Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.
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Transcript of Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.
![Page 1: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/1.jpg)
Update on Simulation Studies of the CEDAR Optics
Helen Heath9th December 2009
![Page 2: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/2.jpg)
Reminder (see N.Brook’s talk from August)
• Use Lau’s CEDAR simulation• provide Cerenkov photons to current quartz
window • -> position(x,y,z) and direction(nx,ny,nz) and
wavelength• Optical path simulation
• Use ROOT and its geometry manager
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![Page 3: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/3.jpg)
Z=646mm
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Z=996mm
![Page 4: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/4.jpg)
Parabaloidal “cones”10mm depth 25mm depth
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![Page 5: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/5.jpg)
Summary of results in August
• 10mm cone • 82-87% photon reach PMT cathode• 68-90% of photons reflected off cone reflect
off PMT window• 25mm cone
• 87-91% photon reach PMT cathode• 29-67% of photons reflected off cone reflect
off PMT window
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![Page 6: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/6.jpg)
Cone v Parabaloid
80.0%
82.0%
84.0%
86.0%
88.0%
90.0%
92.0%
94.0%
600 700 800 900 1000
25mm Conical collectors
25mm Parabaloid Collectors
10mm Short ConicalCollectors
10mm Parabaloid Collectors
Efficiency for photons to reach the PMT cathode v z position
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![Page 7: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/7.jpg)
Efficiency for different cone depths
80.0%
82.0%
84.0%
86.0%
88.0%
90.0%
92.0%
500 700 900 1100
10mm cone
15mm cone
20mm cone
25mm cone
30mm cone
12mm cone
11mm cone
9mm cone
Shown for conical collection cones
Note: there is little increase in efficiency one the cones are above 15mm in length
The parabaloid is similar but the efficiency falls more quickly
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![Page 8: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/8.jpg)
Source of Losses
• Previous simulations assumed losses at surfaces due to • 5nm roughness for mirror• 10nm roughness for cones
• Look at cone roughness
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![Page 9: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/9.jpg)
10nm Roughness
-5.0%
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
35.0%
40.0%
0 5 10 15 20 25 30
Reflection at the mirror
Roughness of cone
Reflection from PMT
escaped
total loss
Photon loss v cone depth z=646
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![Page 10: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/10.jpg)
Escapees10
![Page 11: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/11.jpg)
5nm Roughness
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
35.0%
40.0%
0 5 10 15 20 25 30
Reflection at the mirror
Roughness of cone
Reflection from PMT
escaped
total loss
Photon loss v cone depth z=646
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![Page 12: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/12.jpg)
15nm Roughness
0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
30.00%
35.00%
40.00%
0 5 10 15 20 25 30
Reflection at the mirror
Roughness of cone
Reflection from PMT
escaped
total loss
Photon loss v cone depth z=646
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![Page 13: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/13.jpg)
Summary of Efficiency Studies
• Dominant contributions to the photon loss are• Photons escaping the system for depth<7mm• Reflection from the PMT surface
7mm<depth<~10mm• Beyond 10mm the loss at the cone surface
may become the dominant contribution but it increases slowly above ~15mm
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![Page 14: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/14.jpg)
Photon distributions at PMT
• Nick’s studies observed a double peak in the photon angle at the PMT.
• Confirmed to be photons reflected from the cone and those that enter directly (see next slide)
• Also noted that the distribution across the PMT face is different for these two cases
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![Page 15: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/15.jpg)
10mm cone, photon angle to PMT face. Red photons not reflected from cone, blue photons reflected from cone
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![Page 16: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/16.jpg)
25mm cone, photon angle to PMT face. Red photons not reflected from cone, blue photons reflected from cone
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![Page 17: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/17.jpg)
1725mm cone, photon position at PMT face. Red, photons not reflected from cone, black photons reflected from cone
![Page 18: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/18.jpg)
Efficiencies for photons from Pions
• 25000 photons• 25mm cone
• Efficiency 0.10% for all z
Z 646 696 746 796 846 896 946 996# Arrived at PMT 25 26 25 26 23 26 25 24
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![Page 19: Update on Simulation Studies of the CEDAR Optics Helen Heath 9 th December 2009.](https://reader036.fdocuments.in/reader036/viewer/2022062518/5697bf921a28abf838c8ed25/html5/thumbnails/19.jpg)
Future plans
• To look at the muon halo • Feed in any mechanical design constraints
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