratory masers. Such emission is observed from molecules such as water (H2O), hydroxyl radicals (OH), methanol (CH3OH), formaldehyde (CH2O), and silicon monoxide (SiO). Water molecules in star-forming regions can undergo a population inversion and emit radiation at 22 GHz, creating the brightest spectral line in the radio universe. Some water masers also emit radiation from a vibrational mode at 96 GHz.
Extremely powerful masers, associated with active galactic nuclei, are known as megamasers and are up to a million times more powerful than stellar masers.
Terminology
The meaning of the term maser has changed slightly since its introduction. Initially the acronym was universally given as "microwave amplification by stimulated emission of radiation," which described devices which emitted in the microwave region of the electromagnetic spectrum.
The principle and concept of stimulated emission has since been extended to more devices and frequencies. Thus the original acronym is sometimes modified, as suggested by Charles H. Townes,[1] to "molecular amplification by stimulated emission of radiation." Some have asserted that Townes's efforts to extend the acronym in this way were primarily motivated by the desire to increase the importance of his invention, and his reputation in the scientific community.[3]
When the laser was developed, Townes and Schawlow and their colleagues at Bell Labs pushed the use of the termoptical maser, but this was largely abandoned in favor of laser, coined by their rival Gordon Gould.[4] In modern usage, devices that emit in the X-ray through infrared portions of the spectrum are typically calledlasers, and devices that emit in the microwave region and below are commonly called masers, regardless of whether they emit microwaves or other frequencies.
Gould originally proposed distinct names for devices that emit in each portion of the spectrum, includinggrasers (gamma ray lasers), xasers (x-ray lasers), uvasers (ultraviolet lasers), lasers (visible lasers),irasers (infrared lasers), masers (microwave masers), and rasers (RF masers). Most of these terms never caught on, however, and all have now become (apart from in science fiction) obsolete except for maser and laser.
In the early 1960s JPL developed a Maser to provide ultra low noise amplification of S band signals received from deep space probes. This Maser used refrigerated Hydrogen to chill the amplifier to four degrees Kelvin. Amplification was achieved by exciting a ruby comb with a 12 GHz Klystron. In the early days it took days to chill [and remove impurities from] the Hydrogen lines. Refrigeration was two stage with a large Linde unit on the ground and a crosshead compressor within the antenna; final injection was at 3000psi through a six thou inch [micrometer adjustable] entry to the chamber. The whole system noise temperature looking at cold sky [2.7K] was 17 degrees K. This gave such a low noise figure that the Mariner 64 Spacecraft could send pictures of Mars back to Earth even though the spacecraft transmitter was only 15 Watts and the signal received was -169 dbm
![200px-Hmaser.svg.png]()
![260px-Hydrogen_maser.gif]()
![maser-.gif]()
![maser_h2.jpg]()
摘自：XXXXXXXXXXXXXXXXXXXXXXX/wiki/Maser [i]
[/b]
激微波
鉴于这玩意的国内中文方面的详细介绍几乎没有，在此将直接引用维基百科的英文介绍：
鉴于网上的大多数翻译不靠谱，要翻译的话，请自行~~~~~~~~~
+
From Wikipedia, the free encyclopedia.
For other uses, see
A
History
The theoretical principles describing the operation of a maser was described by Nikolay Basov and Alexander Prokhorov from Lebedev Institute of Physics at an All-Union Conference on Radio-Spectroscopy held by USSR Academy of Sciences in May 1952.
The results were subsequently published in October 1954. A precursor of the maser was the first show boostedhydrogen device built and tested by physicists Theodor V. Ionescu and Vasile Mihu in 1946. Independently, Charles H. Townes, J. P. Gordon, and H. J. Zeiger built the first ammonia maser at Columbia University in 1953. The device used stimulated emission in a stream of energized ammonia molecules to produce amplification ofmicrowaves at a frequency of 24 gigahertz.
Townes later worked with Arthur L. Schawlow to describe the principle of the optical maser, or laser, whichTheodore H. Maiman first demonstrated in 1960. For their research in this field Townes, Basov, and Prokhorov were awarded the Nobel Prize in Physics in 1964.
Technology
The maser is based on the principle of stimulated emission proposed by Albert Einstein in 1917. When atoms have been induced into an excited energy state, they can amplify radiation at the proper frequency. By putting such an amplifying medium in a resonant cavity, feedback is created that can produce coherent radiation.
