This is the second part to my post on my Graduate School Year-In-Review 2017-2018 where I write about my experiences as a teaching assistant in the Physics department, my lab rotations with Wendell Hill and Amy Mullin, and some of my extracurricular activities.
Teaching Assistantship
Being a teaching assistant was a valuable experience to me. After all, I have spent most of my education not really knowing how things operated from the instructor’s side, so finally, as a graduate student, it was about time that I knew what was up.
Initially, I was assigned as a teaching assistant for the Physics for Life Science Majors course, taught by Edward Redish (nuclear physicist), and was part of the Physics Education Research initiative that looked for ways to improve the traditional method of running a class, in this case, for students who are more math adverse. I remember running those couple of first recitations by myself trying to figure out ways to keep the students on track, and discovering that students will tend to be more engaged when you personally go up and break the ice with them. Later, it was announced, that another graduate student who had prior experience in physics education, who had not been previously assigned to this course wanted to come in. This meant someone inside had to get out and TA for another course, namely the experimental physics course on electronics for physics majors. Initially, Rahul Gaur, a graduate student specializing in theoretical plasma physics, volunteered for it, but I also offered to switch in case Rahul’s schedule prevented him from doing so. In the end, I switched out.
It was an uncomfortable affair, but the bright side is that the class I switched into was designed to teach students the electronics skills to eventually build
an AM radio, complete with speakers made of plastic plates, by the end of the course. As a Signal soldier who had spent a lot of time working with radios
in the Army, but never truly understood how the internal components worked, this appealed to me. Not to mention, I had never taken an electronics course
during undergrad, so there was quite a bit for me to learn from the course, personally. My TA assignment involved working for two different faculty members,
Frederick Wellstood and Sarah Eno, both experimentalists (obviously). Fred Wellstood wrote the book on electronics (at least the one used in the course) and
it was very often a pleasure working alongside him in class and being able to ask him questions of my own. Sarah Eno ran her courses differently from Fred’s
in that she had her students pair up and rotated the pair assignments every week, a great way, in my opinion, to get students integrated with one another.
Having a diverse group of students in the same classroom is one thing, but having them integrated is another. Sarah also gave a lot of good career and
academic advice. I learned quite a bit from this course and have become inspired to seriously get a ham radio license, once I get the time to do it, that is.
Having TA’d for the electronics course and being one of Wendell’s research assistants, I was able to pull a few strings to get me assigned as a TA for the next course in the experimental physics sequence, which covered lasers and optics. This course was taught by Wendell himself, with Andris Skuja, elementary particle experimentalist, running one of the lab sections and filling in for Wendell in his absense. This was also a course which delved deep into the fundamentals of experimental methods (this time, with lasers) which I never learned as an undergraduate. It also had a theory component, with biweekly homework assignments, which I admit, wasn’t easy material and could even be a large part of an independent course on its own. I gained a lot of useful knowledge about lasers which I did not have before, in particularly, modeling them as Gaussian lasers and important parameters such as the Rayleigh range, which comes up often in research. Grading homework as well as lab notebooks was a lot of work, and had I not been busy with classes of my own, I probably would have done a better job as a TA, despite the fact that I felt like I was probably already exceeding the 20 hours a week expected time commitment on average.
Laboratory Rotations
My first lab rotation was done with Wendell Hill’s lab working with his graduate student Davy Foote. Prior to the Fall 2017 semester, I had already been
working in this lab in the Summer running simulations on strong-field ionization of atoms and reading about strong-field laser physics. In the Fall rotation,
I learned how to turn the laser on and off, and obtained a lot of practice during my regular visits.
I was also given the project of working on cross-correlation frequency resolved optical gating (XFROG for short), which was a method of characterizing an
unknown laser pulse using a known laser pulse which can be of a different central frequency. Normally, the FROG method is used for characterizing laser
pulses, since that only requires the unknown pulse to gate itself, which is actually used for characterizing the lab’s Ti:Sapphire generated 800 nm pulsed
laser; however, our situation is such that the unknown pulse we were working with is the second
harmonic generated 400 nm pulse created from the 800 nm pulse. Optics equipment, such as mirrors, lenses, and crystals, tend to be optimized at
particular wavelengths and we did not have the equipment to build a separate FROG for the 400 nm pulse. The XFROG became an economical choice, as it requires
only the addition of either a sum-frequency generation (SFG) crystal or a difference-frequency generation (DFG) to create the signal needed for analysis.
We started with the SFG crystal, but despite all of our best efforts, we could not find the signal. The DFG crystal was able to generate the signal needed.
The data was taken meticulously by hand, and due to the lack of accuracy of our manual translation stages, resulted in low resolution. The next problem was
that an XFROG analysis has never been done before in this lab. By scouring online, I was able to find an XFROG algorithm written
in MATLAB by a researcher in ultrafast lasers, and we ran it with some issues. By the time we got to this point, I was at the end of my first semester. It
was some time after I had given my end of rotation presentation that Davy had discovered that the FROG software he had normally used for FROG analysis also
has the option to perform XFROG analyses. During this time, he had also bought a motorized translation stage that would help increase the data resolution,
whilst advising undergraduate research assistant Sara Negussie and high school assistant Emma McMillian [sic?].
It was a frantic effort looking for a lab to conduct my second rotation in. Lab rotations existed since only a couple of years ago and are currently only part of the Biophysics and Chemical Physics programs, but not in the Physics program, therefore faculty members were not very familiar with it. I could have continued working in Wendell’s lab, but Dr. Papoian had recommended that the rotations are done in different labs, as their purpose is to help expose students to different types of research and better inform their choice of research advisor. I had inquired a good number of professors, to include Howard Milchberg, Rajarshi Roy, Paul Lett, Gretchen Campbell, and Mario Dagenais, and it was a last ditch effort perhaps a couple of weeks into the the start of the Spring semester that I asked Amy Mullin. Davy was the one who told me about Amy’s group and, being the Physical Chemist in demand, she had been in Davy’s dissertation committee. After meeting with her personally, she decided that it would be best for me to work in her optical centrifuge lab, with Chemistry graduate students Hannah Ogden and Tara Michaels. The optical centrifuge lab conducted research on generating and measuring linear molecules, and a couple of papers had been published the recent years prior with Hannah as an author. Amy Mullin had let me borrow her Atkins Physical Chemistry textbook and marked the sections on rovibrational spectra to study. I was shown how to register for the Hitran database (which, similar to the NIST atomic lines tables, is a collection of lines resulting from rovibrational transitions), how the optical centrifuge laser system as well as the IR spectroscopy measurements were set up. I was invited to the Chemistry prospective graduate student visit day as well as Tara’s practice oral presentation exam, which Chemistry graduate students are required to complete to reach candidacy. Her presentation was on collision systems between molecules and atoms, which dives deeper in figuring out why rotating molecules relax in the presence of buffer gases the way they do. Due to heavy commitments from classes and being a TA, I wasn’t able to accomplish much as far as a lab rotation project goes, but I was able to learn a lot from reading their papers and being in the lab those times that I did. I also made new friends, saw familiar faces in the Chemistry department whom I had taken courses with the semester prior, and learned a lot about the science community in general. Pursuing this second lab rotation had helped me build new bridges, which is one of the joys of being in an interdisciplinary field.
Extracurriculars
There wasn’t much I could have been able to fit in my schedule as a first year graduate student, but when I had arrived in Maryland, my contract with the US Army Reserves was still in place, so I was under obligation to seek out a unit locally and continue coming to Battle Assemblies. By utilizing my resources, I was able to find a unit to conduct drills with. For OPSEC reasons, I will only use generic descriptions. My experience with this unit was quite memorable and beneficial as far as personal development was concerned. Their 1st Sergeant had quite a force of personality. Being a signal sergeant, I worked mainly with the unit’s communications soldiers, but contributed wherever I can, to include running a PT event, because that’s what NCO’s do. Some of the highlights spent with this unit included watching an airborne jump, setting up and firing .50 cal machineguns, and spending a night in a tent in subzero weather. I was also able to learn a bit about communications as this unit’s comms, which required a whole section to manage, was more advanced than that of my previous unit, whose comms I essentially ran alone with some help (ok to be fair, quite a bit of help). One of the comms sergeants was a former infantryman and I learned quite a bit from him. Eventually, my ETS date came, and it was time for me to set aside the uniform.
A few members from this unit later organized a team to participate in the George Washington’s Birthday Marathon relay. I decided that, since I was not too shabby at running, I should join in. I trained through the winter for this event, wearing tight leggings and a long sleeve shirt for my runs. What helped motivate me to push myself on my training runs was the running scene from Lone Survivor where Lt. Michael Murphy raced against PO Danny Dietz around the military compound while guitar music and snare drums played in the background. My goal was simply to get myself to the point where I can decently run one leg of the marathon, which turned out to be 9.3 miles. It wasn’t anything too impressive. During my training runs, I went at most as far as 6.8 miles. I was pleased that I was able to maintain my same pace for the relay event for the entire 9.3 miles, which was a bit under 8 minutes per mile. I got to know these servicemembers at a more personal level and look forward to future events like these, hopefully.
I had also trained and participated in the Terrapin triathlon (which ended up being a duathlon due to the cancellation of the swim event because of the cold weather, which was 30-40 degrees Fahrenheit). In retrospect, I am really glad they did this, because I was already hurting pretty bad on the bike ride, with my hands getting numb due to the wind. It is still disappointing since I can’t in good conscience count this as a triathlon. This means I still have only ever completed one triathlon in my life, and that was the 2016 Ironbruin at UCLA.
Fin.