Exp393 XRay Lab Technical Report

Summary

Expedition 393 South Atlantic Transect 2 started June 7th and ended August 9th of 2022, this expedition was a continuation of exp. 390 South Atlantic Transect 1. In this expedition we revisited sites drilled during previous expeditions. Expedition 393 recovered both sediment and hard rock cores from different sites. 

XRD analysis was conducted on the AERIS for both hard rock and sediment cores. Samples taken for ICP where powdered and split for pXRF and XRD analysis as well as ICP. Most of the XRD samples analyzed for hard rock where taken in very small volumes from core veins and ran as slurries in the XRD machine per request of the petrology team. The sediment samples were taken as carb_xrd and shared with the chemistry lab as requested by the sedimentology team. LOI was conducted on the ICP samples and weighed to ~5 grams except for samples of lower volume. The ignited powders from the LOI were then weighed with the flux and used to make the beads for the ICP. 

During the course of this expedition samples from 390 where re-beaded per request of the 390 and 393 science party in order to re-run ICP to get more accurate measurements. Also, 390 samples of XRD were re-run per request of the 393 co-chiefs due to an odd peak that was showing in the analysis because of the sample holders. The samples were re-run in the AERIS instead of the Bruker. A summary of the total samples run for expedition 393 and 390 can be found in the "Totals" section below. 

Totals

Samples Re-Run from 390 

XRD Freight Received

XRD Freight Of going

Instruments

BRANSON 2510 SONIFIER

The Branson Sonifier is working great. No issues where present during this expedition. 

METTLER TOLEDO BALANCE

The Balances are working well. No issues. 

When Preparing the LOI make sure to put samples with high carbonate content or sediments samples in ceramic crucibles. Quartz crucibles can be ruined if samples with high carbonates are put in the furnace ruining the crucible and the LOI in the process. (Jeff Ryan input)

BEADMAKER

No Issues with the beadmaker. 

When making the beads from the ignited powders make sure that there are no clumps of sediment. I noticed that when the flux had clumps of sediment the clumps wouldn't dissolve very well with the flux in the beadmaker resulting in spots on the beads. In order to prevent this try to break up the clumps. After talking with the chemistry technician he had to ground the sample with a mortar and pestle for it to be powdered enough for the beads before weighing with the flux. 

Platinum Crucibles

Platinum crucibles can remain in the acid bath for two hours and then be taken out afterwards. Two hours is enough time for the crucibles to be cleaned and then be used again to make beads if beads are urgent. This input was given to us by Jeff Ryan. 12 hours is okay because of 12 hour shifts, but it is not necessary for the crucibles to be clean.

LABCONCO FREEZE DRYER

The old freeze dryer is being sent back to College Station, since a new one has already been ordered and is being shipped to the boat.

DESICCATOR

The new desiccator was set up in the x-ray lab. The desiccator is working great the drierite has lasted the whole expedition with no need to change. 

AERIS XRD

The AERIS was used to run all XRD samples in this expedition. There where three times during the length of this expedition where a sample would be initiated and an error would come up in the screen prompting the machine to take out the sample and cancel the analysis. The error on the screed would read "Motion Control error on the goniometer Omega axis" (Figure 1).  In order to clear the error you have to turn off and on the machine and try to load the sample again. If this doesn't work just repeat restarting the machine. The error would usually clear after the first restart. However, sometimes it would take two or three.  Other than this issue with the AERIS, I had no further issues. The AERIS worked great and I was running samples daily. Most of the samples run during this expedition where slurries (very low volume samples). The science party said the analysis where good and that the machine was detecting the sample even though it was very little volume. 

Open

I will turn off the AERIS after I am done with the analysis. I refilled the water to have it ready for future scans. 

Uploading samples under the same sample ID

In some of the slurries the scientists sampled they took the sample under the same Text ID, but they wanted two different XRD analysis done for different kinds of sediments. For example,

393-U1583F-8R-1W(11/13) (WHITE VEIN) OTHR11684581

and

393-U1583F-8R-1W(11/13) (GREEN VEIN) OTHR11684581

both samples where the same interval and the same text ID.

In order to upload them under the same text ID they where uploaded separately one was run though the machine and uploaded to MUT, then the other. Afterwards, we just checked the uploaded times and then added the specific comment to the sample AKA, WHITE VEIN and GREEN VEIN in LORE.

Since, the AERIS likes to be kept running maybe we should run the corundum and the SI disk every day to check everything is working properly.

D4 BRUKER XRD

The Bruker XRD was turned off during the beginning and that is how it remained for the remainder of the expedition 393.

We (Heather and I) tried to turn on the Bruker at the beginning of the expedition. However, the main power and the x-rays shut off almost immediately after starting a scan. After the machine shut off the sample would remain inside. We were asked by Bruker to get a status file but we couldn't do it because we cannot get communication between the computer and Bruker D4 after the instrument shuts down. We only tried to run samples twice because the sample is remining inside the instrument when it shuts down and we are concerned that the sample changer (internal) may have a collision and cause more damage to the instrument. For now, when we restart the instrument it "remembers" that there is a sample inside and removes it when initializing the drives. 

