I even started to work on a post, but was sidetracked a bit by talks (and nice sunny weather).   It has been increasingly difficult for me to post with any regularity.  I am as excited to be working here at the LHC as everyone else, but somehow that energy gets spent on things other than blogging. So this is my last post, I’ve decided not to continue any more.

Since I started we went from a very incomplete system (cables missing, etc.) to one that is an integrated part of CMS.  A lot of hard work, some scrapes and sore muscles, some very long days (and nights)…all for a better Regional Calorimeter Trigger.

The recent delay was a discouraging, but these things happen. The LHC a very complicated system, running in a very new way. I hope that we can use this time to polish our system. 

Thanks to everyone for their interest and comments.  Its been fun!

All the best,

Pam

Science has always been about trying to understand some sort of phenomena.  For high-energy particle physicists it is about exploring the nature of matter, at energies never seen before.  

But the LHC and all its experiments have a human side too, because nothing this size could ever have been built in isolation.  To construct something this large required collaboration on a grand scale, both money and resources:  human and material.  People work together, towards one common goal, with no concern for the other person’s origins or affiliations, since we have a job to get done, in time.

It has been wonderful to meet and work with people whose countries I may never have the chance to visit, and I think it is something people often forget about when they comment in these articles. We have overcome personal prejudices and barriers put up by our own countries to come together and work towards a common goal.  

I am as anxious as the rest to see it work and analyze all the data, but I don’t want to forget all the wonderful people I have had the pleasure to work with.

I am reaching a point now, after working on hardware for nearly 6 years straight, that I have to actually begin to look again at what comes out of it with software tools. The problem is, the tools have changed. Not necessarily for the better, but they have changed, and this dog has a few new tricks to learn.

One of these tools is an analysis and graphing package, that I need to use to turn columns of numbers, for example, into a graph to get something I can look at use to make a decision, for example, on timing. It is called ROOT which I think stands for R(?) Object Oriented Tool or something like that. I don’t really know. I was raised on PAW (Physics Analysis Workstation), another analysis and graphing package, based on FORTRAN, and got my paws wet with that. I spent years working with PAW, and now I have to switch to ROOT. I am basically learning by reading web pages and such, but for awhile today it completely flummoxed me. But finally, I got it, and I have to admit, some things are better, like the C++ like programming. But I still have a long ways to go…

The other I am trying to figure out is our CMSSW (CMS Soft Ware) package. I can now get it to run for me and produce some output that might be useful, but I needed lots of hand-holding to do that. Slowly I am getting it, but I am not yet ready to change the base code. I’ll leave that to the Graduate Students for awhile longer. I’m liable to throw a monkey wrench into the works.

Now I am going to work on a talk with another tool that seems to have changed significantly in its new release, ugh. Thanks Mr. Gates.

We had a lovely April, so I went out and bought a nice outdoor table and chairs, so I could eat and relax on my terrace. I’ve just used it once – the weekend I bought it. Every weekend after that its been too wet or too cool. I finally had to bring the wood table top inside to treat it since it didn’t stay dry long enough to do it outside.

The potted plants, however don’t seem to mind too much, and there is enough sun for them. They keep flowering and growing, so I guess it isn’t as bad as I thought, since they’re happy. But I’m cranky from not being able to go and sit outside in the evening after work.

I’m going to file a complaint with Mother Nature.

This week we spend another short spell running our detector for five days, like I described here. I am grateful I have no shifts (especially the 11pm-7am) and that the whole thing ends on Saturday afternoon. Just in time to join my husband for a two-day late anniversary dinner in downtown Geneva. Three years and counting (though I have known him much longer – since 1996).

So there is more hardware to prepare tomorrow morning and to check out. By the way that stands for Cosmic Run at Zero Tesla. Pronounced Crew-zay, due to the French influence around here.

On top of it all, EURO 2008 (soccer/football) has started. This time it is in Switzerland & Austria. I have never seen so many national flags on display, nor as much energy emanating from a crowd, than I did on Saturday while I was out shopping at a Geneva area mall. So, since I have almost all my paternal-side family in the Netherlands, now I head home to watch them play Italy. If they do well, I might finally buy the orange (eek) jersey for myself. You can see Dutch fans for miles…

At the same arcade, there was a game called Whac-a-Mole. This consisted of little mole heads that popped up and you hit them back down again (with a mallet that looks like a giant marshmallow on a stick). I tried this once or twice, but it was too close to video games for me. I am not great at the hand-eye coordination exercises.

