So long, and thanks for all the protons! September 29, 2011Posted by gordonwatts in D0, Fermilab, physics life.
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And there were a lot of protons!
This is a picture of the Cockroft-Walton at Fermilab’s Tevatron. This is where it all starts.
It isn’t that much of an exaggeration to say that my career started here. You are looking through a wire cage at one half of the Cockroft-Walton – the generator creates a very very very large electric field that ionizes Hydrogen gas (two protons and two electrons) by ripping one of the protons off. The gas, now charged, can be accelerated by an electric field. This is how protons start in the Tevatron.
And that is how most of the experimental data that I used for my Ph.D. research , post-doc research, and tenure research started. Basically, my career from graduate student to tenure is based on data from the Tevatron. The Tevatron delivers its last beam this Friday, at 2pm Central time (the 30th).
I’ll miss working at Fermilab. I’ll miss working at DZERO (the most recent Fermilab experiment I’ve been on). I’ll also miss the character of the experiments – CDF and DZERO now seem like such small experiments. Only 500 authors. I feel like I know everyone. It is a community in a way that I’ve not felt at the LHC yet. And I’ll miss directly owning a bit of the experiment – something I joined the LHC too late to do. But most of all I’ll miss the people. True – many of them have made the transition to the LHC – but not all of them. For reasons of travel, or perhaps retirement, these people I’ll probably see a lot less over the next 10 years. And that is too bad.
I’ll remain connected with DZERO for some time to come. I’m helping out with doing some paper reviews and I’m helping out with data preservation – making sure the DZERO data can be accessed long after the experiment has ceased running.
Tevatron. It has been a fantastic run. You have made my career. And I’ve had a wonderful time with the science opportunities you’ve provided.
So long, and thanks for all the (anti-)protons.
16,000 Physics Plots January 12, 2011Posted by gordonwatts in ATLAS, CDF, CMS, computers, D0, DeepTalk, physics life, Pivot Physics Plots.
Google has 20% time. I have Christmas break. If you work at Google you are supposed to have 20% of your time to work on your own little side project rather than the work you are nominally supposed to be doing. Lots of little projects are started this way (I think GMail, for example, started this way).
Each Christmas break I tend to hack on some project that interests me – but is often not directly related to something that I’m working on. Usually by the end of the break the project is useful enough that I can start to get something out of it. I then steadily improve it over the next months as I figure out what I really wanted. Sometimes they never get used again after that initial hacking time (you know: fail often, and fail early). My deeptalk project came out of this, as did my ROOT.NET libraries. I’m not sure others have gotten a lot of use out of these projects, but I certainly have. The one I tackled this year has turned out to be a total disaster. Interesting, but still a disaster. This plot post is about the project I started a year ago. This was a fun one. Check this out:
Each of those little rectangles represents a plot released last year by DZERO, CDF, ATLAS, or CMS (the Tevatron and LHC general purpose collider experiments) as a preliminary result. That huge spike is July – 3600 plots (click to enlarge the image) - is everyone preparing for the ICHEP conference. In all the 4 experiments put out about 6000 preliminary plots last year.
I don’t know about you – but there is no way I can keep up with what the four experiments are doing – let alone the two I’m a member of! That is an awful lot of web pages to check – especially since the experiments, though modern, aren’t modern enough to be using something like an Atom/RSS feed! So my hack project was to write a massive web scraper and a Silverlight front-end to display it. The front-end is based on the Pivot project originally from MSR, which means you can really dig into the data.
For example, I can explode December by clicking on “December”:
and that brings up the two halves of December. Clicking in the same way on the second half of December I can see:
From that it looks like 4 notes were released – so we can organize things by notes that were released:
Note the two funny icons – those allow you to switch between a grid layout of the plots and a histogram layout. And after selecting that we see that it was actually 6 notes:
That left note is title “Z+Jets Inclusive Cross Section” – something I want to see more of, so I can select that to see all the plots at once for that note:
And say I want to look at one plot – I just click on it (or use my mouse scroll wheel) and I see:
I can actually zoom way into the plot if I wish using my mouse scroll wheel (or typical touch-screen gestures, or on the Mac the typical zoom gesture). Note the info-bar that shows up on the right hand side. That includes information about the plot (a caption, for example) as well as a link to the web page where it was pulled from. You can click on that link (see caveat below!) and bring up the web page. Even a link to a PDF note is there if the web scrapper could discover one.
