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June 30, 2005

Ready for the Next Picnic

Boxes1Vince just came over to my office and helped me to inventory and pack up all of the Jlab Graduate Student Association sports equipment and picnic supplies that had been left over from the last picnic that we held two weeks ago.  This stuff has been all over my office floor since then.  I should have taken a picture of all the stuff while it was strewn all over my floor...it was a real mess.  However, I really wanted to take an inventory and get everything packed up nicely before putting it all back into storage.  The equipment had not been used in a long time before we organized this June picnic, so I had to spend a great deal of time tracking down where it had all been hidden away and forgotten about.  I even had to send another of the officers, Peter, out to buy some Frisbees and a soccer ball since I could not find the GSA ones.  I do not want to go through all of that again! 

It is amazing what you find when you go through stuff like this.  For instance, we discovered that the Jlab GSA has (among other things):

  1. 19 badminton racquets (why 19? what happened to the 20th?  Five of them are a brilliant fuchsia too...) and various bits and pieces of the shuttlecocks
  2. two DVDs about how to play Frisbee properly, as well as a handbook that has diagrams to teach people how to throw Frisbees under their legs and behind their backs...the pictures look vaguely like a martial arts handbook
  3. a solitary tennis ball (but no tennis racquets, and we don't have a tennis court here)
  4. a football tee (but no football, of course)
  5. a couple of weird rubber baseball-like things and a Nerf bat
  6. various other odd and mis-matched pieces of equipment.

Although I am confident that a creative soul could compile all of this into an interesting and unorthodox game, it is clear that we will have to consider acquiring some equipment to round out the collection a bit.  Even so, I am pleased that all of this stuff is no longer all over my office floor.  Now it is all inventoried, boxed, and labeled, ready for storage until the next picnic or activity, which should be sometime in August if I can make the time to plan it.  Happily, it should be a whole lot easier to track this stuff down now!  Thanks Vince!

June 28, 2005

No Rest for the Weary...

It is true that there is no rest for the weary.  I am already working on my next poster!  Today I have started to draft out my poster for the Gordon conference, which takes place in a little less than two weeks.   If I had been clever, I would have submitted the same abstract as I did for the poster competition, so that I could have used the same one!  Oh, well.  I'll make another pretty poster full of interesting stuff.  If I can get my code completely debugged and running well on time, that is...  :)

I need the distraction anyway.  Today is my father's birthday, so it has been a hard day for me.  He passed away unexpectedly a little over a year ago, and I really miss him. 

I am really looking forward to the Gordon conference.  Vince and I will be on our way up to Maine in less than two weeks now!  Vince has never been to New England, so I am looking forward to showing him some tidbits of my lovely home area while we are there.  Who knows what sort of trouble we will get into when we are not attending sessions?  :)

June 27, 2005

Fireflies and Summer Rain

June is the month for fireflies (also called lightning bugs) here in Virginia.  Because of this, I love sitting out on my front step in the darkness of the evenings and watching the flashes of greenish light as the bugs fly around the yard.  There are hundreds and hundreds of them that fly around the little forest around my house.  It is easy for me to understand how stories about faeries and pixies came into being when I watch them.  The forest looks absolutely magical as these glowing creatures flit about, especially in the small grove of tall bamboo that grows in one section of my patch of woods. 

Back at my home in New Hampshire, thousands of these little fireflies congregate in the fields and forests of the old family farm each summer, and are absolutely spectacular to watch each night.  It is as though you are watching a starry night sky, only the stars are constantly in motion.  There is a marshy little wetland full of cattails at one end of one of the fields, and in the evenings as the sun sets in the summertime, a thick mist emerges from around the marsh and rolls across the field, enveloping all the fireflies in a thick and mysterious blanket of mist.  If you are looking out at the field at night, you can see thousands of flashes of light in the mist.  It is absolutely magical, and it feels as though you were watching a faery dance unfolding before your eyes.  Sometimes, you can also catch the movements of the deer on the edge of the woods, which just adds to the enchantment.

This weekend, I attempted to take some pictures of the fireflies around my little cottage, but to no avail.  The automatic point-and-shoot features of the digital camera I am using completely thwarted me.   I am going to take some rather lengthy timed exposures with my beloved Nikon in the next few days if I have the chance, but since that will be on film, and I am somewhat sporadic with getting film developed promptly (I was much better about that when I developed my own), the photographs will not be posted for a while.  So everyone will have just to believe me that the fireflies are amazing around my home right now, especially those of you who who are unfortunate enough to miss out on them since they are very rare in the Western part of the USA.

Blackeyed_susans_1Since I could not manage to capture any frames of the glowing fireflies, I will post some photographs that I took of the summer flowers that are blooming around my home right now.  It rained on Sunday afternoon, and after the shower had passed, I went out and photographed the blooms with the raindrops still on them.  The rain somehow perfectly accents the vibrancy of these summer flowers.  The dazzlingly pink geranium in one of the pictures was given to my by my parents and guards my front step along with a potted English ivy given to me by Gary.