Today we are doing studies with the trigger again. I am using this period of time to check and see if two fixes I made worked. They seem to have worked, but two more popped up! I was just reminded of this game. I take my (soft) mallet and whack the moles down, and then they just pop up again, somewhere else. I hope when the game is done, and the moles are gone, I get enough tickets to redeem them for a really nice prize.

Though there are a few of us dedicated souls here, including Jessica, a Wisconsin graduate student:

I will not think about warm beds, or that my husband and cat are in my warm bed…until later.

P.S. I apologize for the lack of clarity – my cell phone was used to take the pictures.

P.P.S. Just read Monica’s blog, and I now know how I can fill the last few hours: I can write documentation!

The little dramas occur all the time here. While we rarely have any sort of tantrum (though at times I feel like it), sometimes we do stand or sit there wondering what we do now, curse a little, or just sit there, head in hands.

Mostly, these occur because we have forgot some vital step or value to enter, and we cannot figure out why its not working. Though we are getting closer to the 1-click configure, there is still some way to go.

Sometimes we’ve done something stupid. On the computer, I’ve pressed the wrong button and wiped out all my e-mail programs Inbox. Sheepishly, I had to ask our system manager to restore it if he could restore it.  I only lost a few recent ones, luckily, I guess.

Or just plain bad luck. After hours of work, we finally start going, and the cooling fails.  On Wednesday we had a brief, CERN site-wide, power outage. Then on my way to the experiment to turn things back on, I hit a curb with my car, the front tire went flat, so I changed the tire.  After I got there, I found a board that blew its fuses, and spent hours trying to get something to configure, as the program kept crashing (with no useful information), and then I tried power-cycling one of the crates I was using.  After that, it worked.  At 7pm I was finally ready to go home.

A la prochaine

p.s.  Sorry this is late!  Family came to visit and I just lost track.  Next week we have a period of running the detector, so there should be some new and interesting stuff going on!

CERN recently had Good Friday and Easter Monday as lab holidays, so the whole lab quieted down for a four day break. Just before it started, I decided to do a study of the relationship of two clocks used by my system.

In order to capture the data coming on our links from the calorimeters we have one clock at a specific frequency. It has one tick every 8.33 ns (0.00000000833 s), or 1/3 of the LHC machine’s tick of once per 25 ns (every LHC tick is a possible collision). We do this to speed up the rate at which our data is processed on our boards.

Our second clock has one tick every 6.25 ns or every 1/4 of a LHC machine tick. We have a specially designed high-speed chip, called the Phase ASIC (Application Specific Integrated Circuit) which takes the data coming from the links every 8.33 ns and rearranges it to run at the 6.25 ns clock. This way we can process lots of data quickly, in parallel. However, the clocks’ phase has to be good, that is the relative ticks have to be aligned in a certain way. This is pretty delicate and requires careful study.

I spend two evenings, until 10pm, clicking buttons on display to make a study of this relationship. I can’t say it was exciting. It was necessary to take frequent breaks to avoid clicking too soon or missing one…about like watching my paint dry. But at the end I had a nifty plot, which gave me a great idea of where I should set those clocks.

This has to be repeated, but the next time I will automate! I didn’t have the tools then, but I do now, thank goodness. It can even run without me.

A few years ago our first engineer retired, and I had to validate one of the remaining boards (and re-validate the others, as their new-and-improved versions came in from the manufacturers). As much time as the engineer and I spent together and went over things, there were still holes in my knowledge. Tossed into the fire, I had to really begin to understand the schematics, the parts on the boards, and the data flow in gory detail (and ask plenty of stupid questions of the new enginneer). Was this system going to do what it was designed to do? I have done my darndest to make sure, but sometimes I feel like I am missing something. I guess that it is a good thing, but even though, we sometimes overlook the most crucial. I hope that hasn’t happened here, but in the end we are all human.

