Kamontip Ploykrachang, Decho Thong-aram, Suvit Punnachaiya and Somchai Baotong

pp. 215 - 219

Abstract

A portable gamma-ray spectrometer based on a Pocket PC has been developed. A 12-bit pipeline analog-to-digital
converter (ADC) associated with an implemented pulse height histogram function on field programmable gate array (FPGA)
operating at 15 MHz is employed for pulse height analysis from built-in pulse amplifier. The system, which interfaces with
the Pocket PC via an enhanced RS-232 serial port under the microcontroller facilitation, is utilized for spectrum acquisition,
display and analysis. The pulse height analysis capability of the system was tested and it was found that the ADC integral
nonlinearity of ±0.45% was obtained with the throughput rate at 160 kcps. The overall system performance was tested using
a PIN photodiode-CsI(Tl) crystal coupled scintillation detector and gamma standard radioactive sources of Cs-137 and
Co-60. Low cost and the compact system size as a result of the implemented logical function are also discussed.

Keywords

• pocket PC
• gamma-ray spectrometer
• FPGA
• pipeline ADC
• pulse height analysis