Difference between revisions 2373249 and 2373313 on enwikiversity

[[Image:Detectors summary 3.png|thumb|right|250px|This tree diagram shows the relationship between types and classification of most common particle detectors. Credit: [[commons:User:Wdcf|Wdcf]].]]
'''Radiation detectors''' provide a signal that is converted to an electric current. The device is designed so that the current provided is proportional to the characteristics of the incident radiation.

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| publisher = INSPEC, IEE
| location= London, UK
| date = 1994
| {{isbn|0-85296-880-9}} }}</ref> The properties that make CdTe superior for the realization of high performance gamma- and x-ray detectors are high atomic number, large bandgap and high electron mobility ~1100&nbsp;cm<sup>2</sup>/V·s, which result in high intrinsic μτ (mobility-lifetime) product and therefore high degree of charge collection and excellent spectral resolution.

The intrinsic carrier concentration 
for HgCdTe is given by <ref name=Schmidt>{{cite journal|last=Schmidt|author2=Hansen|title=Calculation of intrinsic carrier concentration in HgCdTe|journal=Journal of Applied Physics|year=1983|volume=54|doi=10.1063/1.332153 }}</ref>

<math>n_{i}(t,x) = (5.585 - 3.82x + (1.753\cdot 10^{-3})t - 1.364\cdot 10^{-3}t\cdot x)\cdot 10^{14}\cdot E_{g}(t,x)^{0.75}\cdot t^{1.5} \cdot e^{\frac{-E_{g}(t,x)\cdot q}{2\cdot k\cdot t}}</math>

where ''k'' is Boltzmann's constant, ''q'' is the elementary electric charge, ''t'' is the material temperature, ''x'' is the percentage of cadmium concentration, and ''E''<sub>g</sub> is the bandgap given by <ref name=Hansen>{{cite journal|last=Hansen|title=Energy gap versus alloy composition and temperature in HgCdTe|journal=Journal of Applied Physics|year=1982|volume=53|doi=10.1063/1.330018 }}</ref>

{{multiple image
 | footer = Relationship between bandgap and cutoff wavelength
 | image1 = Hgcdte bandgap x t.png
 | caption1 = HgCdTe Bandgap in electron volts ais a function of x composition and temperature. Credit: [[c:user:Chriberg85719|Chriberg85719]].{{tlx|free media}}
 | image2 = Hgcdte cutoff wavelength x t.png
 | caption2 = HgCdTe cutoff wavelength in µm is as function of x composition and temperature. Credit: [[c:user:Chriberg85719|Chriberg85719]].{{tlx|free media}}
}}

<math>E_{g}(t,x) = -0.302 + 1.93\cdot x+(5.35\cdot 10^{-4})\cdot t\cdot (1-2\cdot x)-0.81\cdot x^{2}+0.832\cdot x^{3}</math>

Using the relationship <math>\lambda _{p} = \frac{1.24}{E_{g}}</math>, where λ is in µm and ''E''<sub>g</sub>. is in electron volts, one can also obtain the cutoff wavelength as a function of ''x'' and ''t'':

<math>\lambda _{p} = (-0.244 + 1.556\cdot x + (4.31\cdot 10^{-4})\cdot t\cdot (1-2\cdot x) - 0.65\cdot x^{2} + 0.671\cdot x^{3})^{-1}</math>⏎
⏎
The Auger 1 minority carrier lifetime for intrinsic (undoped) HgCdTe is given by<ref name=Kinch>{{cite journal|last=Kinch|title=Minority Carrier Lifetime in p-HgCdTe|journal=Journal of Electronic Materials|year=2005|volume=34|issue=6|pages=880–884|doi=10.1007/s11664-005-0036-2|s2cid=95289400}}</ref>

<math>\tau _{Auger1}(t,x) = \frac{2.12\cdot 10^{-14}\cdot \sqrt{E_{g}(t,x)}\cdot e^{\frac{q\cdot E_{g}(t,x)}{k\cdot t}}}{FF^{2}\cdot (\frac{k\cdot t}{q})^{1.5}}</math>

where FF is the overlap integral (approximately 0.221).

The Auger 1 minority carrier lifetime for doped HgCdTe is given by <ref name=Redfern>{{cite journal|last=Redfern|title=Diffusion Length Measurements in p-HgCdTe Using Laser Beam Induced Current|journal=Journal of Electronic Materials|year=2001|volume=30|issue=6|pages=696–703|doi=10.1007/BF02665858|s2cid=94762645}}</ref>

<math>\tau _{Auger1_{doped}}(t,x,n) = \frac{2\cdot \tau _{Auger1(t,x)}}{1+(\frac{n}{n_{i}(t,x)})^{2}}</math>

where n is the equilibrium electron concentration.
{{clear}}

==Entities==
{{main|Radiation astronomy/Entities}}
'''Def.''' "the fraction of photoelectric events which end up in the photopeak of the measured energy spectrum"<ref name="Krawczynski">{{cite book
|author=Henric S. Krawczynski
|author2=Ira Jung
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{{tlx|Radiation astronomy resources}}{{Principles of radiation astronomy}}{{Sisterlinks|Radiation detectors}}

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