PULSE HEIGHT ANALYZER (PHA) DEVELOPMENT AND ITS APPLICATION

• Main Author: Saputra, Casmika
• Format: Theses
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/32153
• Institution: Institut Teknologi Bandung

Pulse Height Analyzer (PHA) has been widely used to measure gamma radiation, alpha, X-rays, etc. The measurement is also known as a proportional counter and Pulse Amplitude Analyzer. Besides being used for radiation spectrometers, PHA is also used in optical-based particle counters. PHA is used for the measurement of particle size distribution of aerosols both for laboratory and field implementation. The development of PHA is currently more focused on increasing the speed of conversion of analog signals to digital processing. The PHA developed by the researchers included the optimization of analog to digital converter (ADC) rates, compact design and low cost, and digital signal processing optimization. This thesis discusses the PHA device that we have developed. As an application, first PHA is used to calculate the radiation spectrum and the second is the measurement of particle size distribution. For the first application, simulation of the detector pulse output signal ? has been carried out based on experimental data. Furthermore PHA converts the signal into a high pulse distribution and time interval. The result is that the PHA calculation corresponds to the experimental results. As for the second application, the PHA device was tagged with an Optical Particle Counter (OPC) for measuring the distribution of submicron particles. The PHA device that has been developed has a working area at a signal frequency of up to 100 kHz. While the measurement range of the particle diameter is 200 nm - 1 um. Size distribution can be obtained by the PHA system with a minimum measurement interval of 10 s so that the system can be used for real-time measurement of particle size distribution.