Exp385 X-ray Technical Report

Owned by Former user (Deleted)
Last updated: Feb 04, 2020 by Former user (Deleted)
7 min read

Mackenzie Schoemann

Summary

Expedition 385 was a high recovery sediment and hard rock expedition. Extensive bulk sediment and clay separation XRD samples were taken in conjunction with discrete pXRF samples. Clay samples were measured as a bulk XRD powder, discrete pXRF sample and the powders were used for clay separations completing a glycol treatment and two heating treatments per sample. Hard rock core sections were also analyzed using pXRF for quick elemental analysis. ICP beads were also prepared for chemistry ICP run to analyze the isotopic composition of the hard rock samples. There was extensive use of the Bruker D4 XRD despite the instillation of the new AERIS Panalytical XRD during port call due to the high volume of XRD samples per site.

 

Bruker service call happened during port call to replace the x-ray tube and complete a full preventative maintenance check on the instrument. During port call, the instillation of the new Malvern Panalytical AERIS benchtop XRD happened. Malvern Panalytical provided a software training and instrument use and care training to available technicians throughout the San Diego port call.

Total Samples

XRD SAMPLES: 264

XRD Tests: 433

ICP: 33

pXRF: 262

XRD

Bruker D4 XRD

During port call, there was a Bruker service representative to complete a full preventative maintenance on the D4 and replace the x-ray tube after it showed 70% decay during expedition 383.

During the transit to the first site, there was water pooling at the bottom of the D4 coming out of the high voltage area. The side panel was removed to find if there was a water leak, we discovered water leaking at the connection port for the water “in” line to the x-ray tube. It was an issue with the placement of the tubbing, after moving and securing the tubing the water leak went away. However, when turning back on the high voltage for the D4 it would not turn on. One of the fuses for the detector controller blew. The fuse was replaced and the D4 turned back on. The set of spare fuses kept in the x-ray lab did not match the fuse specs, printed on the fuse box, for the detector controller. The fuses inside the detector controller were a lower amperage. The ETs had spare fuses so we were able to replace the fuse.

Malvern Panalytical AERIS XRD

During the San Diego port, call the instillation of the new AERIS bench top XRD was completed. After the instillation, a few of the available technicians received software training, preventative maintenance training, and instructions on how to use the instrument. The new XRD software, HighScore and Data Viewer, training took place during the last three days of port call. We also received an updated version of the XRD mineral database, PDF4.

At the start of the expedition, we installed support beams to secure the new benchtop XRD.

Due to the high recovery of expedition 385 and the large number of bulk powder and clay samples for XRD the new instrument was not highly used. There was little time for adequate comparison tests between the two machines and for standard runs on the new instrument.

The new AERIS XRD throws a z-axis error if the instrument is not used for multiple days. The error goes away by pressing continue measurement. If that does not clear the error I found moving the sample, putting the sample back in the holder and pressing continue measurement will clear the error. This error does not happen if you are using the instrument on a regular basis.

At the start of the expedition, the instrument was having communication issues with the computer and not automatically downloading the data into the designated folder. Contacted IT and found that the network had changed. Steve was able to map the network drive, which solved the issue. The AERIS user guide provided by Malvern Panalytical has decent instructions on how to solve this issue if it happens in the future.

A second computer monitor was installed in the x-ray lab after the instillation of the new instrument to help visually when using the new software and running the Bruker XRD.

Two issues occurred with the sample holders with the new XRD. The sample holders used in the Bruker do not work in the AERIS, despite the one sample holder tested during port call. If we use the D4 XRD sample holders in the new instrument, you receive an error saying that there is not sample. The other issue happened with the clay mounts that the Panalytical representative overnighted us in port call. When completing the heating treatment for clay XRD samples the sample holder warped and the disks fell out ruining the samples. We will need to contact Malvern Panalytical to see if they have other clay sample holders or explore other options for future expeditions.

Haskris

During port call, the water “in” line on the Haskris started leaking and the ship’s cool water was all over the floor of the X-ray lab. Found that the leak was due to the tubing coming lose on the valve, it was moved and the hose clamp was tightened. This fixed the first leak. A second leak happened inside the housing of the Haskris. Again, it was a tubing issue. All the hose clamps and tubing was checked to minimize any more leaks from happening during the expedition. No other problems occurred.

At the start of the expedition, the electrical valve actuator on the Haskris was replaced after it failed on expedition 385T.

During port call, the Bruker service technician noticed we had the temperature of the Haskris too low. We changed the temperature of the Haskris to 69°C following his suggestion despite what Bruker said during 379T (JR100) that the Haskris chill water can stay around the 40-degree range. There have not been any issues since raising the temperature on the Haskris.

Freeze Dryer

During 385T it noted that the freeze dyer was unable to fully get down to vacuum. I noticed there was significant amount of sediment on the seal and O-ring for the sample chamber so first took it apart, cleaned all the seals, and applied new grease. This did not fix the issue. A leak check was completed and were unable to find any leaks in the system. After checking for leaks in the system, we decided to change the pump with another pump and this fixed the issue. For future expeditions where the x-ray vacuum pump is in high use, it would be good to make sure to clean the seal and O-ring on the sample chamber to prevent any leaks. In addition, the current O-ring on the sample chamber is beginning to stretch out. After fixing the vacuum issue, the freeze dryer ran without any issues.

Handheld XRF

The pXRF ran without issue. Primarily measured powdered discrete samples also scanned a few hard rock core section halves. At scientist request, I scanned unknown shell and unknown fragments found in the sediment core samples for a quick elemental analysis. Exported the pXRF data in ppm.

ICP

Hard rock ICP samples were collected to measure the isotopic composition of the hard rock cores. The TK-4100 Bead maker was fixed at the start of the expedition after electrical issues during expedition 385T. The capacitor blew during the previous expedition. Once it was fixed and installed back into X-ray lab it ran without any major issues. After first starting the bead maker and making multiple beads a small leak was discovered at the water “in” line. The tubing was not all the way on the valve, this tubing was moved further onto the valve and the hose clamp was tightened, this fixed the leak issue and the machine ran without problems. Due to the timing of the last ICP samples collected, the bead maker was ran during the beginning of the transit to San Diego and ran without any problems. The sea state was very calm at this time.

Hard rock samples were prepared for ICP analysis using the LOI powders. All of the samples and standards first were processed for LOI. The program used for LOI was to increase the temperature at a rate of 3°C per min to a target temperature of 1025°C and hold for four hours. In addition to the ICP analysis, the non-ignited ICP powders were used for TIC and CHNS measurements. Following the methods used during Expedition 376.

Twelve platinum crucibles shipped back during port call to be recasted.

Software

The new XRD software and XRD mineral database was installed on the computer in the X-ray lab and on the computer in the core laboratory where the old XRD software is installed. Due to a limited number of software licenses, we did not install the software in the down stairs computer lab. This did not seem to be an issue with the scientist. A suggestion by the scientist was to install the other license on the second computer in the core lab where the Bruker XRD software is located.

During the expedition, worked with the programmers to determine the file formats for the new AERIS XRD so the data can be uploaded into LIMS using MUT. Near the end of the expedition, it was decided the files uploaded by the machines would be as follows:

RAW: only populated only on Bruker runs

UXD: populated by the new HTML/text format file, for both instruments

PICTURE: populated by the diffractogram image just like now, for both instruments

User Guides

The ICP Hard Rock Preparation user guide was edited. Due to the high and quick recovery of core and number of samples for the x-ray lab the SOP and user guide for the new AERIS XRD was unable to be finished.