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Page "Scintillator" ¶ 66
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wavelength and maximum
These pigments are named after the wavelength ( in nanometers ) of their red-peak absorption maximum.
When the two waves are in phase, i. e. the path difference is equal to an integral number of wavelengths, the summed amplitude, and therefore the summed intensity is maximum, and when they are in anti-phase, i. e. the path difference is equal to half a wavelength, one and a half wavelengths, etc., then the two waves cancel and the summed intensity is zero.
Black body radiation is radiation from an idealized radiator that emits at any temperature the maximum possible amount of radiation at any given wavelength.
A black body will also absorb the maximum possible incident radiation at any given wavelength.
As the wave slows down, the wavelength gets shorter and the amplitude increases ; after a place of maximum response, the short wavelength is associated with a high loss and the wave dies out.
In fiber optics, it is more common to consider the cutoff wavelength, the maximum wavelength that will propagate in an optical fiber or waveguide.
The maximum wavelength that a grating can diffract is equal to twice the grating period, in which case the incident and diffracted light will be at ninety degrees to the grating normal.
A more engineer friendly rule of thumb is that the approximate requirement for spacing loading coils is ten coils per wavelength of the maximum frequency being transmitted.
where λ < sub > 0 </ sub > is the vacuum wavelength of the light, and 2w < sub > 0 </ sub > is the diameter of the beam at its narrowest spot, measured between the 1 / e < sup > 2 </ sup > irradiance points (" Full width at e < sup >− 2 </ sup > maximum of the intensity ").
In telecommunications, spectral width is the wavelength interval over which the magnitude of all spectral components is equal to or greater than a specified fraction of the magnitude of the component having the maximum value.
A second method of rear delay array combines end-fire topology with polarity reversal, using two subwoofers positioned front to back, the drivers spaced one-quarter wavelength apart, the rear enclosure inverted in polarity and delayed by a few milliseconds for maximum cancellation on stage of the target frequency.
Peak wavelength is at 492 nm and the full width at half maximum | FWHM spectral bandwidth is quite wide at about 85 nm.
For instance, the colour of a dilute solution of copper sulfate is a very light blue ; adding ammonia intensifies the colour and changes the wavelength of maximum absorption ().
A peak of the absorbance curve ( a wavelength where the absorbance reaches a maximum ) is where the rate of change in absorbance with wavelength is smallest.
The commonly quoted parameters for phosphors are the wavelength of emission maximum ( in nanometers, or alternatively color temperature in kelvins for white blends ), the peak width ( in nanometers at 50 % of intensity ), and decay time ( in seconds ).
It can be seen that if such an element is resonant at f < sub > 0 </ sub > to produce such a standing wave pattern, then feeding that element with 3f < sub > 0 </ sub > ( whose wavelength is 1 / 3 that of f < sub > 0 </ sub >) will lead to a standing wave pattern in which the voltage is likewise a minimum at the feed-point ( and the current at a maximum there ).
To achieve the maximum gain, it is necessary that the shape of the dish be accurate within a small fraction of a wavelength, to ensure the waves from different parts of the antenna arrive at the focus in phase.
Applying the above formula to the 25-meter-diameter antennas often used in radio telescope arrays and satellite ground antennas at a wavelength of 21 cm ( 1. 42 GHz, a common radio astronomy frequency ), yields an approximate maximum gain of 140, 000 times or about 50 dBi ( decibels above the isotropic level ).
Theoretically, the maximum resolution, d, that one can obtain with a light microscope has been limited by the wavelength of the photons that are being used to probe the sample, λ and the numerical aperture of the system, NA.
DQDB is rated for a maximum of 160 km before significant signal degradation over fiberoptic cable with an optical wavelength of 1310 nm.
If the source has a maximum overall dimension or aperture width ( D ) that is large compared to the wavelength λ, the far-field region is commonly taken to exist at distances from the source, greater than Fresnel parameter S = D < sup > 2 </ sup >/( 4λ ), S > 1.
Again, this is true only in the far field, defined as: Range = 2 D < sup > 2 </ sup > / λ where D is the maximum linear extent of the optical sources and λ is the wavelength ( Scott ).

