An Analytical Model of the Delay Generator for the Triggering of Particle Detectors at CERN LHC

Abstract

This paper presents an analytical model of a tapped shift-register based delay generator, which is currently implemented in the High Momentum Particle Identification Detector (HMPID) at CERN and will be upgraded in the coming years. This work aims to verify whether this delay generator can be optimized to provide a delay range of 525 ns with a resolution of 1 ns. In particular, this paper studies how the clock jitter affects the delay generated and its linearity and predict how the current architecture will perform at a higher frequency of operation. The conclusions drawn via the analytical model, are then verified using both a simulation model and an FPGA implementation of the delay generator.

Particle Swarm Optimization of a Rail-to-Rail Delay Element for Maximum Linearity

“…Malta, Malta jordan-lee.gauci.10@um.edu.mt 2 Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Italy highly complex polynomial model of the circuit. However, in [3] linearity was only achieved for a limited range of…”

“…HMPID is a triggered detector, where data transfer is initiated upon the reception of a trigger signal driving the sample-and-hold circuitry. The charge on the pads should be read at its peak such that an optimal signal-to-noise ratio is obtained [2].…”

On the Design of a Linear Delay Element for the Triggering Module at CERN LHC

“…In the case of variable delay lines, the delay can be tuned by both an analog or a digital mechanism. Delay lines have four important characteristics which determine their performance [1]- [3]:…”

“…This work will aid the design of the trigerring module (better known as the Fan-In/Fan-Out module) to be used by the High Momentum Particle Identification Detector (HMPID) at the CERN Large Hadron Collider (LHC). HMPID is a triggered detector, where the signals on the detector pads are read on receiving a trigger signal from the Central Trigger Processor [3]. Currently, during Run1 and Run2, the HMPID receives the Level 0 (L0) trigger signal, after approximately 1.2 µs, which corresponds exactly to the peaking time of the signal on the pads.…”

“…This means that a new delay generator is required to fine-tune the delay on the trigger. In [3], an improved digital delay generator was proposed as a preliminary solution. However, results have shown the issue of the creation of a random offset in the generated delay profile which is not deterministic [3].…”