Along the left hand side you’ll see a vertical bar (which I’ve rotated for display purposes here):
You can click on any of the years to get the plots from that year. Recent will give you the last 4 months of plots. Be default, this is where the viewer starts up – seems like a nice compromise between speed and breadth when you want to quickly check what has recently happened. The “FS” button (yeah, I’m not a user-interface guy) is short for “Full Screen”. I definitely recommend viewing this on a large monitor! “BK” and “FW” are like the back and forward buttons on your browser and enable you to undo a selection. The info bar on the left allows you do do some of this if you want too.
Want to play? Go to http://deeptalk.phys.washington.edu/ColliderPlots/… but first read the following. And feel free to leave suggestions! And let me know what you think about the idea behind this (and perhaps a better way to do this).
- Currently works only on Windows and a Mac. Linux will happen when Moonlight supports v4.0 of Silverlight. For Windows and the Mac you will have to have the Silverlight plug-in installed (if you are on Windows you almost certainly already have it).
- This thing needs a good network connection and a good CPU/GPU. There is some heavy graphics lifting that goes on (wait till you see the graphics animations – very cool). I can run it on my netbook, but it isn’t that great. And loading when my DSL line is not doing well can take upwards of a minute (when loading from a decent connection it takes about 10 seconds for the first load).
- You can’t open a link to a physics note or webpage unless you install this so it is running locally. This is a security feature (cross site scripting). The install is lightweight – just right click and select install (control-click on the Mac, if I remember correctly). And I’ve signed it with a certificate, so it won’t get messed up behind your back.
- The data is only as good as its source. Free-form web pages are a mess. I’ve done my best without investing an inordinate amount of time on the project. Keep that in mind when you find some data that makes no sense. Heck, this is open source, so feel free to contribute! Updating happens about once a day. If an experiment removes a plot from their web pages, then it will disappear from here as well at the next update.
- Only public web pages are scanned!!
- The biggest hole is the lack of published papers/plots. This is intentional because I would like to get them from arxiv. But the problem is that my scrapper isn’t intelligent enough when it hits a website – it grabs everything it needs all at once (don’t worry, the second time through it asks only for headers to see if anything has changed). As a result it is bound to set off arxiv’s robot sensor. And the thought of parsing TeX files for captions is just… not appealing. But this is the most obvious big hole that I would like to fix some point soon.
- This depends on public web pages. That means if an experiment changes its web pages or where they are located, all the plots will disappear from the display! I do my best to fix this as soon as I notice it. Fortunately, these are public facing web pages so this doesn’t happen very often!
Ok, now for some fun. Who has the most broken links on their public pages? CDF by a long shot. Who has the pages that are most machine readable? CMS and DZERO. But while they are that, the images have no captions (which makes searching the image database for text words less useful than it should be). ATLAS is a happy medium – their preliminary results are in a nice automatically produced grid that includes captions.
Tevatron Saw the Haiti Earthquake January 19, 2010Posted by gordonwatts in D0, Fermilab, physics, physics life.
What you are looking at there is an ACNET plot. I stare at plots similar to this when I’m on shift all the time. The top two plots – the green and red, are position monitors on the quadruple magnets just outside CDF and D0. They are quite stable until the earthquake. The Tevatron was running when this happened, and you can see in that lower red plot that some protons were knocked out of the ring by the ground shaking.
Note these movements are so small you never would have been able to detect them unaided. However, as my wife put it, “that is one expensive seismograph!” :-)
2009. Ready or not January 2, 2009Posted by gordonwatts in ATLAS, CERN, D0, Fermilab, LHC, politics, science.
We’ve made it through the first day of 2009. I have mixed feelings about this coming year.
- Federal Science Funding Levels. The economy is crashing down around our ears. Business responds quickly (layoffs :() – government is a bit slower. If things followed their natural course of action that would mean science funding, along with everything else, will take yet another hit. However, the incoming Obama administration seems to be committed to spending the USA’s way out of this recession, so in the end funding might not change very much. I am hopeful that hard sciences funding will remain at least stable.
- Federal Science Funding Directions. Climate change is what the Obama administration is focused on. There is a good chance that if you are researching something connected with climate change you may have access to increased funding opportunities. I would expect a funding profile similar to NIH’s funding during its years of increase. I would like to think that funding will spill over into the physical sciences – it should because there are connections between the physical sciences and clean air technologies. All of this is applied scientific research. I hope that the pure research funding gets an increase as well, as an investment in this countries future (particle physics is pure research, of course). I’m feeling neutral here.
- Federal Science. Obama’s science team is just a BLAST of fresh air when compared to the current administration’s. After all, his DOE nominee is a Nobel prize winning experimental physicist. Even if the science advisor isn’t elevated to a cabinet position (PDF), there will be someone in the room that knows a great deal about science, research, and how it is done. Even if there are cuts to science funding, I’m very hopeful there will be intelligent cuts rather that unscientifically motivated cuts. I’m very hopeful in this respect.
- State Universities. The economy in states is depressing. Some states, like my own (Washington) that rely on sales tax are being hit hard and very fast. State universities can’t escape that, obviously, and my university is no exception. Unfortunately, this usually translates to reduced raises, inability to counter offers from outside, reduced support for research, etc. In our own department I wouldn’t be surprised if some people left for other universities that, for whatever reason, were able to make good offers in this awful climate. There is, in fact, already evidence this is happening. The only consolation is most universities are in the same boat, and so most of them are having similar problems. I know less about private universities, but I do know the endowments of many of them are also having difficulty. I’m very downbeat about this: it will be a rough two years at least, I think.
- My Science. When it comes to the Tevatron and the LHC… Well, I see no reason that the Tevatron shouldn’t continue to break records in luminosity (they just broke one earlier this week). And the experiments will continue to be flooded with data. While it is possible for one experiment or the other to have a catastrophic failure, I doubt that will happen. And they should continue to produce papers and science at a furious rate. I also am looking forward to real LHC collision data this year. While I hope it will be at the full 14 TeV, I suspect it is more likely to be at 2 TeV, just a hair above the Tevatron’s luminosity. We’ll hopefully know what the machine scientists think about that sometime in February. I’m really hopeful about this.
- New Years Resolutions. Well, I made only one. That way I have a hope of keeping it: make bread more often. :-) I think there is a chance that I will keep this one. Especially now that I’ve said it publically. :-)
Of course, this should also be a fun year, as noted by the Beacon News:
Frustrated with their failed attempt to destroy the world in 2008, the scientists at Fermilab and their counterparts at Switzerland’s CERN physics lab resolve to perfect their new device, the Large Planet-Sucking Black-Hole-o-Tron.
Here is to another great year of data collection and science at the Tevatron and first collision data at the LHC!
Green is a Relative Thing December 23, 2008Posted by gordonwatts in D0, Fermilab.
I’m ending a series of 3 owl shifts at DZERO right now. The Tevatron, the accelerator at Fermilab, has been going great guns all week. It finally broke today. You know it is bad when the post to Channel 13, the web page that tells you the status of the machine, “Experts working on LRF3; no estimate.” The Linac is busted. That means no data for a while.
Looking at the accelerator’s log book (not accessible from outside fermilab) we found an interesting entry (we means myself and the other 3 people here on shift):
An energy-conservation timeline has been loaded
We called to find out what that means. Mike, from the Main Control Room, told us that is is like putting your car at idle. The Main Injector normally is constantly ramping protons up to 150 GeV energy and slamming them into a target. It does this once about every 2 seconds. With the Linac broken, however, there are no protons to accelerate – so why ramp every 2 seconds. It takes energy to ramp… The effective equivalent of putting your car as idle when you are at a stop light rather than keeping it revving at 4000 RPM’s.
Fermilab uses a lot of power – in 2007 the power consumed was about that required to run 45,000 homes. A lot!! As you can imagine this has impacts both on operating costs and general “greenness” (pollution, etc.). There is a broad effort to reduce power at Fermilab, but this is the first one I have seen in the science program. Very cool.
You might ask – since there is no beam, why run the Linac at all? Why not just shut it off. I will point you to a previous posting of mine:
On Tuesday I decided to shut down my home computer. I’m not sure why I decided to do that – I almost never do. … When I hit the “power” button on the 2.5 year old Dell XPS/200 machine the power light briefly flickered yellow… and that was it.
The accelerator is so large and so complex and there are so many different parts (and computers!) that shutting it down and then turning it on is something that is only done when a very long shutdown is planned. Very long means months. Otherwise things fail and then it takes much longer to get back to doing the science.
For those not familiar with the operation of the Tevatron, the “no estimate” isn’t as bad as it might sound. It just means the experts who have looked at the problem scratched their collective heads and said “Hmmm, I don’t recognize this!”. Usually that means it will take several hours to get things going again. Experiments treat it as an opportunity, actually. The machine has no protons circulating and so we can take special calibrations. Or sometimes we can get access to the detector and fix things.
Tomorrow I jump on a plane and my actual Christmas break starts! Happy holiday’s everyone!