Perhaps by next week I will have some pictures of the fireflies!  However, even if I do not manage to capture their ethereal little flashes on film, I will happily enjoy watching them throughout the evenings.

DaisyPink_geranium3






Day_lilyRose2

June 24, 2005

Sailing on the York River

Yesterday, I had the wonderful opportunity to go sailing on the York River!  Greg, the Jefferson Lab Hall C staff scientist who has the office right across the hallway from mine, has a sailboat that he takes out onto the York River to enjoy the winds and race against a group of his friends who also have sailboats.  I have been interesting in trying this out, so I have been bugging him to take me sailing.  So, yesterday, he invited me to come along!  I was really excited about it (poor Vipuli had to endure me grinning about it all day).

At the end of the day, we zipped out to the slip and got everything ready to go.  As we motored down the creek out to the river, I watched all the herons and egrets fishing in the waters of the marshes the surrounded the creek.  The birds were absolutely lovely to watch, so graceful as they waded along the shoreline.  There were also ospreys everywhere.  Large osprey nests crowned the tops of every post that marked the boat channel in the creek.  Most of the nests had an occupant in them, so the birds would squawk at us as we passed by the channel markers bearing their nests.  They were really cool.  Later in the day, I even saw one flying along carrying a fish that it had just caught.

Paul2Once we got onto the river, we met up with Greg's friend Paul, and the race began.  We had a little trouble at first to get through the markers that designated the start of our course, but once we were through, we were zipping along splendidly.  The wind was lovely, and I got to experience how wonderful it is when the boat heels over at a steep angle.  I loved it!  It was so much fun!  I took this picture of Paul in his boat at a point when we were leading in the race.

SeanAt one point while we were zipping along, I took this picture of Greg's son, Sean, as he clung to the boat.  :)  We were having a great time!

After we rounded the marker that designated the end of the first leg of the race, Paul took the lead for a bit.  After we passed the second marker and started on the last leg of the race, both boats were very close.  We managed to just squeak past Paul at the last minute to slip through the markers that designated the finish line.  It was really exhilarating!  We headed back out (for our victory lap!), and Greg let me try my hand at sailing for a while.   He taught me a bunch of cool stuff about it, and then took a moment to take some photographs of me at the tiller.  In one of the photos, I am looking up at the little arrow on top of the mast that tells me which was the wind is blowing.  Sean and I are clearly having a good time!
SarahandseanSarahandsean2
It was a really great day.  It was sunset when we came in and docked the boat, so we all headed to Greg's home to have supper with Greg's lovely wife Claudia.  After supper, Sean and his twin brother Garrett completely obliterated me playing Halo 2, even though their older brother Ryan tried to rescue me at one point.  I don't feel too bad about it though, since I had never played Halo 2 before and have not played the original Halo in ages.  However, I will make sure that I practice before playing with them again!  Or better yet, I'll invite them to play with me in one of my favorite games....  :)

All in all, it was a great day (even though my hands were a little sore from tugging on all of those ropes).  I loved the sailing!  I can really see why people get addicted to this activity.  I'll close with a photograph that Sean took of me during the race.  Paul's sailboat is visible beside me, and you can just see Greg behind me.   Maybe I'll bug Greg to go again soon!  :)
Sarahsailing_1

June 22, 2005

The Poster Results Are In...

This morning, the results of the SURA poster competition were announced and I was so excited when my name was called out for the first-place prize!  :)  I am so happy about it!  I have been grinning so much today that my facial muscles are starting to get tired.  I couldn't wait to send an email message to the other G0 graduate students to tell them the wonderful news (they were happy too).  Jianglai and I went out to lunch to celebrate this afternoon.  It has been a great day.  Yay!

I was so excited about it all that it took me a while before I could concentrate on the two-photon exchange talks that went on this afternoon. :)

The second-place prize went to another William and Mary graduate student, my friend Chris Tennant, whose poster about beam breakup in the FEL (Free Electron Laser) I had been admiring during the poster session since it hung on the other side of the poster board from mine.  The third-place prize was shared by my friends Tanja Horn (a Hall C graduate student from the University of Maryland) and Peter Monaghan (a Hall A graduate student from MIT).  The SURA thesis prize this year went to Karl Slifer.  So, there were quite a few very happy people!  :)

The members of the G0 collaboration have been sending emails of congratulations, which makes me feel really good.  It is really fun to have so many cool people around! 

Slide1_1

June 21, 2005

Annual Users Meeting and the Poster Contest

Ugm_posterThe Annual Users Meeting is going on at Jefferson Lab right now.  This meeting is made up of talks and workshops about the research going on at Jefferson Lab, as well as planned experiments for the future 12 GeV upgrade of the accelerator here.  I have been going to lots of talks, but there is just too much information to absorb everything.  The new G0 results have been talked about quite a bit at this meeting, which quite exciting for me!

Yesterday was also pretty interesting since the poster session was last night from 6:00 - 8:00pm during the evening reception.   I was pretty enthusiastic about it, which was a really good thing, since my poster was very popular.  Lots and lots of people wanted to talk about G0, so I was kept amazingly busy all night.  Unfortunately, that meant that by the time the judges came by, I was getting pretty tired.  My poster was in the last part of those they were judging, so I am sure that they were getting tired too.  The judging was actually somewhat intimidating.  The four judges (who are all cool people, by the way) surrounded me in a semicircle and then told me how this would go.  I would have two minutes to explain the poster, and I would need to explain it as though I happened to be in an elevator with the person who would be granting the funding for my project and I needed to make my case and convince him or her that this was worth giving the money for.  Then, they would ask tricky questions.  Poster_session1So, I enthusiastically went for it and explained my poster (with 10 seconds to spare!!) and then tackled their questions.  I think that I did pretty well, despite the fact that I was getting tired and the format of the judging was not anything like I had expected (although I am not sure what I was expecting, since they had 25 of these posters to get through).  Admittedly, I am not sure how they will make the decision.  There were quite a few excellent posters there, and I know that the people defending them were really clever and knowledgeable.  Even so, I think that I did quite well, so I am hopeful!  The results are announced on Wednesday morning, so we shall see then...  :)

G0_forward_025Throughout the poster session Jianglai (one of the other G0 graduate students and my good friend) stayed nearby and helped me with the huge volume of people that came by to talk about G0.  Without him, my voice would have been gone by the time the judges got there.  We had a pretty good system going for a while where he stood on one side and I stood on the other, so we could easily talk to smaller groups at the same time.  I think that it would be good way of presenting any posters, and I also think that we made a really good team.  He also hung around and gave me moral support after the judges came by.  Thanks Jianglai!!  You are so cool!!  Here is picture of Jianglai and I in Hall C right after the physics run ended (taken by my friend Stephanie).  That is the G0 magnet right behind us.  We are pretty happy; after all, we have our thesis data!

Mark was also giving a poster (in fact, he was telling me that one of the questions that he kept getting asked was "Where is the G0 poster?"), as was Vince and several of my other friends.  I did not have the chance to take many pictures of what was going on, but Claire was circulating around taking pictures, so hopefully she was able to get some good ones.   Mark and Claire are heading back to South Africa very early in the morning (on Tuesday), so they will miss the announcement of the winners, unfortunately.  I have been teasing Mark that if he wins a prize, I am going to go and claim his money...  :)

After the poster session ended (Mark's poster was the last one judged), a group of my friends (Mark, Claire, Vince, John, and Rolf (our own Hall C leader)) and I went out to have some drinks and hang out.  We had a great time laughing about stuff and unwinding after such a busy day.   I am sad that Mark and Claire are already heading back to their country, but hopefully they will be able to come back again soon. 

We will see what happens on Wednesday!  :)
Poster_session2

 

Letter Update

Letter_from_representative1This weekend, I received another letter in response to the flurry of letters that I sent out in May concerning the proposed funding cuts for the physical sciences.  This letter came from the office of Congresswoman Jo Ann Davis.   I wonder if I will receive any more?  I am enjoying getting the letters in response!

At the Annual Users Meeting last night, Gordon Cates asked me if I would be willing to actually go and talk to the decision makers about the excitement of physics research.  I think that it would be a really fun and interesting experience, so I agreed.  We will see what I have gotten myself into now...  :)

G0 In the News...

Front_pageMy thesis experiment is now the first thing you see on Jefferson Lab's webpage!  That is pretty cool!  If you click on the story, it takes you to the news release at Jlab, which has links to a bunch of other press releases about the G0 experiment.  Cool!  :)

June 17, 2005

Lovely Day

Poster_drying2_1This has been a really lovely day!  Not only are the results of my thesis experiment now released, but I have finished and printed my lovely poster on the big poster printers in the document control group's rooms in the ARC building at Jlab.  It is a relief to have it all done and ready for the poster session and competition at the Annual Users Group Meeting on Monday evening.  All the comments that I received from the other members of the G0 collaboration about the poster were very positive.  I am encouraged about this; hopefully the judges will like it too!  I think that it is lovely.  :)  This is a picture of it drying, along with a lot of other people's posters.

The only bad part of my day came when another physicist disagreed with the uncertainty that Dave and I assigned to the polarization measurements for G0.  It is fine that he disagreed (such discussions often lead to improvements), but he was very unreasonable about it and would not listen to a thing I said about it.  He was very rude in that regard.  I was upset about it, but talking to Dave and Doug about it made me feel better.  No matter where one goes, there are always unreasonable people, not to mention that everyone has their unreasonable moments!  I am resolved not to let it bother me.

