Intro

Today, power is transmitted over copper in most High Energy Physics (HEP) experiments. This is a classical and well understood solution; however, it has many limitations. First, copper is sensitive to electric and magnetic fields, which are present in future colliders and liquid noble Time Projection Chambers (TPCs). In colliders, this translates into Lorentz force exerted on the powering cables in a power pulsed system. Until now, the optical instrumentation in TPCs has been located at the anode plane or outside the TPC to prevent a HV ground return within the electric field. Accommodating light sensors reduces the charge-readout coverage and active volume. Power over Fiber (PoF) would enable optical instrumentation within the TPC, maximizing charge-readout coverage and active volume. Optical readout inside the TPC provides a local trigger; improving trigger efficiencies. Maximizing active volume is vital for any statistics-limited experiment.
 PoF completely solves the above-mentioned problems. In such a system, the power is carried by a laser source through optical fibers, which are insensitive to electric and magnetic fields. An optical power converter (receiver) is placed near the sensor (ASIC, SiPM, …). In addition, ground loops are eliminated, thus reducing the total system noise floor. Moreover, we have a material budget gain, as we replace thick copper cables with thin optical fibers. This is of particular interest for e+e- colliders.

The present project proposes to study the feasibility of PoF in extreme conditions, using commercial components. In the first phase, we will set up a lab space with the necessary engineering controls to lower the safety classification of the required class 4 laser to a class 1. Then the receiver will be characterized at cryogenic temperatures (down to 77 K). By adding a power storage capacitor and an LDO regulator, this setup can be used to power an ASIC with a power-pulsing scheme, or a low-power digital SiPM. We will collaborate with universities for the aforementioned. Finally, we will work with national and international collaborators, and will investigate the possibility of characterizing the photodiode with respect to different irradiation doses compatible with e+e- colliders (> 100 krad).

Specifications - Laser

Specifications - System

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