Advanced mercuric iodide detectors for X-ray microanalysis

Journal Article · Thu Jan 01 00:00:00 EST 1987 · Scanning Microsc. Suppl.; (United States)

OSTI ID:5384506

Warburton, W K; Iwanczyk, J S

We first present a brief tutorial on Mercuric Iodide (HgI/sub 2/) detectors and the intimately related topic of near-room temperature ultralow noise preamplifiers. This provides both a physical basis and technological perspective for the topics to follow. We next describe recent advances in HgI/sub 2/ applications to x-ray microanalysis, including a space probe Scanning Electron Microscope (SEM), Synchrotron x-ray detectors, and energy dispersive detector arrays. As a result of this work, individual detectors can now operate stably for long periods in vacuum, detect soft x-rays to the oxygen K edge at 523 eV, or count at rates exceeding 2x10(5)/sec. The detector packages are small, lightweight, and use low power. Preliminary HgI/sub 2/ detector arrays of 10 elements with 500eV resolution have also been constructed and operate stably. Finally, we discuss expected advances in HgI/sub 2/ array technology, including improved resolution, vacuum operation, and the development of soft x-ray transparent encapsulants. Array capabilities include: large active areas, high (parallel) count rate capability and spatial sensitivity. We then consider areas of x-ray microanalysis where the application of such arrays would be advantageous, particularly including elemental microanalysis, via x-ray fluorescence spectroscopy, in both SEMs and in scanning x-ray microscopes. The necessity of high count rate capability as spatial resolution increases is given particular attention in this connection. Finally, we consider the possibility of Extended X-ray Absorption Fine Structure (EXAFS) studies on square micron sized areas, using detector arrays.

• Research Organization: Univ. of Southern California, Marina del Rey (USA)
• OSTI ID: 5384506
• Journal Information: Scanning Microsc. Suppl.; (United States), Vol. 1
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
RADIATION DETECTORS
EVALUATION
USES
ELECTRON MICROPROBE ANALYSIS
MERCURY
REAGENTS
SCANNING ELECTRON MICROSCOPY
SPATIAL RESOLUTION
X RADIATION
X-RAY SPECTROSCOPY
CHEMICAL ANALYSIS
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELEMENTS
IONIZING RADIATIONS
MEASURING INSTRUMENTS
METALS
MICROANALYSIS
MICROSCOPY
RADIATIONS
RESOLUTION
SPECTROSCOPY
440101* - Radiation Instrumentation- General Detectors or Monitors & Radiometric Instruments