[blockquote][edit][/blockquote]Some common types of masers
- Atomic beam masers
- Ammonia maserFree electron maserHydrogen maser
- Rubidium maser
- Ruby maserWhispering-gallery modes iron-sapphire maser
Uses
Masers serve as high precision frequency references. These "atomic frequency standards" are one of the many forms of atomic clocks. They are also used as electronic amplifiers in radio telescopes. Masers are being developed as directed-energy weapons.
Hydrogen maser
Main article: Hydrogen maser
Today, the most important type of maser is the hydrogen maser which is currently used as an atomic frequency standard. Together with other types of atomic clocks, they constitute the "Temps Atomique International" or TAI. This is the international time scale, which is coordinated by the Bureau International des Poids et Mesures, or BIPM.
It was Norman Ramsey and his colleagues who first realized this device. Today's masers are identical to the original design. The maser oscillation relies on stimulated emission between two hyperfine levels of atomic hydrogen. Here is a brief description of how it works:
- First, a beam of atomic hydrogen is produced. This is done by submitting the gas at low pressure to an RF discharge (see the picture on this page).
- The next step is "state selection"—in order to get some stimulated emission, it is necessary to create a population inversion of the atoms. This is done in a way that is very similar to the famous Stern-Gerlach experiment. After passing through an aperture and a magnetic field, many of the atoms in the beam are left in the upper energy level of the lasing transition. From this state, the atoms can decay to the lower state and emit some microwave radiation.
- A high quality factor microwave cavity confines the microwaves and reinjects them repeatedly into the atom beam. The stimulated emission amplifies the microwaves on each pass through the beam. This combination of amplificationand feedback is what defines all oscillators. The resonant frequency of the microwave cavity is exactly tuned to the hyperfine structure of hydrogen: 1420 405 751.768 Hz.
- A small fraction of the signal in the microwave cavity is coupled into a coaxial cable and then sent to a coherent receiver.
- The microwave signal coming out of the maser is very weak (a few pW). The frequency of the signal is fixed and extremely stable. The coherent receiver is used to amplify the signal and change the frequency. This is done using a series of phase-locked loops and a high performance quartz oscillator.
Astrophysical masers
Main article: Astrophysical maser
Maser-like stimulated emission also occurs in nature in interstellar space, and is frequently calledsuperradiant emission to distinguish it from laboratory masers. Such emission is observed from molecules such as water (H2O), hydroxyl radicals (OH), methanol (CH3OH), formaldehyde (CH2O), and silicon monoxide (SiO). Water molecules in star-forming regions can undergo a population inversion and emit radiation at 22 GHz, creating the brightest spectral line in the radio universe. Some water masers also emit radiation from a vibrational mode at 96 GHz.
Extremely powerful masers, associated with active galactic nuclei, are known as megamasers and are up to a million times more powerful than stellar masers.
Terminology
The meaning of the term maser has changed slightly since its introduction. Initially the acronym was universally given as "microwave amplification by stimulated emission of radiation," which described devices which emitted in the microwave region of the electromagnetic spectrum.
The principle and concept of stimulated emission has since been extended to more devices and frequencies. Thus the original acronym is sometimes modified, as suggested by Charles H. Townes,[1] to "molecular amplification by stimulated emission of radiation." Some have asserted that Townes's efforts to extend the acronym in this way were primarily motivated by the desire to increase the importance of his invention, and his reputation in the scientific community.[3]
When the laser was developed, Townes and Schawlow and their colleagues at Bell Labs pushed the use of the termoptical maser, but this was largely abandoned in favor of laser, coined by their rival Gordon Gould.[4] In modern usage, devices that emit in the X-ray through infrared portions of the spectrum are typically calledlasers, and devices that emit in the microwave region and below are commonly called masers, regardless of whether they emit microwaves or other frequencies.
Gould originally proposed distinct names for devices that emit in each portion of the spectrum, includinggrasers (gamma ray lasers), xasers (x-ray lasers), uvasers (ultraviolet lasers), lasers (visible lasers),irasers (infrared lasers), masers (microwave masers), and rasers (RF masers). Most of these terms never caught on, however, and all have now become (apart from in science fiction) obsolete except for maser and laser.
In the early 1960s JPL developed a Maser to provide ultra low noise amplification of S band signals received from deep space probes. This Maser used refrigerated Hydrogen to chill the amplifier to four degrees Kelvin. Amplification was achieved by exciting a ruby comb with a 12 GHz Klystron. In the early days it took days to chill [and remove impurities from] the Hydrogen lines. Refrigeration was two stage with a large Linde unit on the ground and a crosshead compressor within the antenna; final injection was at 3000psi through a six thou inch [micrometer adjustable] entry to the chamber. The whole system noise temperature looking at cold sky [2.7K] was 17 degrees K. This gave such a low noise figure that the Mariner 64 Spacecraft could send pictures of Mars back to Earth even though the spacecraft transmitter was only 15 Watts and the signal received was -169 dbm
摘自：XXXXXXXXXXXXXXXXXXXXXXX/wiki/Maser [i]
[/b]
这东西国内的翻译叫微波激射器，出现的比激光更早，后人在它的启示下才发明激光。
它产生的微波振荡频率取决于介质的能级，频率非常稳定准确，一开始就被用作基准时钟以及特定频率的放大器。
最初用氨作为增益介质，称为氨分子钟，后来发展到铯原子钟、铷原子钟。
和激光一样，微波激射器发出一个光子需要介质能级跃迁一次，但一个微波光子的能量远小于一个可见光子。
虽然只利用很小一部分能级，但用放电激发介质时一般仍会将介质激发到较高的激发态，消耗的能量不比激光少。
因此它在跃迁次数相同的情况下发光的功率和效率比激光低的多，只适合用于精密信号处理，不适合做大功率。
它产生的微波振荡频率取决于介质的能级，频率非常稳定准确，一开始就被用作基准时钟以及特定频率的放大器。
最初用氨作为增益介质，称为氨分子钟，后来发展到铯原子钟、铷原子钟。
和激光一样，微波激射器发出一个光子需要介质能级跃迁一次，但一个微波光子的能量远小于一个可见光子。
虽然只利用很小一部分能级，但用放电激发介质时一般仍会将介质激发到较高的激发态，消耗的能量不比激光少。
因此它在跃迁次数相同的情况下发光的功率和效率比激光低的多，只适合用于精密信号处理，不适合做大功率。
引用
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回 5楼(银色荆棘) 的帖子
但效率也一定比現行激光武器低得多。你覺得處理微弱信號爲主的東西放大功率之後，除了成爲電老虎之外還有別的作爲麽？
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微波激射器。至迟1960年之前就有了。比激光早。基于经过筛选的分子束。能级非常小，只到微波频率。费曼物理学讲义（成书于1962年前后）第三册有一章对此有过详细介绍。
引用
2
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来自免费百科全书维基百科。
有关其他用途，请参见
Maser（消歧义）。
A.
微波激射器是一种产生
连贯的
电磁波通过放大
受激发射。从历史上看，“maser”源自原始的大写首字母缩略词
MASER，代表“
微波炉
放大
受激发射
“辐射”。小写的用法源于技术的发展，因为现代微波激射器发射电磁波，使得原始的表示变得不精确(
微波和
无线电频率）
电磁频谱；因此
物理学家
Charles XXXXwnes建议使用“
“分子”取代“微波”，以提高当代语言的准确性。
[1] 1957年，当光学相干振荡器首次开发时，它被命名为
光学脉泽，但通常称为
激光（受激辐射光放大），缩写
戈登·古尔德成立于1957年。
历史
1952年5月，列别捷夫物理研究所的尼古拉·巴索夫（Nikolay Basov）和亚历山大·普罗霍罗夫（Alexander Prokhorov）在苏联科学院举行的全联盟无线电光谱学会议上描述了描述微波激射器运行的理论原理。
