Performance Evaluation of the Current Birmingham PEPT Cameras

Abstract

Positron emission particle tracking (PEPT), a powerful technique for studying fluid and granular flows, has been developed at Birmingham over the last 30 years. In PEPT, a “positron camera” is used to detect the pairs of back-to-back photons emitted from positron annihilation. Accurate high-speed tracking of small tracer particles requires a positron camera with high sensitivity and data rate. In this paper, we compare the sensitivity and data rates obtained from the three principal cameras currently used at Birmingham. The recently constructed SuperPEPT and MicroPEPT systems have much higher sensitivity than the longstanding ADAC Forte and can generate data at much higher rates, greatly extending the potential for PEPT studies.

Numerical Modelling and Imaging of Industrial-Scale Particulate Systems: A Review of Contemporary Challenges and Solutions

“…In 2022, an upgraded modular camera system (Parker et al, 2022;Herald et al, 2023) was used to image particle motion within an active fluidised-bed pyrolysis reactor used for the chemical recycling of waste plastics (Ingenia, 2022). In this instance, not only were particles corresponding to the bed material used to image the flow dynamics of the system, radioactively labelled plastic pellets were also used to assess crucial aspects of system performance including the residence time of the particle (i.e.…”

Monte Carlo Model of the Large Modular Array for Positron Emission Particle Tracking

“…These two characteristics are the most important detector characteristics in regard to PEPT experiments because spatial resolution predominately influences the ability to resolve a point-like source and the digitizer model controls the count-rate response curve. Thus, these two characteristics determine the spatial and temporal resolution of a PEPT tracer [7].…”

“…In order to use an evolutionary algorithm, to calibrate a GATE model, there must a metric through which the fitness of candidate solutions to the parameters of the digitizer can be assessed. This is achieved through a cost function, shown in (7), which is the product of the percent differences between the experiment and simulation's total, true, and corrupted count-rate response over a range of source activities, calculated using (8)(9)(10). Using this metric reduces the agreement between the experiment and simulation down to a single value which can be optimised through minimisation of (7).…”

“…To perform a PEPT measurement, equipment must first be moved to a lab and placed in the field-of-view (FOV) of a position-sensitive detector. At the University of Birmingham's Positron Imaging Centre (PIC), detectors like the ADAC Forte and SuperPEPT have been acquired or built specifically for PEPT measurements [7]. The Forte dualheaded positron camera was acquired because the two detector heads can be separated up to between 250 mm and 800 mm, which enables the accommodation of a variety of equipment while optimising detector sensitivity.…”

On the Ability of Positron Emission Particle Tracking (PEPT) to Track Turbulent Flow Paths with Monte Carlo Simulations in GATE

“…Different scanners specialised for PEPT applications have been adapted from their original medical imaging purposes to measure particle behaviour in systems of flow. These include the ADAC Forte [14], Modular [15], MicroPEPT [16], and SuperPEPT [17] cameras at the University of Birmingham, UK, where the PEPT technique was first developed [18], and the Siemens ECAT EXACT3D HR++ camera at PEPT Cape Town at the University of Cape Town, South Africa [19] (see Figure 1; referred to as "HR++" henceforth). Other facilities specialising in PEPT measurements are the University of Tennessee, Knoxville in the US [20] and the University of Bergen in Norway [21].…”