PoleCATS

After two weeks of hard work, sleep deprivation, both high stress, relaxing and funny moments, good food, awkward saunas, early launch mornings and friendly teams the launch campaign has sadly come to an end. It has been an intense and rewarding period which we will surely not forget too soon.

The REXUS 13 was launched this morning on a snowy period and now all teams (including PoleCATS) are packing up their experiments. Before departure tomorrow there are still reasons to smile including the campaign party and the infamous team entertainment moments on which we have been working in the last couple of days (updates soon).

As a reminder of the complexity, amount of work and people involved in the REXUS program check the group picture taken of just the people present at the campaign (Credits to REXUS/BEXUS).

We just got back from three days in DLR Bremen, Germany with the other three teams who also have payloads on our rocket, to check the experiments don’t cause problems for each other.

For the first day we checked the experiment over and ran functional and simulation tests on our own.  For the second day, the rocket was assembled and we tried to run each experiment separately.  This seemed to mess up some of our readings and on further investigation our circuit boards had an unintentional grounding to the rocket, meaning we were charging it to -6V.  While the other teams waited, we took our experiment out and investigated and fixed it.  That took almost the entire day, so it wasn’t until Wednesday the simulations were finally run, and they went well for all teams  We left very relieved!

Now the experiments will be transported to Oberpfaffenhofen for bench testing in three weeks time.  We’ll be working on the software development until then.

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Thanks to REXUS for these pictures!

Since we’re a team from all over the country, planning times we can work together can get a bit tricky.  This weekend though, we had visitors from Bath and Cambridge working on the flight board designs and the software.

It was the first time we’d met the newest team member, Lucian, who’s a PhD student at both Cambridge and UCL.  There’s been a lot of progress so far on the designs and quite a bit on the software.

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Yesterday Mikael Inga from SSC visited us at MSSL to carry out our IPR to check we’re on track for integration.

Mikael

Well.. we’re kind of behind in the electronics design, so we need to put in more work on that in the next few weeks, but our design is coming along well, and we were given a pass

Hubert and Polly showing Mikael the prototype circuit boards

Getting the team together at MSSL in our new hoodies and polos

So, a lot more work to do this side of Christmas, for final manufacturing, testing and documentation, but it will be worth it once the experiment’s integrated into the rocket system.

Our CCD, a type of detector that’s usually used for detecting light, X-rays and other photons, is being using to pick up electrons instead for PoleCATS. This will work, because the output signal generated in any silicon detector (like the CCD) is created by any ionising radiation creating electron-hole pairs.

Electrons dancing through silicon (from simulation output)

Electrons are very fiddly particles to detect, because of their low mass. Each time one interacts with a silicon atom, it can change its direction dramatically. The energy might end up distributed between several pixels, as in the simulation output below.

A few electrons interacting with silicon

However, in the PoleCATS energy range, only the most energetic electrons will behave like this. For a low-energy electron, the particle will quickly lose its energy within one pixel. We expect these will show up as single bright pixels in the image, and do as much as we can to ensure they show up above light and thermal noise.

We mentioned a few posts back how we have to work with the other experiments on our rocket to make sure we all get along well and don’t upset their experiments or results.. Well, here are the dangers we have with our experiment, and how if we and the other teams weren’t careful, we could upset the workings of PoleCATS..

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The box that will hold our electronics stack has been manufactured!  The drawings for the heat sink/sensor support are at the workshop, and the hatch drawings are just about ready too.  On the other side, the prototype PCBs are all assembled and under testing and redesign.  At the moment we’re working towards our Integration Progress Review which should be at the beginning of September at MSSL.