• LANL*

    Posted on June 14th, 2009 Martín Di Stefano 2 comments

    Hey everybody!

    Sorry it’s been so long… We had quite the experience trying to get a steady internet connection set up in our apartments. Anyway, this would be the much awaited ‘physics post’ for my research experience (although I’ll probably take up more space writing about non-physics stuff).

    For those of you who hate condensed versions and like the drawn out version with way too many technical terms, you can see what my project is all about here. This is the article that my mentor (Josef) and his colleagues have already published. Here is the condensed version:

    My project’s goal is to develop a new method for calculation the magnetic drift invarient L* used in many space weather applications.  I’m sure many of you know what L* is, but here’s a little refresher straight from Josef’s paper: ‘L* is dircctly proportional to the integral of the magnetic flux contained within the surface defined by a charged particle moving in the Earth’s geomagnetic field.’ The problem that we face when calculating L* is that, typically, an L* calculation can require ~10^5 calls to a model. This takes a LONG TIME! To put it in perspective, each call takes about a minute on the computers here (wait ’til I tell you about the cluster I’m going to be working with!). Doing some simple math (1*10^5), that would take 100000 minutes! I don’t know about you, but I just don’t have the time to sit around and wait for that. What Josef has been working on (and what I’m now working on), is to develop a neural network surrogate model that can calculate L* millions of times faster than the standard direct integration techniques. The neat thing about a charged particle’s motion through Earth’s magnetic field is that it remains ‘trapped’ in certain places (provided it does not get lost in the Earth’s atmosphere or travel past the magnetopause). The particle exhibits three types of motion – gyro, bounce, and drift. The gyromotion is the partcle circling around a magnetic field line. The bounce is the particle ‘bouncing’ up and down along a magnetic field line. This motion depends on the particle’s pitch angle with respect to the magnetic field line. The last motion is the particle ‘drifting’ around the Earth, parallel to the magnetic field lines.

    That’s about it for the physics part – my main job here at LANL is to train a neural network (a big-@$$ computer network) to learn what results come from what input parameters. I think about it (not sure how correct this is) as giving the computer examples and building up its ability to instinctively spit out an answer. Someone who is more computer-savvy might want to explain the exact workings… So basically, my job is to provide the network with many real examples (from data collected the past four decades) and then validate the results with other sets of data that the network hasn’t seen. LANL came up with a clever name for their model of L* – LANL*!

    So far, I’ve been stretching my brain to learn Python (yes, named after Monty Python!) and understand what Josef already has written. I have already written a couple of scripts that call upon the 40 year data table and organized that data into dictionaries in Python (basically a list with many key-value pairs. ex: key-value=’Year’-1963). Then I also wrote a script that transforms TAI (I think) time value, which is basically seconds since the start of 1958, into a human-understandable reading of day-month-year-hour-minute-second. So far it’s been a lot of fun using Python and troubleshooting on my own. I highly suggest all computer language illiterate people to at least try some simple stuff with a language. I’m not claiming I’m an expert, but it has been a very enjoyable experience so far, not to mention it will be very useful in the future.

    This week was very exciting for me because I was finally told to log in to the computer cluster that I will be working with. I don’t know how much I can tell you about the cluster because I haven’t been able to find public info on the web. It is only described on LANL’s internal network. But I can tell you that it is monstrous. I get nervous everytime I log in to the cluster through my terminal. Oh well, maybe I’ll get used to the idea of having tons of computing power at my fingertips…

    Well, enough talk about work. This past week we went hiking to three different places. We went up Pajarito Ski Area, down Hamilton Camp Trail, and up Cerro Grande in the Jemez Mountains. Tons of fun. I just realized I don’t know how to put a picture in here… That’s sad. A little help, Isaac!!

    So, I guess I lied when I said there would be more non-work writing. I’ll get some pictures up and expand on my social activities once I figure out how…

    Hope everyone is enjoying their summers!

    -Martín

  • Welcome to the Atomic City!

    Posted on June 1st, 2009 Martín Di Stefano 6 comments

    Hello again!

    Well, I finally made it to Los Alamos! The 17 hour drive wasn’t very exciting, especially driving across Kansas diagonally! I left on Saturday after having only 36 hours at home (should have been more but my car broke down coming back from KCI). I decided to knock out 10 hours the first day so that I could get to Los Alamos early afternoon. I stopped in a little town in SW Kansas called Liberal. Pretty neat town besides the moldy gas station pizza. Apparently, Dorothy Gale’s house is in Liberal – complete with a yellow brick road. They also have the Mid-America Air Museum! It has over 100 aircraft and other neat stuff. As you can tell, I got really excited when I heard that, but they had already closed for the day by the time I arrived in Liberal. I think I’ll stop by on my way back in August.

    I made it to Los Alamos around 1500 logging 989 miles at an impressive 33.6 mi/gal. The student housing (University of New Mexico – Los Alamos) isn’t exactly what I expected. The way the website described it, I was under the impression that I would have a decent kitchen, bath, walk-in closet, and living area. Instead, the living area has our beds, a couch, a tiny table, and one desk (for two people!). The walk-in closet is ok, and we got two dressers. The bathroom is pretty cramped, and I would describe our ‘kitchenette’ as a ‘kitchen-in-a-closet.’ Double doors open up to reveal 3 feet of linoleum and a stove, sink and cabinets. In all, I can’t really complain – UNM just needs a better website. And besides, I’ve already met a good number of awesome people that should hopefully make my summer here somewhat exciting.

    Speaking of exciting, the materials science department here at LANL disposes of their expired explosives every summer in a huge event for the student interns (about 1,200 in all). They claim that the best/easiest way to dispose of explosives is, well, to explode them. I can’t wait for that.

    I had my first day of work today. I got up around 0700 and took a van provided by my program to the badge office at LANL. I got my ID card and got a chance to swipe it to get through a security checkpoint. Pretty exciting! I made the mistake of wearing a blue shirt for the photo, so now my ID card has my head floating on a blue background (the backdrop was blue). After that, I went to meet my mentor. We work in an old metal building on the edge of TA-03 (Technical Area 03). The quickest way to it from parking is via a dirt trail through some back country along the edge of a canyon. I love that the lab is set in the middle of mini mountains.

    I toured our building and met some of the other employees. LANL is divided into workgroups, so there are mini work communities that do weekly lunches and dinners together. My office (yes, an office!) is not what I expected in a national laboratory. It’s just an average room. I do get my own computer with two monitors on a pretty big desk. I share the room with Misa ___. I think she’s an intern because all the permanent employees look like they are at least 30, but I’m not really sure. The people here are really laid back. They’re the mountain loving type who mainly like to have a good time while keeping their brains active and interested in the world around them.

    I had to complete a couple of training excercises on the computer regarding information safety and drug abuse. I got a kick out of the information safety program because it kept referring to ‘bad guys.’ Does that make me a good guy? Other than that, the whole thing was kind of boring. After that, Josef (my mentor) explained the physics to me, showed me what I would be doing, etc. We then went to a seminar on neural network methods (my project for the summer!) that was way over my head. They guy giving the talk was from Germany. I spent the rest of the day toying with and trying to understand Python. I also started reading from a book Josef gave me on space weather. I’ll save the physics details for a little later when I get a better understanding of it and what I will specifically be doing so that I can talk about it all at once.

    I got home from work around 1700 and had some rice and eggs from last night. I’m going to go play some basketball with some friends tonight. We got the basketball at Wal*Mart last night. We had to make an emergency run because a couple of guys didn’t have bed sheets. The Wal*Mart was about half an hour away in Española, but at least it was a fun drive through the curvy, cliffhanging roads.

    Well, enough for now (and I wondered how everybody else was writing such long posts…). Off to get some excercise…

    -Martín

  • Pre-REU in Buenos Aires, Argentina

    Posted on May 23rd, 2009 Martín Di Stefano 2 comments

    ¡Hola! I’m Martín Di Stefano, Kirksville native. I just finished my second year in Truman’s physics program (BA) with a (as of now undeclared) math minor with a pre-engineering concentration. I am on track for the 3+2 program and will be leaving Truman after the Spring 2010 semester to continue my education in Aerospace Engineering.

    I’m currently in Buenos Aires, Argentina, visiting my extended family. It’s awesome here. This is my sixth or seventh time here (maybe – I’ve lost count), but this place never ceases to amaze me. With all the wonderful food, crazy fútbol games, and beautiful winter weather (70°F), I want to throw away my return plane ticket. On the other hand, I have an exciting summer ahead of me at Los Alamos National Laboratory.

    I will be working with Josef Koller at LANL on a project tracing particles through our planet’s magnetic field. So far, I’ve had to do a bit of ‘homework’ before I arrive at LANL on June 1. My first ‘homework’ was to research a bit on numerical methods. I turned this into real homework by making it my topic for the term paper for Math Phys. My second assignment is to read up on the basics of Python. I’m working on that in my spare time here in Buenos Aires.

    I don’t have much more to say for now – I think I’ll just go enjoy my final days in Argentina before reluctantly getting on the plane next Wednesday (May 27).

    -Martín