After the beginning attempt to get the machine going we decided that it was best to turn it off for the remainder of the expedition until it could be serviced by Bruker during the tie-up in Cape Town.

Both the Bruker D4 Endeavor and the Haskris have remained off during Expedition 393. 

X-PRESS

After using the X-Press remember to always close the side valve after you are done (Figure 2). If you do not close the valve fully the X-Press will start leaking oil and you can see some of he oil residue after cleaning behind the x-press. 

Open

SHATTERBOX

The new shatterbox is working great. I had no issue with the powder coming out of the tungsten holders, just make sure you adjust the handle to the proper height. I removed the "damaged" stickers from the holders because I needed to use some of them for this expedition. One of the holders is being sent back to College Station for repairs because the bottom came off. We think it is due to abrasion with time and use. 

Furnace

The furnace stopped working at the beginning of the expedition. One of the elements stopped working which stopped the circuit, so the furnace wouldn't heat up. The electrician was able to re-circuit the furnace for it to work with only one element which took longer to heat up but it was working well enough to reach the required temperatures. This allowed us to use the furnace for the LOI analysis and ignite the powders during 393. We where doing this only in large batches trying to avoid using the furnace as much as possible to prevent it from breaking permanently. Four new elements where ordered to be replaced during the transit. 

LOI

There was an issue during this expedition with the LOI spreadsheet saved on the XRD lab "personal" computer (the one close to the balances). After doing a computer update the spreadsheet that was open in the computer lost the weights for the LOI and "reverted" to a previous version even though the spreadsheet was saved before my shift was over. The update was done while I wasn't on shift so I couldn't let the MCS know that I had an important spreadsheet open on my computer. The weights for the LOI where lost and I had to re-weigh with only 1 gram instead of 5 because there wasn't enough powder left for a re-weighing of the samples. 

Bruker Tracer 5 Handheld pXRF

The Bruker Tracer 5 Handheld pXRF has been working very well. Several scientists that have been working with the instrument have mentioned that the measurements are very consistent and better than they expected them to be. The instrument was used a lot during this expedition and a lot of standards where mounted some rock standards where also made from rock samples taken from the cores to be run when measuring section halves. All the cables from the pXRF have been labeled accordingly and the instrument is being kept in its box. The laptop was placed in the cupboard in the XRD lab. The mount and all other cables and accessories will be kept in the shipment box to prevent any damages. 

During this expedition they only measured section halves using the mount of the pXRF. Only hard rock pieces that where able to fit inside the box where measured. The scientists didn't feel comfortable holding the gun to measure the longer section pieces. This was because they couldn't keep the gun stable and completely flat to the core with the boat movement, and some of the measurements would be cut short because the gun wouldn't be completely in contact with the core surface and it would stop the measurement to prevent x-ray exposure. 

When the gun was mounted on the stand we taped a piece of 3525 ultralene thin film to protect the gun and prevent any powder from coming in contact with the gun, since the protective plastic the detector has is very sensitive. 

The user guide for the pXRF will be finished during 397T in September.

Exporting data from pXRF

I have already made a guide to export the measurements from the pXRF. The scientists mentioned that the data being exported from the pXRF was in a very messy format, making it hard or "nearly impossible to code". I found a way to export the data neatly using excel and its all in the pXRF exporting data guide (guide which will be part of the pXRF user guide once I am finished). This should also make it easier for us to upload the data later to LIMS once we figure out how we are going to do it. I have also uploaded to LIMS the offset of the measurements they took on the section halves because they requested to see the depths in the hole. In the exporting data guide for the pXRF, which is in our laboratory notebook and I created a link in the Laboratory Manuals under pXRF there is a link on the format I used to upload the depths using spreadsheet uploader. 

Accessing Uservol

In order to access OES from the pXRF computer you need an ethernet cable to connect to the wall. This is not ideal in my opinion since we set up the pXRF in different parts of the lab every expedition and not every place has an ethernet cable available. This was a temporary solution for now since the laptop doesn't have internet because it is a shore computer. However, it should be able to access OES so that we can access Uservol wirelessly in order to transfer the data to the scientists. 

Bruker Instrument Tools app

One issue I encountered while exporting the pXRF data was that the computer wouldn't allow me to access the Bruker Instrument Tools app without an administrator password (Figure 3). The MCS on my shift had to log me into the app for me to be able to export the data into the computer without me having to take out the USB from the gun every time. He later figured out that something happened with the computer profile that it might have been corrupted and that is why the application asked for a password. He resolved this issue by creating a "daq" profile in the computer and that allowed me to access the program with no further issues.