302
R. Forty and O. Ullaland
Detector
radius
R D
Mirror
radius
R M
m
q
β
ΘD
Cherenkov
radiating
media
Interaction
point
(a)
0.00
0.20
0.40
0.60
0.80
1.00
5
6
7
8
9
1 0
1 1
1 2
Photon energy (eV)
Quantum efficiency
150 nm
200
TMAE
C10H24N4
Benzene
C6H6
Ethanol
C2H6O
Acetone
C3H6O
TEA
C6H15N
DMA
C2H7N
TMA
C3H9N
Wave length (nm)
(b)
Fig. 7.17 (a) Ring imaging optics for particles emerging from a target or interaction region
with zero impact parameter. The detected and emitted Cherenkov angles ( D , ,) are equal if
the detector radius is correctly chosen.[45]. (b) The quantum efficiency for some photo sensitive
vapours as function of photon energy. Adapted from [17]
Velocity resolution ∼ 10 −6 − 10 −7 has been achieved [44]. These are very
beautiful detectors, but with a somewhat limited usage as they require a near parallel
beam, offer a limited solid angle and the material budget is not negligible.
7.4.4 Ring Imaging Cherenkov Detectors
The quest to make a ring imaging detector and thereby utilize all the inherent
properties of Cherenkov radiation as described in Sect. 7.4, was long thwarted by
the inability to get a high spatial resolution photon detector which was sensitive to
single photons and compatible with photon absorptions, Fig. 7.8, in the media and
photon transmission through windows, Fig. 7.9b. The breakthrough came in 1977
with the work of J. Séguinot and T. Ypsilantis [45, 46]. See Fig. 7.17a. Their work
during the initial phase was mainly concentrated around MWPC, Chap. 4, and a
photoionizing vapour additive to the chamber gas.
7.4.4.1 Photo Sensitive Vapours
Figure 7.17b shows the quantum efficiency for some photo sensitive vapours.
The work with TEA, 13 Triethylamin C 6 H 15 N, and especially TMAE, 14 Tetrakis(dimethylamino)-ethylene C 10 H 24 N 4 [47, 48], made it possible to work in the
wavelength range from about 200 to 160 nm and thereby use fused silica as
windows.
13 http://webbook.nist.gov/cgi/cbook.cgi?ID=C121448&Units=SI.
14 http://webbook.nist.gov/cgi/cbook.cgi?ID=C996703&Units=SI.
R. Forty and O. Ullaland
Detector
radius
R D
Mirror
radius
R M
m
q
β
ΘD
Cherenkov
radiating
media
Interaction
point
(a)
0.00
0.20
0.40
0.60
0.80
1.00
5
6
7
8
9
1 0
1 1
1 2
Photon energy (eV)
Quantum efficiency
150 nm
200
TMAE
C10H24N4
Benzene
C6H6
Ethanol
C2H6O
Acetone
C3H6O
TEA
C6H15N
DMA
C2H7N
TMA
C3H9N
Wave length (nm)
(b)
Fig. 7.17 (a) Ring imaging optics for particles emerging from a target or interaction region
with zero impact parameter. The detected and emitted Cherenkov angles ( D , ,) are equal if
the detector radius is correctly chosen.[45]. (b) The quantum efficiency for some photo sensitive
vapours as function of photon energy. Adapted from [17]
Velocity resolution ∼ 10 −6 − 10 −7 has been achieved [44]. These are very
beautiful detectors, but with a somewhat limited usage as they require a near parallel
beam, offer a limited solid angle and the material budget is not negligible.
7.4.4 Ring Imaging Cherenkov Detectors
The quest to make a ring imaging detector and thereby utilize all the inherent
properties of Cherenkov radiation as described in Sect. 7.4, was long thwarted by
the inability to get a high spatial resolution photon detector which was sensitive to
single photons and compatible with photon absorptions, Fig. 7.8, in the media and
photon transmission through windows, Fig. 7.9b. The breakthrough came in 1977
with the work of J. Séguinot and T. Ypsilantis [45, 46]. See Fig. 7.17a. Their work
during the initial phase was mainly concentrated around MWPC, Chap. 4, and a
photoionizing vapour additive to the chamber gas.
7.4.4.1 Photo Sensitive Vapours
Figure 7.17b shows the quantum efficiency for some photo sensitive vapours.
The work with TEA, 13 Triethylamin C 6 H 15 N, and especially TMAE, 14 Tetrakis(dimethylamino)-ethylene C 10 H 24 N 4 [47, 48], made it possible to work in the
wavelength range from about 200 to 160 nm and thereby use fused silica as
windows.
13 http://webbook.nist.gov/cgi/cbook.cgi?ID=C121448&Units=SI.
14 http://webbook.nist.gov/cgi/cbook.cgi?ID=C996703&Units=SI.