Time Trap: A Detector with Picosecond Precision ⚡ экспресс
For future experiments, new-type detectors are needed—resistive avalanche diodes (LGAD) with resistive readout, akin to a high-precision CCD matrix for particles. The previous version with capacitive coupling (AC) achieved a time resolution of 38 ps and spatial resolution of 15 µm with a pixel pitch of 450 µm, but suffered from response non-uniformity. Now a version with direct (DC) coupling has been created; its first batch, designed based on Sentaurus TCAD simulation results, was released in November 2024. This is a step toward uniform ultrafast detectors.
In particle accelerators, where matter is smashed into elementary constituents, detectors need filigree precision. Engineers have built a device that resembles a uniformly stretched drumhead: each particle strike produces an instant and clear signal. This allows them to record time with an accuracy of 38 picoseconds, and coordinates down to 15 micrometers.
Early versions suffered from uneven sensitivity: some areas 'sounded' loud, others barely audible. The culprit was an insulating layer that, like a thick glove, muffled and distorted the signal. The unexpected solution turned out to be simple: the contact was made direct (DC coupling), without an insulating interlayer. So the 'glove' was removed, and the membrane rang out equally pure across its entire surface.
These detectors will become the eyes of next-generation facilities. Scientists will use them to test the Standard Model for cracks, looking for the tiniest deviations. The improved sharpness will help spot rare events and, perhaps, uncover new forces that govern the Universe.
🎯 A picosecond is one trillionth of a second. In 38 picoseconds, light travels about 1.14 centimeters—slightly more than the width of your pinky finger.
🎬 Perhaps one day, a network of such detectors will form the basis of a ‘chronovisor’ that records events with picosecond detail.