wavelength and emission
After Bohr's use of Einstein's explanation of the photoelectric effect to relate energy levels in atoms with the wavelength of emitted light, the connection between the structure of electrons in atoms and the emission and absorption spectra of atoms became an increasingly useful tool in the understanding of electrons in atoms.
Total absorption is measured with normal lamp current, i. e., with a narrow emission line, and background absorption after application of a high-current pulse with the profile of the self-reversed line, which has little emission at the original wavelength, but strong emission on both sides of the analytical line.
Radio observations revealed a sharp increase in continuum emission at a wavelength of 21 cm after the largest impacts, which peaked at 120 % of the normal emission from the planet.
is the wavelength of the electromagnetic radiation ( photon ) when measured at the source of emission.
However, when the absorbed electromagnetic radiation is intense, it is possible for one electron to absorb two photons ; this two-photon absorption can lead to emission of radiation having a shorter wavelength than the absorbed radiation.
The light generated by stimulated emission is very similar to the input signal in terms of wavelength, phase, and polarization.
Since fluorescence emission differs in wavelength ( color ) from the excitation light, an ideal fluorescent image shows only the structure of interest that was labeled with the fluorescent dye.
A star's energy emission as a function of wavelength is influenced by both its temperature and composition.
In a flame test, potassium and its compounds emit a lilac color with a peak emission wavelength of 766. 5 nm ( see movie below ).
* Redshift, the increase of wavelength of detected electromagnetic radiation with respect to the original wavelength of the emission
* 21 cm = 2. 1 dm – wavelength of the 1. 4 GHz hydrogen emission line, a hyperfine transition of the hydrogen atom
The pump laser excites ions into a higher energy from where they can decay via stimulated emission of a photon at the signal wavelength back to a lower energy level.
The amount ionized is small enough for the bubble to remain transparent, allowing volume emission ; surface emission would produce more intense light of longer duration, dependent on wavelength, contradicting experimental results.
From the observed X-ray spectrum, combined with spectral emission results for other wavelength ranges, an astronomical model addressing the likely source of X-ray emission can be constructed.
From this general law, it follows that there is an inverse relationship between the wavelength of the peak of the emission of a black body and its temperature when expressed as a function of wavelength, and this less powerful consequence is often also called Wien's displacement law in many textbooks.
* Light from the Sun: The effective temperature of the Sun is 5778 K. Using Wien's law, it is often concluded that this corresponds to a peak emission at a wavelength of 2. 90 million nm K / 5778 K = 502 nm.
In fact, Wien's law says that the Sun's peak emission per unit wavelength is at 502 nm.
When the spectrum is reckoned per frequency interval, the Sun's peak emission appears at a frequency of 3. 43 x 10 < sup > 14 </ sup > Hz ; this means that the peak emission per unit frequency is at 3. 43 x 10 < sup > 14 </ sup > Hz, which corresponds to a wavelength of 883 nm and is well into the infrared.

wavelength and is
The video signal is amplified and then switched, in synchronism with the three ultraviolet light sources which are sequenced by the rotating mirror so that during one-twentieth of a second only one wavelength, corresponding to red, green, or blue, is seen.
With de Broglie's suggestion of the existence of electron matter waves in 1924, and for a short time before the full 1926 Schrödinger equation treatment of hydrogen like atom, a Bohr electron " wavelength " could be seen to be a function of its momentum, and thus a Bohr orbiting electron was seen to orbit in a circle at a multiple of its half-wavelength ( this historically incorrect Bohr model is still occasionally taught to students ).
In our current understanding of physics, the Bohr model is called a semi-classical model because of its quantization of angular momentum, not primarily because of its relationship with electron wavelength, which appeared in hindsight a dozen years after the Bohr model was proposed.
it was noted by Bohr that the existence of any sort of wave packet implies uncertainty in the wave frequency and wavelength, since a spread of frequencies is needed to create the packet itself.
In states where a quantum mechanical particle is bound, it must be localized as a wave packet, and the existence of the packet and its minimum size implies a spread and minimal value in particle wavelength, and thus also momentum and energy.
It's noteworthy that this record's peak emittance black-body wavelength of 6, 400 kilometers is roughly the radius of Earth.
In physics and optics, the Abbe number, also known as the V-number or constringence of a transparent material, is a measure of the material's dispersion ( variation of refractive index with wavelength ) in relation to the refractive index, with high values of V indicating low dispersion ( low chromatic aberration ).
This amount of energy, i. e., wavelength, is specific to a particular electron transition in a particular element.
In general, each wavelength corresponds to only one element, and the width of an absorption line is only of the order of a few picometers ( pm ), which gives the technique its elemental selectivity.
The radiation intensity emitted by these lamps is decreasing significantly with increasing wavelength, so that they can be only used in the wavelength range between 190 and about 320 nm.
In addition it is necessary that the lamp emits radiation of intensity at least an order of magnitude above that of a typical HCL over the entire wavelength range from 190 nm to 900 nm.
One of these corrections is that for lamp flicker noise, which is independent of wavelength, resulting in measurements with very low noise level ; other corrections are those for background absorption, as will be discussed later.
Another problem is that background is not measured at the same wavelength as total absorption, making the technique unsuitable for correcting structured background.
The frequency chosen is in the visible spectrum near green, corresponding to a wavelength of about 555 nanometers.
The luminous intensity for light of a particular wavelength λ is given by
If more than one wavelength is present ( as is usually the case ), one must sum or integrate over the spectrum of wavelengths present to get the total luminous intensity.
A CD is read by focusing a 780 nm wavelength ( near infrared ) semiconductor laser through the bottom of the polycarbonate layer.
The photons that existed at the time of photon decoupling have been propagating ever since, though growing fainter and less energetic, since the expansion of space causes their wavelength to increase over time ( and wavelength is inversely proportional to energy according to Planck's relation ).

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