IEC 62088 pdf download Nuclear instrumentation – Photodiodes for scintillation detectors – Test procedures
1 Scope and object
This International Standard applies to solid-state photodiodes(PD) and solid-state photodiodearrays (PDA) used in scintillation detectors or in Cherenkov detectors.Avalanche photodiodes(APD) are also covered by the test methods recommended in this standard, but they needsome additional specific tests also described in this standard.
Not all tests described in this standard are mandatory, but tests that are used to specifyperformance should be carried out in accordance with the procedures described herein.
The intent of this standard is to establish standard test procedures for photodiodes used inscintillation detectors and to define the parameters which shall be provided by the supplier foreach type of photodiode.
Silicon photodiodes are readily available and widely used in scintillation detection. However,their peak responsivity,around 900 nm, does not match the maximum emission at shorterwavelengths of usual scintillators (Nal(TI)，CsI(TI),BGO,CdwO4，ZnSe(Te)). Research isunder way to develop photodiodes from higher bandgap semiconductors or scintillators withlonger wavelength light emission.
Photodiode scintillation detectors have no internal amplification (except in the case of APDs)and need therefore to be coupled to low noise preamplifiers similar to those used withsemiconductor detectors. The noise of the photodiode/preamplifier combination limits its usein low energy gamma ray and X-ray spectrometry.This noise is dominated by the series noisedue to the capacitance of the PD, which increases with its area,and by the parallel noise dueto the leakage current and the input resistance of the preamplifier. In order to optimize thecombination photodiode/preamplifier, the latter is sometimes integrated with the PD. In such acase,some of the tests described hereinafter may be difficult to perform.
The solid-state photodiodes can also be used as direct ionization semiconductor detectors,but the present standard does not apply to this application which is already covered byIEC 60333.
This standard does not apply to hybrid photodetectors，which are vacuum tubes with aconventional photocathode,an accelerating electric field and a solid state device.
3 Normative references
The following normative documents contain provisions, which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards.