- #1
ChrisVer
Gold Member
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I have some question about RICH detectors (in particular HERA-B RICH) and why are they constructed in such a way...I think all the RICH detectors though use the same construction that "confuses" me.
In their case the particle of some unknown velocity ##\beta## enters the gas of known refractive index ##n## and generates Cherenkov radiation at an angle given by ## \cos \theta_c= \frac{1}{\beta n}## . Knowing the angle and the ##n## we can determine the velocity ##\beta##.
However I don't understand how the spherical and planar mirrors help in determining the ##\theta_c##. (I wouldn't use spherical mirrors). One could say that they are used for focusing the light, but I don't understand why I should focus the light instead of measuring it directly and finding its ring radius instead of the "focused" one.
In their case the particle of some unknown velocity ##\beta## enters the gas of known refractive index ##n## and generates Cherenkov radiation at an angle given by ## \cos \theta_c= \frac{1}{\beta n}## . Knowing the angle and the ##n## we can determine the velocity ##\beta##.
However I don't understand how the spherical and planar mirrors help in determining the ##\theta_c##. (I wouldn't use spherical mirrors). One could say that they are used for focusing the light, but I don't understand why I should focus the light instead of measuring it directly and finding its ring radius instead of the "focused" one.