I. Introduction

This guide describes the standard operating procedures for the X-Ray imager (XSCAN). The system is capable of collecting linescan X-radiographs on whole round and section half cores. Furthermore, the source and detector can be rotated around the core material for linescans with different view angles.

Theory of Operation

Users should review the X-Ray Methods and Theory Powerpoint from B. LeVay, 2019 for background on X-Ray radiograph acquisition before operating the system.

Hardware

The IODP X-Ray scanner is composed of a 210W, 160 kV, 1.3 mA constant potential X-Ray source and a linescan detector. The source is a Spellman XRBD 160PN210 Monoblock X-Ray generator with a 0.5 mm focal spot. The beam fan angle is 90 x 12 degrees which is distanced approximately 36 cm from the source. The detector is a Hamamatsu C12300-321 composed of a CCD sensor with a ~22 cm field of view utilizing time-delayed integration (TDI) and a resolution of 48 microns per pixel. (Add the corresponding documentation on Confluence: Hamamatsu manual, Spellman XRB)

Shielding

The shielding consists of several complimentary designs. The primary shield (Figure 1) houses the X-Ray source and detector. It is constructed of 3D-printed ABS plastic with hollow walls that are filled with Tungsten powder. The base of the primary shield (under the detector) is a solid piece of 1-cm thick Tungsten plate to block the primary X-Ray beam.  X-Ray scatter is shielded by 2mm lead equivalent leaded vinyl or leaded acrylic panels on the sides, ends, top and bottom of the logger (Figure 2). The leaded acrylic provides a view of the inside of the logger while it operates. The hatches that allow insertion of core material on either end of the logger are also shielded with solid Tungsten plates.

 Figure 1: Primary shield top and bottom halves, the latter shows the tungsten powder filling and solid tungsten plate used in the first design of the XSCAN.

Figure 2: Leaded acrylic and leaded vinyl shielding panels

Safety Systems

The XSCAN imager has multiple safety systems in place to ensure a user does not operate the system in a radiologically unsafe manner. Never attempt to operate the X-Ray source without the proper shielding in place! The safety subsystems include:

• Colored light status indicators (AKA Patlite tower) (Figure 5)
• X-rays ON amber lights on two corners (Figure 3)
• Shutter position sensors
• Door electronic locks (Figure 6)
• X-ray source interlock
• Emergency Stop Switch (motion and X-ray abort) (Figure 7)
• X-rays auto-off after a user-selectable period

These components are wired into one fail safe system controlled by a National Instruments cRIO-9053 unit.

Figure 3: X-Ray emitting lights (lit=ON) on two corners of the XSCAN

Failsafe Circuitry

In order to generate X-Rays, a series of safety switches and shutter positions must be verified to enable the generation of X-Rays.  Certain switches or sensors are operated electrically, others use pneumatics.

Figure 4 shows the failsafe circuit and the safety switches involved.  All switches must be verified before the software command to generate X-Rays will be performed.

Figure 4: Fail safe circuit schematic. 

Visual Indicators

II. Procedures

III. Uploading Data to LIMS

IV. Appendix

A.1. Health, Safety and Environment

A.2. Maintenance and Troubleshooting

V. Credits

VI. LIMS Component Table

VII. Archived Version

Cleaning tube