Picnic1_1The Graduate Student Association picnic/cookout that I have been organizing all week also went very well.  Lots of graduate students and post-docs showed up to enjoy all of the yummy food and hang out out with their other friends at the lab.  I had a bit of a panic when the guy that was going to be the grill-master backed out only a few hours before the picnic, but Victor stepped in and took on the chef's hat.  Despite the fact that the grill was being very contrary, Victor grilled the food with flair.  Here is a picture of him at the grill surrounded by friends.
Picnic3

Guy2_1I also ended up taking a picture of a guy who was absolutely insistent that I take his picture for some reason.   I tried to explain that I was not taking pictures for the GSA, but he wanted a photograph taken, so I did.  :)   It turned out really well, so here is the photo.  Maybe he will find it on this page and save a copy for himself!

Me_at_picnic1Ameya took a picture of me at one point in the picnic.  I look a bit tired, which is not surprising given everything that I was doing that day.

I had a great time hanging out with Claire and Mark and all the other graduate students during the picnic.  Hopefully, Claire was able to take more photographs than I was able to take, and will post them on her webdiary.  I think that everyone really enjoyed it.  I learned some things to do differently next time, but I think that it was a big success, especially for my first time organizing an event of this size.  I extend my thanks to the other GSA officers and all the others that helped in the clean up after the picnic!  :)

The G0 Results are Out!

Today was the big day!  This morning the spokesperson of my experiment (Doug Beck) gave a seminar at Jefferson Lab that showed our results for the forward-angle part of the measurement to the community outside of the G0 collaboration.  I was really excited about the seminar, and I thought that it went well andSeminar4 that the results were well received.  It is very exciting to see all that hard work pay off as everyone else finally gets to see what we have measured!   The results from the G0 experiment indicate that strange quarks in the proton's quark-gluon sea do contribute to the proton's properties (this has been hinted at by other experiments such as the HAPPEX ones as well).  This is a really intriguing result, so I sure that it will generate quite a bit of interest in the community.  Now that the results are public, I can finally talk to my friends outside of the collaboration about them!

The paper has been submitted to Physical Review Letters (one of the physics journals) today, and also to the e-print arXiv.  Once it appears there, I will post a link to the paper here.  Jefferson Lab also had a press release about the experiment today!

Below I have placed a photograph of some of the happy members of the G0 collaboration at the end of the physics running last May.  We all look quite happy!  :)

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Update from Monday, June 20, 2005

Here is the link to the pre-print paper for anyone who is interested!

G0gang8x10

June 16, 2005

Have the Data, now what?

Yesterday, I talked about all the cool equipment we used to take our data last year.  The period that the experiment was running was pretty long, and I took a lot of those long night-time shifts.  :)

Okay, cool.  Now you have a bunch of Tbytes of data tucked away on the Jlab storage silos.  Now what?  How do you get a meaningful (and publishable) result out of it all?

Well, this is the analysis part of the long road to a result.  You have to evaluate your data for any effects that have to be corrected and understood before you can announce your results.  For instance, in the real world , the polarization of the electron beam is not 100%.  It was actually about 74% for G0.  Since the asymmetry calculation assumes that you have a perfect polarization, you have to correct the numbers you get for the fact that in real life, it is not really perfectly 100%.  Another example would be what we call background, which is everything else that was going on in addition to what you were trying to measure.  A well-planned experiment attempts to minimize the amount of background stuff going on, since the signals that you are interested in can be swamped by too much background noise, but there is almost always some residual background no matter what.  So, when you are looking at the data, you have to be sure that you take this into account properly.  When you do an experiment like G0, you have to go through and make sure that you understand everything in your data, and make sure that you have corrected for all these things.

Once you have done all these things, then it is time to figure out the errors on the answer that resulted from the analysis.    All physics results are quoted with errors (or uncertainties), since no matter how carefully a measurement is made, there is no way for it to be 100% perfect.  The trick is to get the uncertainty on the measurement as small as possible.  This is done by a combination of ways: careful planning of the experiment so you have fewer sources of uncertainty, taking lots of measurements, and careful evaluation of all the possible contributions to the answer (among other things).  So, after you have come up with an answer, you have to evaluate the uncertainty associated with that answer.

There are two main types of errors that we quote on our results: statistical and systematic.  The statistical ones are easy to figure out.  For example, if you were timing how long it takes for the egg a friend dropped from the top of a ladder to hit the ground, the more times you timed it, the more confident you would be that your measured times were accurate, and not just a fluke.  This is why these sorts of experiments run for months and months at a time, so that they can make lots of measurements so that the statistical error bars are smaller because there is greater confidence in the results.  Statistical errors are pretty easy to evaluate, since the behavior is well studied and we have equations that describe it.

The systematic errors are harder to figure out.  What if the watch you were using to time the falling egg happens to run slow?   All of your  measurements for the time it took for the egg to fall would be be too low.  How could you figure this out?  The only real way to know for sure would be to test it against another watch.  This is a case of a systematic error, since all the results are skewed in the same direction.  Systematic errors can be difficult to evaluate, and since they are different for each experiment, they can require tests of the various ways that the error could be introduced.  You have to evaluate every sort of thing that might have gone wrong and had an effect on your answer.  This can be very hard...especially on a complex experiment. 

So, you spend months working on all of this, and making sure that everything in the data is well understood and accounted for.  By the end, you have the results!  When this point comes, the people in the collaboration review the numbers and decide whether or not to bless the results.  When everyone agrees, the results are released.  So, tomorrow, I will talk about the release of the G0 results!  :)

 

Tomorrow is the Day...

Seminar_announcement2Tomorrow is the day!  Our results will be released and there will be a seminar at Jefferson Lab.  I am pretty excited about it all.  :)  :)  After tomorrow, I will be able to talk about the results of my thesis experiment with other people outside of the collaboration!

My poster for the contest is out circulating among the collaboration, so I am here waiting for their comments on it while I work on the last details of planning for the GSA picnic tomorrow afternoon.  The five of us (the G0 graduate students: Jianglai, Kaz, Lars, Benoit, and I) think that it is pretty good.  I sure hope so.  I spent quite a bit of time working on it these last few days.  Tomorrow after the seminar, I will submit it to be printed on one of those big poster printers.  The test printings went well, so I think that it will print out nicely.  With any luck, I will present it well enough that it will win us the first prize! 

Tomorrow after the seminar, the Graduate Student Association is having a picnic cookout for the graduate students and post-docs here at the lab.  I have discovered that it is a lot of work to organize a picnic for a large group of people!  Victor, Ameya and I just did all the grocery shopping, and Peter and I have been tracking down and acquiring sports equipment all week for the activities.  I think that we will have a grand time.  I will be ready to celebrate!  :)

June 15, 2005

The Cool Stuff!

On Monday, I talked about what my experiment is trying to measure, and on Tuesday, I talked about the tool we used to make the measurement.  Today, I will talk about the cool stuff: the actual experiment and all the amazing stuff we used to measure an effect that is only a few parts per million.

The G0 collaboration has 108 members from 19 different institutions in four countries.  The design and construction of the experiment took place from 1993 through 2001, and in 2002, we had a commissioning run to test all of the new equipment that was built.

Picture1The G0 experiment took place in Jefferson Lab's Hall C last year (from November 2003 to May 2004).  For the experiment, the members of the collaboration built a new spectrometer (the detector and magnet equipment) that was installed in the hall.  Here is a picture of the spectrometer in the hall, with the various parts of the equipment labeled.  The electron beam comes in at the lower right-hand side of the picture.  For a sense of scale in the photograph, the ladder by the beamline is about 15 feet tall.

After the beam comes into the hall from the accelerator, its quality is monitored by the beamline monitors labeled in the picture and recorded.  Then it interacts with the target, which is located inside of the magnet.

The target for my experiment is 20 cm long, and filled with liquid hydrogen (which is mainly protons).  You can see the service module for the target in the picture sticking out of the front of the magnet.

Magnet_optics_1The huge toroidal magnet that you see in the picture is superconducting, which is why there are all those cryogenic hoses going into the top of it.  As the protons are knocked out of the target by the electrons, the field of the magnet bends their trajectory more or less depending on how much momentum they get in the interaction, so the magnet sorts them into the arc-shaped detectors.   Side_view1You can see this is the schematic that I have put on the left.  I have also put in a side view of the spectrometer on the right.  In the picture, you can see the target service module, the magnet, and the detectors.  There are also a couple of people in this photograph, so you can see how large the equipment is.

Sarahphillips_1The detectors are housed in eight octants that circle the beamline in the framework that we fondly call the Ferris wheel.  The detectors for the experiment are pretty interesting, since we basically have two sets: four were built by the North American members of the collaboration, and four were built by the French.  We built the NA ones here at Jlab in the cleanroom.  This photograph shows me and another of the William and Mary graduate students, my friend Allyn, working on the detectors.  The French octants were built in France, and then shipped over to Jlab and installed.  The detectors are made of a plastic that emits light when particles travel through them (they are called scintillators).  There are 16 pairs of them in each octant.  The first fifteen count protons that are scattered from the target, and the last pair measures background.

We have two sets of electronics, too: one system that reads out the NA detectors, and one that reads out the French ones.  The cool part about this is that it gives the experiment a built in cross-check, since both systems should give you the same answer. 

As the experiment ran, all the data that we took were written to storage tapes on the Jlab data storage silo (I actually got to see the silo and its robots during the Jlab Open House), where the data were ready to be retrieved and analyzed later.

Well, so much for the cool stuff we used to make the measurement.  Tomorrow, I will talk about what we do with the data once we have it!

June 14, 2005

How Do We Measure That?

Yesterday, I wrote about what my thesis experiment is trying to measure.  Today, I'll write about how we are able to measure this!

To make a measurement to look for the contribution of the strange quarks, we use a tool called parity-violation.  This sounds pretty complicated, but the idea is really simple.  The classic description is this: you make some measurements with an experiment in one configuration, and then you take the same measurements with the mirror image of the configuration.  If the results are the same, then parity is conserved; if they are different, parity is violated.  The electromagnetic force is mirror-symmetric (conserves parity), but the weak force is not mirror-symmetric (violates parity).