结果随后于1954年10月发表。微波激射器的前身是物理学家西奥多·V·伊奥尼斯库（Theodor XXXXnescu）和瓦西里尔·米胡（Vasile Mihu）于1946年建造并测试的第一台演示氢装置。1953年，查尔斯·H·汤森斯（Charles XXXXwnes）、J·P·戈登（J.P.Gordon）和H·J·齐格（H.J.Zeiger）在哥伦比亚大学独立建造了第一台氨微波激射。该装置利用通电的氨分子流中的受激发射产生频率为24千兆赫兹的微波放大。
Townes后来与Arthur XXXXhawlow合作，描述了西奥多·H·迈曼（Theodore XXXXiman）于1960年首次演示的光学脉泽（或激光）的原理。Townes、Basov和Prokhorov因在这一领域的研究于1964年获得了诺贝尔物理学奖。
技术
微波激射器基于阿尔伯特·爱因斯坦在1917年提出的受激发射原理。当原子被诱导进入激发能态时，它们可以以适当的频率放大辐射。通过将这种放大介质放在谐振腔中，产生了可以产生相干辐射的反馈。
[blockquote][edit][/blockquote]一些常见类型的脉泽
原子束脉泽
氨脉泽自由电子脉泽氢脉泽
气体脉泽
铷脉泽
固态微波激射器
红宝石脉泽低语画廊模式铁蓝宝石脉泽
非极性掩蔽介质的双重惰性气体。[2]
使用
激射器用作高精度频率基准。这些“原子频率标准”是原子钟的多种形式之一。它们也被用作射电望远镜的电子放大器。激射器正被开发为定向能武器。
氢脉泽
主要文章：氢脉泽
今天，最重要的微波激射器类型是氢微波激射，它目前被用作原子频率标准。它们与其他类型的原子钟一起构成了“Temps Atomique International”或TAI。这是国际时间尺度，由国际计量局（BIPM）协调。
是诺曼·拉姆齐和他的同事首次实现了这一设备。今天的微波激射器与最初的设计完全相同。脉泽振荡依赖于两个超精细氢原子能级之间的受激发射。以下是对其工作原理的简要描述：
首先，产生一束原子氢。这是通过将气体在低压下进行射频放电来实现的（参见本页图片）。
下一步是“状态选择”——为了获得一些受激发射，有必要创建原子的布居反转。这是以一种非常类似于著名的Stern Gerlach实验的方式完成的。在通过孔径和磁场后，光束中的许多原子留在激光跃迁的高能级。从这个状态，原子可以衰变到较低的状态，并发射一些微波辐射。
一个高质量因数的微波腔限制了微波，并将其反复注入原子束。受激发射在每次通过光束时放大微波。这种放大和反馈的组合定义了所有振荡器。微波腔的谐振频率精确地调谐到氢的超精细结构：1420 405 751.768 Hz。
微波腔中的一小部分信号被耦合到同轴电缆中，然后被发送到相干接收器。
微波激射器发出的微波信号非常微弱（几pW）。信号的频率是固定的并且非常稳定。相干接收机用于放大信号并改变频率。这是使用一系列锁相环和高性能石英振荡器完成的。
天体物理脉泽
主要文章：天体物理脉泽
类似激射器的受激发射也发生在星际空间的自然界中，并经常被称为超辐射发射，以区别于实验室激射器。从诸如水（H2O）、羟基自由基（OH）、甲醇（CH3OH）、甲醛（CH2O）和一氧化硅（SiO）的分子中观察到这种发射。恒星形成区的水分子可以经历种群反转，并发射22 GHz的辐射，创造出无线电宇宙中最亮的谱线。一些水脉泽也发射96GHz振动模式的辐射。
与活动星系核相关的极强的脉泽被称为巨型脉泽，其功率比恒星脉泽大一百万倍。
术语
“微波激射”一词的含义自引入以来略有变化。最初，首字母缩略词被普遍称为“受激辐射的微波放大”，它描述了在电磁频谱的微波区域发射的设备。
受激发射的原理和概念已经扩展到更多的设备和频率。因此，正如查尔斯·H·汤森（Charles XXXXwnes）所建议的，最初的首字母缩略词有时会被修改为“通过受激辐射的分子放大”。一些人断言，汤森以这种方式扩展首字母缩略语的努力主要是出于提高其发明的重要性和他在科学界的声誉的愿望。[3]
当激光器被开发出来时，Townes和Schawlow以及他们在贝尔实验室的同事推动了“光学脉泽”一词的使用，但这一术语在很大程度上被放弃，取而代之的是他们的竞争对手戈登·古尔德（Gordon Gould）创造的激光。[4] 在现代使用中，通过光谱的红外部分发射X射线的装置通常被称为激光激射器，而在微波区域及以下发射的装置通常称为微波激射器（maser），无论它们发射的是微波还是其他频率。
古尔德最初为在光谱的每一部分发射的设备提出了不同的名称，包括伽马射线激光（gamma ray laser）、x射线激光（xasers）、紫外激光（uvaser）、激光（可见激光）、红外激光（irasers）和微波激射器（微波激射）。然而，这些术语中的大多数从未流行过，除微波激射器和激光外，所有这些术语现在都已过时（科幻小说除外）。
20世纪60年代初，JPL开发了一种激射器，用于对从深空探测器接收的S波段信号进行超低噪声放大。该Maser使用冷冻氢气将放大器冷却至4开尔文。放大是通过用12GHz速调管激发红宝石梳实现的。在早期，需要几天的时间来冷却氢气管线（并去除其中的杂质）。制冷分为两个阶段，地面上有一个大型林德装置，天线内有一个十字头压缩机；最后一次注射是在3000磅/平方英寸的压力下，通过6000英寸（微米可调）的入口进入腔室。在寒冷的天空中，整个系统的噪声温度[2.7K]为17摄氏度。这给出了一个非常低的噪声值，即使太空船发射器只有15瓦，接收到的信号为-169分贝，水手64号太空船也能将火星的照片传回地球。
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