Summer 2023 in the lab

 Some highlights from the lab this summer. We had a crew of three high school interns: Vincent, Maya, and Sam. Vincent was exploring ice sliding on different rock types. Maya used active acoustics to characterize two ice interfaces at different normal stress. Sam used bench top test of carbon mineralization while looking at the effect of stress and pH. They were a great crew!

During this summer we also had a visitor from New Zealand, Lucy, who brought with her some samples from Dave Prior's lab. Lucy was here to learn about attenuation and Hatsuki's new apparatus. We decided to hold a mini-workshop about Q and invited folks from nearby U.Penn.

I can't remember why it was that Travis brought his dewar, but I realized that between his, Lucy's and ours (which Kris was loading up and getting ready to take to the UK), we had an outright gaggle of dewars.

Introducing "PinQ": our new cryogenic forced oscillation apparatus

 With our funding of a study on the dislocation and strain dependence of attenuation (also called inverse Q) and the arrival of Dr. Hatsuki Yamauchi to work on the project, we decided to assess our machine capabilities. It became quite clear that our original idea of using the biax would not be a good idea because it is not stiff enough (which is part of why it is a great friction apparatus). So we needed to create a new apparatus. Yamauchi-san and I had both worked on a great apparatus in Japan, that had high strain resolution and very precise application of stress. That apparatus ran at room temperature or slightly higher temperatures. So we needed to adapt that design (the "TKY-style" apparatus) for cold temperature work. 

2021 and 2022 were bad times for purchasing parts and it seemed every component was on back order and seriously delayed. The machinist also had a back log. Whatever could be done by us, we did.

First big task was to find a nice stiff, hopefully pre-existing, frame. Ted found one (as he does) but it was looking very dirty and not the right color at all. Hatsuki suggested a paint job and new color scheme. And thus the frame was painted a bright beautiful shade of pink.

Eventually the laser displacements meters (and their stage motors), the screw jack, the stepper motor, the piezo-electric actuator and the rotational base all arrived and Hatsuki assembled it all on the stone table Ted had acquired from somewhere.

Copper coils connected to circulating fluid created the cryostat, with a bellows at the top to prevent condensation but not affect the sample testing. The only thing that it needed now was a brain.

This is when we scheduled John Leeman of Leeman Geophysical to come out. Over the course of a few day visit he got us all set up with a LabView control system that would drive the multi-day experiments, monitor temperatures and all other feedbacks, and record the calibrated data.

We then installed a shelf to hold all the control boxes, etc. Here is the resulting set up.

In the Review of Scientific Instruments paper that followed, Dr. Yamauchi provided all of the error corrections and calibrations and describes the working range of the apparatus. Many exciting papers to follow!

 

Tether testing with Vishaal

As part of our NASA-funded STI project, Vishaal came back out again for another few months in the lab. Covid prevented him from coming in the summer, but he was able to spend the fall with us. After successful runs at relatively warm temperature last summer, we were ready to start going colder.  Or so we thought...  

Upon closer inspection we realized the pump in our custom circulating fluid chiller was leaking. After taking it completely apart (a pretty big feat in itself) we found that some seals were cracked and a spring broken. A bit of delay, but hey, now we know how to replace a seal on a pump. Always good to acquire some real world skills.

While we were at it, we decided to do some reorganization so that the chiller flow control valves were attached to the back wall and not hanging off the front of the rig. RTDs were installed to monitor temperature along the fluid path.

We also worked with colleagues at WHOI on a die that allows pretensioning of the tether before freezing the ice around it. Our addition was to add tubing and valves to pull a vacuum on ice samples and flood from the bottom. The final sample assembly is one long bar that fits into the cryostat. The notched square tube allows us to load the assembly without touching the ice. 

An optical meter measures signal loss during shearing of the tethers. Vishaal splices the ends of the tether. 

Here is the whole set up in the new lab. Ain't it pretty?

During Vishaal's last week we decided to push the envelope and go all the way down to Europa surface temperatures (~100K). For this, we took the chiller out of the system and instead went to directly pumping liquid nitrogen into the cryostat. First we pre-chilled by pouring LN all over everything.

