Sains Malaysiana 44(5)(2015): 761–764

Determination of Fano Factor and Pre-amplifier Noise from the Measurement of Energy Resolution of a HPGe Detector

(Penentuan Faktor Fano dan Hingar Pra-penguat melalui Pengukuran Resolusi Tenaga Pengesan HPGe)

S. B. SAMAT* & W. PRIHARTI

School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

Diserahkan: 11 Disember 2014/Diterima: 28 Disember 2014

ABSTRACT

A HPGe detector and γ-ray multinuclide standard solution were used to get several data pairs of photon energy E and detector's energy resolution FWHM. A series of graph of FWHM² versus E was plotted to determine the detector's Fano factor and pre-amplifier noise, which yielded the mean values of 0.123±0.003 and (7.448±0.011) × 10⁻¹ keV, respectively. The Fano factor value agrees within 95% confident interval with the mostly quoted value of 0.13 for semiconductor detectors. The obtained preamplifier noise is in agreement with typical manufacturer's specification.

Keywords: Fano factor; FWHM; gamma-ray spectrometry; pre-amplifier noise

ABSTRAK

Satu pengesan HPGe dan cecair multinuklid piawai sinar-γ telah digunakan bagi mendapatkan beberapa pasangan data tenaga foton E dan resolusi tenaga pengesan FWHM. Satu siri graf FWHM2 melawan E telah diplotkan bagi menentukan nilai faktor Fano dan hingar pra-penguat bagi pengesan, yang memperoleh nilai purata masing-masing 0.123±0.003 dan (7.448±0.011) × 10⁻¹ keV. Nilai faktor Fano ini bersetuju (pada sela keyakinan 95%) dengan nilai yang kerap dilaporkan bagi pengesan semikonduktor iaitu 0.13. Nilai hingar pra-penguat yang diperolehi sama dengan spesifikasi pembekal.

Kata kunci: Faktor Fano; FWHM; spektrometer sinar gama; hingar pra-penguat

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*Pengarang untuk surat-menyurat; email: sbsamat@ukm.edu.my