XRF core scanner

The XRF facility is located at IODP in the Texas A&M University Research Park (see map).

xrfAnalytical Capability

A third-generation AvaaTech (www.avaatech.com) XRF core scanner is located in the ODASES lab at 1000 Discovery Drive. The scanner provides non-destructive elemental identification from the surface of core section halves (or U-channels).

Range of elements:
Aluminum (Al) through uranium (U).

Sample type
This instrument in designed to measure core section halves or slabs (e.g., "U-channels") with flat surfaces.

  • Length: 30~160 cm
  • Width: 5~13 cm.

Detection Limits for some Elements
Muddy sediment measured at 10kV, no filter, and at 20-second count time (AavaTech User Guide):

  • Al: 0.2%
  • Si: 0.1%
  • P: 0.05%
  • S: 0.05%
  • K: 0.04%
  • Ca: 0.02%
  • Ti: 0.05%
  • Mn: 100 ppm
  • Fe: 45 ppm
  • Sr: 5 ppm
  • Zr: 20 ppm
  • Ba: 40 ppm

Spatial resolution
A dual slit system provides variable spatial resolution with the following ranges:

  • Irradiation sample length: 0.1~10 mm ("downcore" or axis of motion)
  • Irradiation sample width: 2~15 mm ("crosscore")

Spectral resolution

  • Multichannel analyzer, 2048 channels at 20 eV/channel
  • FWHM at 5.9 keV better than 190 eV

Measurement Throughput

  • Throughput depends on the measurement spacing, number of runs at different source energies, and counting times. These parameters are discussed further below.
  • As a rule of thumb, typical sediment analyses projects measure 2 to 8 core section halves per 24-h period.