Difference between revisions of "Tagger Microscope"

Revision as of 20:42, 7 November 2009

View of the tagger microscope from under the electron beam plane, with chamber walls removed

          Main page: Tagger Microscope Contruction (UConn Wiki)

The Tagger Microscope is a movable, high-resolution hodoscope that counts post- bremsstrahlung electrons corresponding to the photon energy band of interest to the experiment in Hall D. While designed as a general-use device, it has been optimized primarily for use in the GlueX experiment, covering the E_γ range of 8.4-9 GeV (E_e 3-3.6 GeV)

The design of the Tagger Microscope calls for the spectrally-analyzed electron focal plane to be instrumented with a detector array of scintillating fibers with axes oriented toward the oncoming electrons. This is done to maintain fine focal plane segmentation in two dimensions:

• fine segmentation along the direction of electrons spread mitigates the rate and increases the energy resolution
• segmentation in the y-directions allows selective readout to match the photon collimator acceptance.

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.

Alignment of the scintillating fibers with respect to the electron trajectories. The mounting rails for the scintillators has been designed with degrees of freedom necessary for online-alignment to the electron plane as well as selection of the active fiber row/

Rendering of the silicon photomultiplier-based scintillating fiber readout electronics.