English Language Summaries December 19, 2008Posted by gordonwatts in D0, physics, physics life.
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At least one stub article (essentially an extended abstract) for the paper should be added to either an author’s userspace at Wikipedia (preferred route) or added directly to the main Wikipedia space (be sure to add literature references to avoid speedy deletion). This article will be reviewed alongside the manuscript and may require revision before acceptance. Upon acceptance the former articles can easily be exported to the main Wikipedia space.
Keep in mind that Wikipedia articles are to be targeted at a level that an undergraduate could comprehend. Try to avoid jargon and do provide links to other Wikipedia articles at the first use of specific terms, e.g. [[RNA]]. Also the title of the page should appear in bold at the first use of the text of the article, e.g. "eRNA."
This is fantastic. For a long time here at DZERO we were trying to write English Language Summaries (or Plain English Summaries) of all of our papers. For example, here is one for an old Z+b analysis. These were aimed at people who weren’t particle physicists, but had some real interest in the science – the general interested public. We have mostly given up on this, however (I haven’t followed why). Currently the best summaries of this nature I know about are on a blog – Tomasso’s, specifically (e.g. here and here for recent examples).
But Wikipedia is a great idea! It is an increasingly popular search destination. And it is, supposedly, better organized than a blog. And more permanent. Writing the results up there I think would be a great idea. The only thing thing that this doesn’t address is a central pillar of the power of Wikipedia: inter linking. For these articles to really fit in they have to be linked. And if similar results (for example, measurements by both CDF and DZERO of the same thing) are presented then pages would have to be combined or correctly linked. Perhaps a page a paper and then other pages that discuss the specific pages? The experiments could appoint topical editors (i.e. service work) that maintains all the W/Z results, all the Higgs results, etc. Ok, now this is starting to sound like lots of work!
A neat idea, however!
The D0 Run 2 Detector – 5am shift fun November 28, 2008Posted by gordonwatts in D0.
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I’m on shift at DZERO again. The detector is running amazingly smoothly. We have had one interruption that lasted about 1 second (the system fixed itself). So… I’ve been getting a lot of work done! But sometime around 5am my ability to answer email without making an embarrassing error or run a program without having to try over and over… well, lets just say I give up.
So I’ve been playing with a nice image stitch program I found from MSR: ICE. I took some high resolution pictures of the D0 Run 2 detector’s blueprint and stitched them together at max resolution, and then dumped it into a neat high speed DeepZoom image. Check it out here. Looks best when you full-screen it! [you’ll need Silverlight installed, but you should be prompted if you are missing it automatically].
Parts Not Available? eBay! October 6, 2008Posted by gordonwatts in D0, Fermilab.
The DZERO detector – or at least parts of it – are quite old now. And the goal of the Tevatron is to collect as much data as possible as cheaply as possible. So what do you do when you need a spare part that hasn’t been manufactured in 12 years? You can redesign the system to use a modern part… or you go to eBay. I didn’t realize this, but this is what we do at Fermilab for very old parts. How cool is that!? Smart use of money… which I’m guessing is going to be in very short supply in the near future!
UPDATE: Turns out I misheard. The parts were actually purchased on the grey market – eBay came up when the person was explaining what the grey market was. Sorry about that!
5 fb-1 – thanks, Fermilab! September 29, 2008Posted by gordonwatts in D0, Fermilab.
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Fermilab just reached 5 fb-1 of data delivered to the experiments. When things started in March of 2001 I don’t think I ever expected us to get here – but the recent performance of the Tevatron has been stellar! The DZERO experiment has recorded 4.36 fb-1 of data (I expect CDF is close to that). The 13% dead time is due to downtime on our detector’s part – broken bits and normal trigger dead time.
The current results the Tevatron is releasing are all for 3 fb-1 of data – so we have an additional 2/5ths worth of data to improve everything (like our Higgs).
It is Better When You Are Away August 22, 2008Posted by gordonwatts in D0.
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Last week was the DZERO workshop, as I’ve mentioned. During that time many people from DZERO were 1000’s of miles away from the detector. Many of these people help keep the detector running – fix it when it breaks, etc.
So… how did our detector do? It had a better than average week – smooth running with almost no pauses. I guess it was happy not to have all sorts of people tweaking it? Fortunately, nothing major broke – then there would have been real downtime as people tried to fix it over the phone from Prauge!
I guess DZERO should have more collaboration meetings away from Fermilab!
BTW – this is one reason I like taking owl shifts on DZERO. The detector breaks less often because there aren’t people around to mess with it!