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!

Centrifuge at Carleton

Thanks to an internally funded collaborative project with the Engineering department, I get to spend some of my days hanging out at Carleton Lab on CU's main campus. In particular I get to spend time near this beast: a 5 meter-arm, 200 g geotechnical Centrifuge.

In particular, we will be making ice samples in this big steel cylinder that will sit atop a rotating rock base, in order to measure friction and bed evolution as a function of velocity, debris content, and normal stress, which is applied via g force in the centrifuge. The rig that will ride in the cage of the centrifuge was custom made in Taiwan and, after a string of unfortunate events, arrived late last spring. 

I'll write much more about this new rig in months to come. There are a lot of tasks necessary to get it to maintain a low enough temperature to make and keep ice, to measure normal load (at 1 g) and torque, to ultimately measure and control pore pressure in the melt that will form at the interface... Lots to do.

I was wiring up thermocouples the other day and I had a treat. Visiting graduate student Hsiu-Chuan Hsu was running some of his slope collapse experiments in the centrifuge. He loaded up the transparent beads in silicon oil in a very high tech fish tank in the centrifuge cage. Liming closed the very heavy, very thick safety door of the centrifuge room.

Then from the control panel they started cranking up the g.

Look at it go!

It has arrived!!!

There were very exciting happenings in the rock mechanics lab yesterday. Our shipment from NER arrived. Off of an Air-ride truck, straight outa Hanover, came seven large items. 

 Some of them were very large items!

Stripping off the protective plastic you can see the Lexan-housed intensifiers (right) and main unit (left) which houses the electronics.

Also in that main unit, we will install the pressure vessel. Currently that steel vessel and the mounting plate weigh ~1200 lbs. They came in a separate crate. 

Three wood crates came in all. 

Once we took off the tops, we could peer inside. One box contained the main pressure vessel, one the CO2 gas mixing vessel and the final one the computer and miscellaneous supplies.

As soon as we got everything opened up and inspected, the "Traffic" team came over to help us move it all out of the prep room and into the rig room. 

First lining it up with the double doors between labs, then taking it off the wooden shipping pallets.

And then moving each piece into its designated blue-taped space. It is a thing of beauty!

I can't wait to get started on some experiments. Thank you New England Research for building us our custom High P - High T Autolab 2000!  And big shout out to Peter Kelemen for getting the funds to purchase this rig. Now let's mineralize some carbon!!