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XRF Core Scanning Facility

XRF Core Scanner

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

Analytical Capability

A third-generation AvaaTech (www.avaatech.com) XRF core scanner is located in the Geosciences Lab (B140) 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.

Contacts

If you have questions regarding analytical capabilities and/or use of the XRF-scanner facility after reading the "How to Get Access to the Facility" section, email the Facility Manager and copy the Facility Advisor or call one of them.

Facility Manager:

David Houpt
Supervisor of Analytical Systems
IODP/TAMU
979-845-2520
houpt@iodp.tamu.edu

Facility Advisor:

Carlos Alvarez Zarikian
Staff Scientist
IODP/TAMU
979-845-2522
zarikian@iodp.tamu.edu

How to Get Access to the Facility

Availability

The scanner is available for use by interested investigators from within and from outside of TAMU. The amount of time allocated to investigators and the schedule are determined based on a measurement proposal evaluation carried out by XRF Core Scanner Facility faculty and staff.

How to Submit Request for Measurement Time

Interested users need to submit a measurement proposal using the Measurement Request Form. Project documentation can be appended to the form.

The XRF Core Scanner Facility science committee will rate the proposals on a first-come first-serve basis and pass a recommended sequence and total measurement time to the Facility Manager.

Schedule

Measurement projects will be scheduled as early as possible, contingent on ongoing projects. The Facility Manager will communicate with the investigator to finalize the detailed schedule based on recommendations by the XRF Core Scanner Facility science committee. Users are provided with their facility access dates based on mutual agreement and commit to vacate the facility as agreed upon to allow other scheduled investigators to begin their measurements on time. The Facility Manager will assist with logistics arrangements, payment, and training as appropriate.

Facility Maintenance, Supplies, and Training

The Facility Manager is responsible for:

• Safety of operations as well as safety during idle time.

• Readiness of tools and supplies, including special film to cover the sample material, helium, and miscellaneous items.

• Introduction of the facility and the instrument operation to visiting investigators.

First-time facility users must receive training before using the instrument.

Cost to User

Costs to the user for instrument use alone are minimal and are based on a formula that includes the line-meter of sample (film, tapes, etc.) and the hours on the instrument (X-ray tube, helium). Additional (a potentially more substantial) cost may be incurred if the user requests our personnel to carry out the measurements (handle, prepare, load samples and/or manage the data).

We have an hourly rate for internal $15/hour, external $27/hour, and commercial users can contact us for estimate. Total cost is based on a formula that includes hours on the instrument and downtime. For specific costs, please contact David Houpt.

 


 

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