Happily, I had Friday off, and went to lovely Strasbourg to catch my breath, see the sights, and to have yummy Tarte Flambée (Flammkuche to the German speaking world), a delightfully simple combination of crème fraîche, bacon (lardons), and onions often on a crispy, almost cracker-like crust. With a nice Riesling, pure heaven. One nifty version had no bacon, but real Munster cheese on it. (If you can’t tell, one of the joys I get from traveling is sampling the local specialties.) By the way, Strasbourg is a lovely city. We want to go back and spend some more time exploring the Alsace.

This week, back to frozen pizza.

A la prochain…

For this experiment, it is much more sophisticated. We have a Remote Operations Center (ROC) at Fermi National Accelerator Laboratory (FNAL), all the way across the ocean near Chicago. We also have a control room located at the main CERN site, and one upstairs from where we currently sit, which isn’t quite ready for prime time (it’s lacking vital things, like computers, and a coffee machine). These do/will have fast internet connections, computers, printers, and the like.

But, when we are downstairs, such as during this past week, we were trying to keep things going with some colleagues by phone, which proved difficult. I was playing secretary and answering the fixed phone, and things were only slowly moving forward. People were becoming frustrated. At this point in the commissioning of the experiment, it really helps to be in the same room with the experts involved. The communication channels are always open since they are just a shout away. (Unless one expert is on the phone remotely with someone else, which is unavoidable, since we _almost_ all have mobile phones.) Things are still a bit unstable and unpredictable as we commission the system. Soon it will get better, but it is still a lot of “two steps forward, one step back”.

Here were are – all experts underground:

And I’ve been down here too much this week, and I’m getting bleary-eyed and I am ready to spend some time above ground this weekend – I think my vitamin D stores are low…

A la prochain…

postscript to the previous post: Evie had a little improvement, and we brought her home for a couple of days, but again she deteriorated. We made the tough decision to put her to sleep on Monday, Feb. 4, she was 7. We miss her, of course, but couldn’t watch her suffer anymore. She was a loving, affectionate, fun cat, and we are glad to have been on her staff: “Dogs have owners, cats have staff.” – Unknown

We also use it to keep in touch via e-mail and video conferencing, document our hardware, and research topics. Because of all this, and because I am living abroad, far from my family, I have access at home as well. I have wireless so that I can sit in any room of my small apartment and work, talk with my family via Skype, shop, or just goof off and surf the web. I love this technology for all it enables me to do.

But it sometimes seems to rule my life – my home computer is beeping at me whenever an e-mail comes in – demanding my attention. If I happen to read an email before I go to bed that agitates me in some way, I can’t go to sleep until I answer it. For complete peace, I have to put my computer to sleep too. Sometimes I don’t want to talk to anyone via Skype, so I have to shut that program down, and the mail program has to be shut down too. There are times when the spam is out of hand, and I hate it for all that.

But it was recently able to give me some answers and some peace of mind. My littlest cat, who has even had her picture in one my posts (Evie: see above), has developed a very rare condition of the nervous system, dysautonomia. This condition leaves her digestive system unresponsive because the contractions which are automatic don’t work anymore. Because of the internet, I was able to find out that there is no treatment, other than symptom relief, and it is fatal. This sounds awful, I know, but it allows me to be able to let go, as hard as it is, and not be angry with the vets for not doing enough when they care for her. We are trying something experimental to see if it helps, for the next few days, but don’t want to see her suffer, so at some point we will have to say it is time for her to go.
A la prochain…

When I lived several years ago in Hamburg, Germany, I didn’t need a car. And I wish I could have done the same thing here. There I could get around by public transport or bicycle and not have to worry about insurance, maintenance and repairs. It is a lot cheaper, and if I was in a hurry, I could always take a taxi.

I can’t do that here. I work on 3 different sites at CERN. The experiment is at the red CMS dot on the picture below. Meetings are most often at the main site (next to the red ATLAS dot). CMS is the furthest away from the main CERN site. The other site I visit, Prevessin, is somewhere in between. The LHC ring is 27 km in circumference. In the course of a day, I often have to switch sites. This is a minimum of 8.5 km (I will measure this the next time I do it with my car’s trip computer!). And I take a short cut through the countryside…not the longer truck or bus route! Not that there is a bus.

