Introduction

Welcome to the home page for the XRF Core Scanning lab at IODP! This site is designed to provide you with all the information you need to get acquainted with the lab, get started using the instruments, and get familiar with how to process and interpret the data. For additional information on the Gulf Coast Repository, visit: Gulf Coast Repository This site will detail everything about this facility, along with XRF scanning request and cost structures. Please continue reading below, and once you're ready, feel free to start exploring the rest of the content. If you've never been to the lab, or it's been quite a while, I recommend that you start with the visitor's guide. 

About the Lab

The XRF Core Scanner Lab at IODP is part of the Gulf Coast Repository (GCR), located on the campus of Texas A&M University. The lab has been in operation since late 2008, when the first core scanner arrived. 

Renovations of room B140 have been completed, along with the movement of both XRF1 and 2 back into this lab space.

Currently, the lab houses two Avaatech XRF Core Scanners (Figures 1 & 2). The scanners can accommodate split section halves, discrete samples (loaded into holders), rock slabs, and many other forms of material if the instruments are configured properly. The only requirements for good sample analyses are: (1) the material surface must be relatively flat, (2) the material must be able to fit inside the machine (there are height, width, and length limits), and (3) the material must be able to be held firmly in place during the analyses. If you wish to analyze materials other than standard core section-halves, please contact us to determine whether we can configure the instrument accordingly.

In addition to the two core scanners, the lab houses a section-half image logger (SHIL) for collecting high-resolution, section-length images and RGB profiles (Figure 2).

Analytical Capabilities

The XRF Core Scanners are each capable of generating up to 50 kVp of accelerating voltage and up to 2 mA of current. In theory, we can measure any element that has an absorption edge (K or L shell) less than 50 keV. In practice, we can't measure elements lighter than Mg (Z=12) due to strong material absorption, and we can only measure elements heavier than Ce (Z=58) if they are present in very high concentrations (so we can observe L-lines).

Many other elements are difficult to detect due to strong peak interference. Chlorine, for example, is difficult to measure using our instruments because the Cl K-peak significantly overlaps with the Rh L-peaks. Other elements are difficult to measure due to overlaps with characteristic peaks of more abundant elements and overlaps with spectral artifacts. If you're interested in measuring specific elements, please talk to the Lab Manger.

Also, please visit our full analytical capabilities page to learn more about the elements that we can measure, the excitation conditions that we can use, and the time required for the analyses.

Scheduling Time

If you're interested in scheduling time on one or both of the XRF Core Scanners, please contact the GCR curator (info below). The machines are heavily utilized for both Expedition-related measurements and personal scientific measurements. Due to the strong demand, you will typically need to reserve time several months in advance.

Once finalized, please submit a XRF scanning request through SDRM, our sample request site. We will need your scanning conditions, wanted core sections, and a brief research objective.

*If you are planning to scan older cores, we encourage you to contact us first to check the cores for scannability. Older cores can dry out significantly, creating cracks and features that make scanning difficult to impossible. 

Cost

An updated cost structure for GCR analytical services can be found here: Gulf Coast Repository • Core Laboratories and Curatorial Services, under the laboratory user fees. Please contact us through email for further information. This cost covers consumables, instrument wear and tear, and basic staff support. Users are expected to do sample preparation and scanning themselves. The GCR does not currently offer scanning as a service.  There is no charge to use the section-half image logger (SHIL).

Lab Contact

Jesse Yeon

XRF Lab Manager 

International Ocean Discovery Program (IODP) of the Gulf Coast Repository

Texas A&M University

yeon@iodp.tamu.edu

Dr. Michelle Penkrot

GCR Curator

International Ocean Discovery Program (IODP) of the Gulf Coast Repository

Texas A&M University

penkrot@iodp.tamu.edu or curator@iodp.tamu.edu 

More Information

Now that you have a basic familiarity with the lab, check out the visitor's guide and the analytical capabilities page. These will help you plan your visit and your data acquisition program.

Next, I recommend you check out some of our basic lab usage guides, such as the quick start guide, the data processing guide, and the film change guide. You'll likely want to refer to these guides periodically during the initial part of your visit (and they'll be available in hard-copy), but by reading through them in advance, you can familiarize yourself with some of the software and workflows that you'll encounter.

For those who have used the instruments before, and perhaps consider themselves super-users, we have some advanced usage guides. These guides cover:

• Setting up the instrument

• Basic troubleshooting

• Maintenance checklists

Finally, we've included material dedicated to helping you better understand your data. This is arguably one of the most important topics for users of the XRF Scanners, and it is an expansive, highly technical subject. We'll talk a bit about:

•  How to build models to process your data

• How to perform basic quality assurance

Review of important websites to explore:

• General GCR Facility information: Gulf Coast Repository 

• General GCR cost structure: Gulf Coast Repository • Core Laboratories and Curatorial Services 

• XRF/Sample request: SDRM