Ideally we pump only enough LN to cool the cryostat and it comes out as a gas. But occasionally the LN just poured right through....

It was frosty in there!!  But we held 100K steady for the whole test. A great end to a successful series of experiments! 

 

Final Install on the AutoLab

 This week the guys from New England Research (NER) came out to do the final install on our AutoLab2000 HPHT. The biggest task was to get that big pressure cell, which has been sitting in a big crate in the middle of the prep room for a few months, into the rig. 

Not an easy feat. They decided to use the multi-ton overhead crane in the main lab. Eyebolts on the top of the pressure cell made it easy to lift.

Cell removed, then the frame was brought out to it. 

Then Jake received training and we were good to go.

The lab is really coming together!

It moved!

A lot has progressed in the lab since we first started ramping back up in early July. One major development is that we moved the ice rig. Step one was to disconnect all of the wiring and hydraulics from the frame.

Then Tony and Tom from traffic came over to load both parts onto a pallet.

Meanwhile, Jake and Ted were back in the new lab, prepping the anti-vibration table, making sure it was perfectly horizontal and up against the back wall.

When the table was all prepped, Tony used the jack to put the rig on the table. They found out the hard way in the old lab that it is too heavy to lift by hand - it doesn't look like much, but those steel and aluminum plates add up.

All of this moving was timed just right, because the next day, Steve from the RG group was coming out to install the rig's dedicated Hydraulic Power Unit (HPU). It, and the other two HPUs for the lab, sit in a metal shed just on the other side of the wall behind the rig.

With only 1200 hp, this baby is so quiet. When you turn it on remotely in the lab, you have to touch the line and feel the mild vibration to be sure it's even running. But the bright green "ON" light is also a good indicator.  After Steve left I did some cosmetic work, tidying up all the wires and placed a 1/8" plastic cover cut to fit  the table so that dust and hydraulic fuel don't gum up the 1/4-20 holes all over the table. Ain't it pretty?

Next week Vishaal arrives to start his research, so we'll go through some drills and calibrations and get the cryostat up and running. 

New Walk In

Before the lockdown, we were *this close* to getting our own walk in freezer set up. It will also be housed in the Instruments building, so no more walking across campus in the rain with samples.  A room in the back corner of the warehouse was cleared out and the floor given a nice paint job. That's gray with specks of different shades of blue. We taped off the location for the walk in and awaited its arrival from culinary depot. It arrived stacked nicely on a pallet and the refrigeration team went ahead with installation. 

I walked away late morning to attend a meeting and by the time I returned it was already assembled. They were so fast!

Meanwhile, they cleared a space in the back for the refrigeration unit.

And here it is! The electrical work has been completed. We're just waiting to return to campus to plug it in and start getting cold.

Then we can move over our microscope, microtome, and gear so we can start making samples and imaging them.

Extreme makeover gets even more extreme: Part 2, the prep room

 Here is the room that is attached to our rig room. When you enter, it feels like you've gone back in time, or you've entered a museum dedicated to machine shops of yore... and I absolutely fell in love with it from the first time I saw it.

That garage door opens up to an open outdoor space. I imagine hanging twinkling lights on the open door and having barbecues on Thursday afternoons, cold beers sitting in a bucket of ice...

Nobody needs that many giant cutters, but don't they look cool displayed on the wall? The one-ton overhead crane runs the length of the lab.

The welding station could be a movie set piece. 

But although I told them "Don't you dare paint the walls or floor or take that crane out..." we do need some improvements to be made. We were still midstream on many of these when we got the order to stop work at Lamont, but I will share what's been done so far.

First task was to break down everything metal, clean it, sand it and paint it black.  Starting to look good.

Got my hands on someone's wood countertop that they decided not to put in their kitchen. Mike reinforced the bottom so it wouldn't bow and we put it up on painted black legs.

And finally transferring all of the pressure fittings and gear from the old lab to the new lab, including labeling the drawers. Getting there. When we get back in, we'll put up a big industrial clock and some unistrut shelves on the back wall. Oh, I can't wait to get back in there!