So some days, when things are not well planned, or something crops up, I make 4 trips. Each one takes about 25 minutes (if I am lucky I make it in 20), unless I get stuck behind a farmer on his or her tractor, or I have to wait for the cows to be moved to the next pasture. Some days, I feel like all I am doing is driving. Those days I have to remind myself what a nice countryside it is, since I am spending about 1.5 hours driving in it, almost always on the same roads, staring at the same cows.

But being the nature loving type, I occasionally get rewarded with a glimpse of something special. Regularly I see grey herons and large birds-of-prey in the fields, an odd fox, and tremendous views of the Alps as I just leave CMS on my way to CERN. Then I am glad I made the drive that day.

A la prochain…

But about work, I have thought of some “resolutions” for the next year:

1. I will not scribble my to-do lists everywhere and then have to sort though a pile of notes to figure out what I noted. I will write them down on the same piece of paper in legible handwriting. I will actually write the critical things in my notebook again. Scraps of paper get lost.
2. I will actually take at least a half hour for lunch and go away from my computer or electronics to give my eyes a break. Even if I just stare at the wall while I eat. Eating in front of your computer risks sticky/crumby keys and orange juice on the screen.
3. I will not send e-mails without checking the TO: field carefully since Mac Mail auto-completes the name, and it isn’t always the right person. So-and-so doesn’t need to hear about the missing cables.
4. I will write documentation with details for my colleagues.
5. I will label things – spare parts, cables, etc. so my colleagues can find them too.
6. I will find time to read about physics and not browse the electronic parts and tools at Farnell.
7. I will work on my French conversation so that I don’t get hung up on because I am taking too long to formulate my sentence on the phone. Not everyone here speaks English!
8. I will try to keep the lab and the cabinet underground neat. I will not dump things on the lab bench.
9. I will remember to turn off the soldering iron/microscope lamp.
10. And lastly, I will not procrastinate the jobs I don’t like. Better to get them done and over with then fret over doing them! The scratches from the cable ties and the banged knuckles heal.

Happy New Year et Bonne Année

Pam

During the GREN we include parts of the CMS detector that are located underground in the data taking stream. This includes the trigger electronics, the system that decides if an interesting event has taken place, and the system that I am most involved with. For the first time since we started these Global Runs (GREJ,GREA, GRES, etc.) my beloved (perhaps that is a bit too personal) Regional Calorimeter Trigger has joined in. And not only one or two crates, as is often the case when we test “slices” from the calorimeters (see previous posts), but the whole thing. Eighteen crates of our electronics receiving bits of data representing energy from the Hadron Calorimeter (HCAL) electronics (which gets its data from the central part of the HCAL) then processing it, and sending out the results to the Global Calorimeter Trigger, which sorts it and forwards the highest energies (including location in the HCAL) to the Global Trigger (GT), who finally combines it to find coincident signals in the top and bottom of the HCAL. (Phew!) If it then it passes the requirements set at the GT, i.e. energy greater than some value and the coincidence, the GT sends out a Level-1 Accept (L1A) to the systems that just sent it. This L1A tells the electronics that that was a good event (it is saved in a memory until told otherwise) and the data is retrieved and sent on to the High-Level Trigger, a computer farm, for processing. There we can refine the tracks in the muon chambers and tracker, the energy deposit in the calorimeters…for later analysis.

Our source of events is cosmic-ray muons (basically heavy electrons) caused by protons and nuclei from space interacting in the atmosphere. The higher energy muons can get through a lot of material relatively unscathed (to our detector underground), and we can use the light they leave in the calorimeter as the pass through as a way of detecting them. It’s exciting to see my system in its final form, working!

Of course, we are not ready yet. Though all the electronics are there, it is still somewhat rough. I still have to get another system into the mix, the electromagnetic calorimeter, who are busy commissioning right now. They have to be timed in with the HCAL. And we are using only one of the two spigots out of the RCT – one still lacks the connections out, and will need intense testing, very soon.

I am pretty happy about it. I will post a picture of one of our triggered events here soon!

One of my colleagues remarked that we were not “On the Critical Path”, which was an opinion I was glad to hear. This was the “little thing” that made my day. However, there is no time to sit back and relax yet!

A la prochain…