Difference between revisions of "Tagger microscope prototype construction"
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=== R&D into Fiber-Array Fabrication Techniques === | === R&D into Fiber-Array Fabrication Techniques === | ||
| − | [[Image:TaggerFocalPlane_ChannelPlan.png|thumb|555px|Scintillating fiber channels as seen by an on-coming electron. Since only energy tagging is required, the members of the 5-channel columns are summed to produce one signal corresponding to that energy channel. The exceptional columns are marked in red - the signals from their individual fibers will be read out to ascertain focal plane orientation and vertical spread.]] | + | [[Image:TaggerFocalPlane_ChannelPlan.png|thumb|555px|Scintillating fiber channels as seen by an on-coming electron. Since only energy tagging is required, the members of the 5-channel columns are summed to produce one signal corresponding to that energy channel. The exceptional columns are marked in red - the signals from their individual fibers will be read out to ascertain focal plane orientation and vertical spread. Note the segmentation of the 100-energy bin (column) array into 20 fiber modules. This is thought to be a more manageable design, corresponding nicely to the photo-sensor/electronics grouping.]] |
The design concept for the Tagger Microscope calls for a scintillating fiber detector array along the focal plane of the spectrally-analyzed beam of electrons. This is a two-dimensional array of broken up into 2 mm<sup>2</sup> patches (as shown in the adjacent figure) representing the cross-sections of the square scintillating fibers. To avoid placing photo-sensors along the path of the electronics, the scintillation light will be delivered to separately-mounted sensors and electronics via clear fiber waveguides. | The design concept for the Tagger Microscope calls for a scintillating fiber detector array along the focal plane of the spectrally-analyzed beam of electrons. This is a two-dimensional array of broken up into 2 mm<sup>2</sup> patches (as shown in the adjacent figure) representing the cross-sections of the square scintillating fibers. To avoid placing photo-sensors along the path of the electronics, the scintillation light will be delivered to separately-mounted sensors and electronics via clear fiber waveguides. | ||
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A project pertaining to design and prototyping of electronics pertaining to bias, amplification and control of the photo-sensors described above has been conducted by Brendan Krueger, [[User:Senderovich|Igor Senderovich]], and Woody Underwood. Due to the expected variability of performance of these solid-state sensors, the electronics provides for individually selectable bias voltage, controlled amplification over a wide range of light intensities, as well as feedback on key on-board voltages and ambient temperature. Additionally, the summation of signals over scintillator channels vertical in the focal plane is incorporated. | A project pertaining to design and prototyping of electronics pertaining to bias, amplification and control of the photo-sensors described above has been conducted by Brendan Krueger, [[User:Senderovich|Igor Senderovich]], and Woody Underwood. Due to the expected variability of performance of these solid-state sensors, the electronics provides for individually selectable bias voltage, controlled amplification over a wide range of light intensities, as well as feedback on key on-board voltages and ambient temperature. Additionally, the summation of signals over scintillator channels vertical in the focal plane is incorporated. | ||
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| + | === Mechanical Design of the Tagger Microscope === | ||
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| + | :''Main article: [[Tagger Microscope Mechanical Design]]'' | ||
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| + | Mechanical design of the Tagger Microscope has begun. The design is intended to simplify the repetitive components necessary while maximizing the flexibility of the device. In particular, the drastic dependence of the electron crossing angle with energy has been taken account: the device will have the ability for orientation of its fiber modules to match any segment in the useful energy range. | ||
| + | Additionally an internal pulser for testing and a three-point remote-control-adjustable plane for the fiber array are under design. | ||
Revision as of 18:58, 26 August 2008
The design of the Tagger Microscope prototype is currently underway. Below are topics concerning the branches of the work required for its completion and testing in preparation for the construction of the fully instrumented Tagger for Hall D in Jefferson Lab.
Project Branches
R&D into Fiber-Array Fabrication Techniques
The design concept for the Tagger Microscope calls for a scintillating fiber detector array along the focal plane of the spectrally-analyzed beam of electrons. This is a two-dimensional array of broken up into 2 mm2 patches (as shown in the adjacent figure) representing the cross-sections of the square scintillating fibers. To avoid placing photo-sensors along the path of the electronics, the scintillation light will be delivered to separately-mounted sensors and electronics via clear fiber waveguides.
Development of fiber cutting, polishing and gluing techniques to enable the most efficient capture and delivery of scintillation light is being conducted by Carl Nettleton
- Main article: Fiber Array Fabrication Techniques
Scintillation Detection Sensors
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- Main article: Characterizing SiPMs
A search for a solid state photo-sensor satisfying the Tagger requirements has been conducted. The new Silicon Photomultipliers (SiPMs) are thought to fit this application better than the traditional Photo-Multiplier Tubes (PMTs) due to the nice properties of the former, including match of fiber cross section, low bias voltage and other factors. See the main page of this project for this design choice justification as well as detailed performance analysis of tested SiPMs produced by Igor Senderovich and Richard Jones.
Photo-Sensor Bias and Amplification Electronics
- Main article: Design and prototyping of SiPM electronics
A project pertaining to design and prototyping of electronics pertaining to bias, amplification and control of the photo-sensors described above has been conducted by Brendan Krueger, Igor Senderovich, and Woody Underwood. Due to the expected variability of performance of these solid-state sensors, the electronics provides for individually selectable bias voltage, controlled amplification over a wide range of light intensities, as well as feedback on key on-board voltages and ambient temperature. Additionally, the summation of signals over scintillator channels vertical in the focal plane is incorporated.
Mechanical Design of the Tagger Microscope
- Main article: Tagger Microscope Mechanical Design
Mechanical design of the Tagger Microscope has begun. The design is intended to simplify the repetitive components necessary while maximizing the flexibility of the device. In particular, the drastic dependence of the electron crossing angle with energy has been taken account: the device will have the ability for orientation of its fiber modules to match any segment in the useful energy range. Additionally an internal pulser for testing and a three-point remote-control-adjustable plane for the fiber array are under design.