For the G0 experiment, we sent a polarized electron beam into a liquid hydrogen target (which is basically just protons).  The spin of the electrons in the beam were all lined up so that we could choose to have the spin pointing in the same direction as the motion of the electrons, or in the opposite direction.  For this experiment, this is taking the measurement and its mirror-image.  As the electrons collided with the hydrogen in the target, the detectors counted how many protons were knocked out of the target (or scattered).

We would take the measurement of how many protons were scattered for a certain amount of time with the electrons polarized in one direction, and then do the same measurement for the same amount of time with the electron beam polarized in the opposite direction.  The numbers are different, by about 10 parts per million or so, since because of the weak force the electrons polarized in one direction interact slightly differently than those polarized in the opposite direction.

This difference is very small, but very significant, since it tells us how much the weak interaction is present in the interaction, and by comparing this with the electromagnetic interaction, we can get the answer we are looking for: the strange quark contribution to the proton's structure.

Driving the Big Truck

Driving_the_truck1Gary and I had a great time at the milonga in Norfolk at Station 2.  This time, the kitchen was open, so I had the opportunity to sample the food.  The food was excellent.  I really needed a chance to unwind and have a good time dancing and hanging out with friends after having worked so hard on my poster for next week (and fretted quite a bit about it).

When we finally decided to head back to Williamsburg, it was pretty late, and Gary decided that he should not drive since he had been enjoying much more of a nice Merlot than I had.  So I got to drive the big truck!  I was really excited about it; after all, how often do I get the opportunity to drive in something that can easily plow over medians and people who don't bother to look or signal before they swerve into my lane?  Heh.  :)  Anyway, Gary took a photograph of me enjoying my time in the driver's seat of his cool truck.  I need to find a big truck somewhere so I can drive one more often.  :)

June 13, 2005

Hard at Work

So...  I am now working on my poster for that poster contest.

I am in that phase where I am thinking to myself "Why on Earth did I get myself into this?!?!"  I am at that inevitable point in a project where one despairs of ever sifting through the piles of information on the desk to end up with a vaguely coherent (let alone prize-worthy) poster that is somehow very intelligent sounding, but not terribly technical.  And even though I am promising myself that I will never ever get myself into this sort of thing again, I know that I will gleefully jump into this hole yet again... 

The only comforting thing is that Gary and I are going out to tango tonight in Norfolk, so I can only fret about this for a bit longer today.  Tomorrow is another day, after all!  The funny thing about it all is that since it is almost 6:00pm, I decided to change into my gown for the milonga tonight.  My officemate Vipuli took a great picture of me at my computer looking very decidedly not like a physics graduate student; I do look rather over-dressed!  I have also discovered that it is somewhat difficult to type in opera-length gloves.  :)

Back to talking about strangeness in the proton...at least for another hour or so...  Then I'll dance!
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Strangeness in the Proton?

I have been meaning for some time to do a series of posts about my dissertation research.  Since the release of our results is this Friday, I think that now is an excellent time to start talking about my thesis experiment, the G0 experiment in Hall C at Jefferson Lab.  With this in mind, I will attempt to write a bit about the experiment each day this week, and on Friday, I will talk about the release of our results and the seminar at Jefferson Lab!

As with any good experiment, the goal of the experiment is to answer a question: What role do strange quarks play in nucleon properties?  Like any good question, this immediately brings up yet another question: What on earth does that mean?

Simple_quark_model_protonProtons and neutrons (which we often just call nucleons) are made up of quarks (for an excellent resource on quarks and fundamental forces, go to Particle Adventure).  Protons are comprised of two up quarks and a down quark.  These quarks are held together by gluons.  In the simple picture, this is it.  In the picture to the right, you can see a simple schematic of this model.  But of course, things are never that simple!  :)

Not_simple_quark_model_protonIn reality, there is a sea of quarks and their anti-quarks that are always popping into and out of existence in extremely short amounts of time in addition to the three valence quarks.  And then there are all the gluons!  In the little diagram of this more complicated model, the squiggly lines are the gluons.  The three valence quarks determine nucleon properties such as overall spin and charge.  The sea around them is made of up and down quarks and their anti-quarks, which we will call the non-strange sea, and some strange quarks and anti-quarks, which make up what we will call the strange sea.  The non-strange sea up and down quarks do not change the properties of the nucleon, but they do contribute to the rest energy.  The strange sea quarks also contribute to the rest energy, and they are much more massive than the up and down quarks.  The question then is, do those strange sea quarks contribute to the electromagnetic structure of the proton? 

As physicists, we describe the structure of the proton with equations called form factors.  The point of this is to figure out the strange form factors, the equations that describe how the strange quarks affect the proton's electric and magnetic properties.

