Whew! That was a great trip! The teamwork approach of having one fellow in the cleanroom during an extraction, and others available via conference call has been very workable. This week we pulled out a blank, and a high angle track first found by playingthru. The particle is as yet unnamed.
The blank picokeystone served a couple purposes. First, it acted as a control, and as a test for the new experimental setups. Second, it allowed us another practice shot at pulling picokeystones from the collector without risking a live particle. As you know, pulling particles from the interstellar side is vastly more difficult than it was for the cometary side.
The first blank went well, but I had to babysit it — we had some trouble with the needles getting caught on the corners while cutting. The resulting keystone is a beauty. Here it is:
And likewise, the quarry — i.e. the hole left in the keystone once it was removed.
Beautiful aren’t they?
The needle catching problem is an old issue that we have ameliorated with stiffer needles and an improved corner cutting procedure, but it hasn’t been fully solved, apparently. We had ideas in the queue about how to solve this problem should it arise again, but we hadn’t implemented them because we thought they wouldn’t be needed.
Well, now they are needed. And they are the essence of simplicity. Andrew’s idea from some time ago is that instead of cutting a “U” shape, we will cut criss-cross lines — like this:
This is a great improvement because it means that the needle never turns corners. So we shouldn’t have the problem at all. In addition, I appended the idea that we change the sequence of the cuts to leave the pico portion until last. This would reduce the amount of strain on the aerogel in the vicinity of the track and minimize chances of gremlins getting access to the keystone.
So, while I was at Houston, Dave and Andrew threw together all the ingredients and tried this out on our system in Berkeley — to champion results! We’ll soon be trying this on the flight spare collector (not the real thing) in Houston again, to make sure that it is risk free, and then we’ll move back to the flight collector (real thing) for some particle extractions!
Meanwhile, I went on to cut another high angle track — this one was originally found by playingthru and he hasn’t given it a name yet. So, until we get an official name, this is the playingthru track. And here she is (100X, 200X, 500X):
This track has similar angle to the other tracks, so our best guess is that it is a fragment from the spacecraft solar panel that was splattered into our collector after something impacted the panel. That would be called a secondary particle. However, we also know that in such an impact, there is a chance that a fragment of the impactor may fly into the collector, so until we get to look at it with x-rays in the synchrotron we won’t know for sure whether this is space dust, or Earth dust in space. 🙂 But in the interests of not giving false hope, the chances are, probably, it is solar panel.
And finally, here I am waiving to Big Brother (the security camera):
–Zack