So, the goal of the G0 experiment is to learn more about the quark structure of protons and neutrons.  The focus of all of this is to determine the contribution of the strange quark to the electric and magnetic structure of nucleons.  Tomorrow, I will talk about how we do this!

June 10, 2005

Newly Discovered Music by Bach

Bacharia_pictureLast night I had the opportunity to hear a section of the newly discovered Bach aria on NPR!  I am quite excited about this whole event.  The fact that an aria by the great Bach has been rediscovered after almost 300 years is very cool and tickles my creative soul.  It also really interests me that the work, which is for soprano, strings, and basso continuo, was written as a birthday present for Duke Wilhelm Ernst of Saxe-Weimar (who was Bach's boss), and it also turned out to be a sort of "interview" piece, since sometime after he presented and performed it, Bach was promoted to the job of concertmaster and received a raise.

It is too bad that I am not so good at composing such lovely things; maybe I could get a raise! :)

June 08, 2005

More Jefferson Lab Wildlife

As I was walking to my car yesterday evening, I met up with another little animal that lives at Jlab and munches on the grass just like my muskrats that graze outside of my window.  This little rabbit did not seem too sure about me, but it didn't run away either.  It is a cute little bunny!

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June 07, 2005

Buttercups

Summer is here at last!  To celebrate, I am posting a picture of a buttercup that is growing in my yard.  I feel in need of a pretty flower today, since the code I am working on keeps crashing. 

I love buttercups.  They sing of summertime to me, the time of year when they cover the fields on my family's land back home in New Hampshire.  Hopefully I will get to see them in a month when I drop in to see my Grandmother on my way to Maine for the Gordon Conference.   :)

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June 06, 2005

Honeybees - Part I

Car_front1Well, I had an exciting and productive weekend.  I changed the oil in my car all by myself for the first time (well, Gary was in his garage working on his truck just in case I had any questions, but I did everything myself).  I feel pretty clever about it, even more clever than about the headlight bulb I changed about a month ago.  I don't have any pictures since my hands were all yucky during the process, but the whole thing was really cool.  I learned some cool things about it all (a few of these things I already knew partially, but sort of knowing, and actually doing are different things entirely):

  1. My pretty little car takes 5 U.S. quarts of oil when you also change the oil filter, which I did.  I put in five quarts of a super-duper, synthetic, heavy-duty oil for diesel engines by Amzoil (15W-40).  My car must find it pretty yummy, because she purrs along nicely.
  2. The used oil is very black when it comes out, blacker than I remembered.  It was about the color and consistency of the ink I grind from my ink sticks when I attempt to do some Chinese calligraphy or brush painting, although the consistency of the oil depends on the temperature, of course.
  3. It is an excellent idea to let your engine cool enough so that it is the above consistency.  That way, you don't burn yourself on the hot oil, but it still flows out pretty quickly.
  4. A 19mm drain plug is difficult to loosen while you are lying on your back under a car.
  5. I discovered that my arm is thin enough to thread an old oil filter through all the hoses in the engine compartment to place it in the full oil pan beneath the car without making a mess.
  6. You dab some fresh new oil on the gasket of the new filter before you put it on.
  7. The rocks in Gary's driveway are somewhat sharp.

It was all very cool.  And I feel pretty clever about it.

After I had finished with my oil change, Gary asked if I wanted to help him with his bees.  So, he and I spent the rest of the day pulling frames of lovely honey-filled comb from his hives and extracting it.  I took lots of cool pictures of the process, but unfortunately, they are all on Gary's camera, which is in Rhode Island with him right now!!  So, I will have to wait to talk about that until I can get my photographs.  Instead, I'll post some other pictures of his honey bees and talk about them.

Hives2Gary has three hives of honeybees that happily live in his back yard and forage for nectar throughout the area.   There are several different species of honeybees that are kept by beekeepers.  Gary has two species: Italians (Apis mellifera ligustica, these are also the species of bees that my parents had in New Hampshire) and Carniolans (Apis mellifera carnica).  They all make lots of honey that they store in the honeycomb in the hives.  Gary pulls the frames, extracts the honey, gives some to me to cook with, and makes mead with most of the rest of the honey.  His mead is quite good, by the way.

The photograph above is from early this spring, when it was still pretty chilly.  Bees don't like the cold, so they stay nice and snug in the hives on cold days.  The deeper boxes at the bottoms of the hives are the brood boxes where the queen bee lays her eggs and the workers tend them.  The upper, narrower boxes are the honey supers.  The frames for those are smaller because when they are full of honey, they are very heavy.  Gary forgot and put a brood box on top (the dark green one), and it weighed about 100 pounds when he pulled it off this weekend.  That is a lot to lift smoothly when there are lots of annoyed bees buzzing around you...

Filling_feeder2The bees forage on their own and pretty much take care of themselves, but in the early spring it is often a good idea to make up a sugar solution for them to start on.  During the cold winter months, their numbers decline somewhat, and if you feed them early in the spring, they build their numbers up much more quickly, so they have more foraging bees to send out once the nectar starts really flowing in the late spring.  So, at the end of March, when Gary was packing up all of his stuff to move to San Diego, my mother and I cooked up a batch of sugar syrup for his bees and loaded into the big five-gallon bee-feeder he designed.   It is pretty simple to do.  You just dissolve lots of sugar in the water and cook it until it is a fairly runny syrup.  In the photograph, you can see my Mom syphoning the syrup into the five-gallon bottle that makes up part of Gary's feeder.

Feeder3Traditionally, home beekeepers use inverted Mason jars with holes poked in the lids so the sugar syrup drips out, but the bees suck those dry very quickly, so the poor beekeeper has to fill them daily.  Feeder1Gary got annoyed with that and designed a five-gallon feeder so he did not have to fill it so often.  Even with so much, the bees empty it pretty quickly.  Here's a photograph of Gary with his feeder just after he finishing hanging it up. 

Beefeeder3_6820030001Here is a photograph Gary took of the bees on the feeder last summer.  You can see them clustered on the lower bottle.  He had dyed the sugar solution blue at the time, which is why the lower bottle is that brilliant blue color.  The lower bottle has lots of pinholes in it, so the bees lap up the sugar syrup through the holes.  If you look inside of the window to the porch, you can see a pile of new frames he was building for the hives!

Newhives_4may20040008Here is a picture of Gary with his bees not long after he got them and put them into their new hives last year.  Honeybees are pretty gentle; it this photograph, they are clearly more interested in working on their honeycomb than anything else.

I will close with the coolest picture of them all.  Gary took a picture of the bees flying around the bee-feeder one afternoon last summer.  In the photograph, you can see the differences in the coloring of the different types of bees (and you can see a couple of yellow jackets that also were attracted to the sugar).  The shutter speed of the camera was fast enough to freeze the motion of their little wings!  It is a lovely photograph.   Once I get the other photographs from Gary, I'll post those ones too and talk about how we extracted the honey from the honeycomb, which is an adventure in itself.  :)
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June 03, 2005

Happy Muskrats

It has been raining incessantly here for large parts of the whole week, which has really kept me from doing much outside.  The weather may be dreary and gray, but the muskrats sure love it.  I have been watching them play happily outside my window, splashing around in the puddles.  The dark pile of mud marks the entrance to the muskrat's hole.  They are such funny creatures!  Maybe I will go out and splash in some puddles for a while too...

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Competitive Spirit!

There is a new addition to the Jefferson Lab Annual Users Meeting this year: a poster competition for the graduate students!  And here is the best part: there is prize money involved.   The first, second, and third-place prizes will be $1000, $750, and $500, respectively.  That seems worth doing a poster over, not to mention the really cool feeling of having won something!

The posters will be judged on the clarity with which the student (or students) present their research and the quality of the overall presentation.   The rules say that the posters are not supposed to be overly technical, which is always a pitfall for me (and others, I've noticed) in these sorts of things.

After discussing it with the other G0 graduate students, the five of us have decided to submit a poster together, since we feel that this will give us the best chance of winning.   It will also be much more fun to work together, and that is the most important part.  I am really lucky in this regard; all the other G0 graduate students are really cool and fun to be around.  I am really excited about it; I think that we have a great chance of winning.

The poster session/competition takes place during the reception on the evening of Monday, June 20th, so we'll have to get going on it.  I'll keep posting updates on our progress and hopefully, our triumph!   We'll see how it goes!  I am sure that it will be fun.

June 01, 2005

A Letter from One of My Senators

Letters_to_congress1Well, I had a surprise waiting for me in my mailbox this weekend: a letter from one of my U.S. Senators!  Like the good little citizen that I am (and the good little physicist that I am, for that matter), I sent a flurry of letters to both of the men representing Virginia in the United States Senate, John Warner and George Allen, and to the woman who represents my district in the House, Jo Ann Davis, about my concern about the funding for DOE's Office of Science and the NSF. 

Letter_from_senator1I was not expecting to receive a response.  However, this weekend I discovered a letter from the office of Senator George Allen in my mailbox!  It is pretty cool, actually.  In the letter, he agreed with my views and outlined the things he is doing to support them.  I would like to get more letters that say, "Yes Sarah, I agree with you and this is what I am doing to make it happen".  :D    Maybe I should work on that...

So you see, it is good to be an active citizen.  Someone does read the letters!

Maybe I will get a response from Senator Warner next.  He visited Jefferson Lab last April as part of the ceremony celebrating the signing of the CD-0 for the Jefferson Lab 12 GeV upgrade.  I was one of the students who had the opportunity to tell him about my research while he toured Hall C.  From left to right in the photo you can see  Dr. Christoph Leemann, the Director of JLab; Senator John Warner; me; Kaz; and Kyle McSlarrow, then the Deputy Secretary of Energy.   We are all standing in front of the G0 spectrometer.  We'll see what is in my mailbox when I get home today...  :)
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