Tuesday, July 1, 2014

An Interview with Dr. Dipak Rimal

Dr. Dipak Rimal recently defended his PhD in experimental nuclear physics, and joined a post-doctoral research associate position at the University of Florida. He was born and raised in Baigundhura VDC in south-eastern part of Nepal. We are pleased to have Dr. Rimal in my frame of reference!

Please tell us about yourself, and your journey to USA for higher education.
I was born and raised in Baigundhura VDC in south-eastern part of Nepal. My father was a local educator, and had a great appreciation for science and technology. His constant motivation and inspiration lead me to pursue higher education in science. After passing the School Leaving Certificate (SLC) exam from Shree Amar Madhyamik Vidhyalaya in 1995, I went to Birat Science College, Biratnagar to study science (I. Sc.). I then went to Tri-Chandra College for Bachelor's degree. Since I graduated as a physics major with minor in chemistry and math, I got admitted to the Central Department of Physics (CDP), Tribhuvan University for M. Sc. in Physics. After graduating, I taught undergraduate level physics courses at Xavier Academy, Lazimpat for two years. In the fall of 2007, I moved to Miami after I got admitted into the PhD program at the Department of Physics at Florida International University. I recently graduated from FIU with PhD in physics specializing in experimental nuclear physics.
Could you please describe your PhD research in plain English. (Einstein once said, “If you can't explain it simply, you don't understand it well enough.”)
My PhD research was in the field of experimental nuclear physics. My research was primarily focused on expanding our understanding of the electromagnetic (EM) form factors of the proton, the positively charged core of the hydrogen atom. The EM form factors of the proton are the most fundamental observables, which encode information about the charge and magnetization distribution inside it. Even though the proton has been studied for several decades, a lot remains to be understood about the electromagnetic form factors in order to completely understand the structure of the proton. A significant discrepancy exists between the results from unpolarized and polarized electron scattering measurements of the EM form factors. This discrepancy casts a serious doubt on our understanding of the proton electromagnetic form factors and also on several other observables derived from these form factors (for e.g. proton charge radius). I don’t want to go into details here but plausible theoretical explanations for the cause of this discrepancy have been proposed. Rigorous experimental tests are necessary to make a definitive statement about these explanations. In short, my research was focused on the experimental test of the proposed theoretical explanations.Our team produced an intense matter/anti-matter mixed beam (electron/positron) from a 5.6 GeV primary electron beam at Jefferson Lab. Ordinarily, the matter and anti-matter particles would annihilate releasing the energy in the form of photon. To keep the particles intact, the electrons and positrons were spread over a distance of a few centimeters. The mixed matter/anti-matter beam was then scattered from a liquid hydrogen target, kept at the center of a giant spectrometer known as CEBAF Large Acceptance Spectrometer (CLAS). The elastically scattered electron, positron, and the proton were detected in CLAS. The detected particles were then analyzed to compare the positron-proton and electron-proton interactions.
What are the social applications of your research/ short-term or long-term impact of your research to the society.
My research, being a fundamental science research, may not have immediate social applications. However, in the long run it will reshape the way the electron scattering data is analyzed. My research was intended to test theoretical explanations for the discrepancy between different methods of measuring the charge distribution inside proton. These results will help make a definitive statement about the explanation for a decade long scientific puzzle.
How was your graduate school experience? (Specifically skill(s) you needed to sharpen etc.)
My graduate school experience at FIU has been memorable one. Since we had a lot of fellow Nepali graduate students in the department, the physics department at FIU felt like a second home. I feel lucky that I had an excellent advisor who provided me an opportunity to work in a large international collaboration comprising of scientists from all over the world. I had to learn UNIX/LINUX operating systems, and learn programming languages. I also had to sharpen my problem solving and experimental skills.
Please share few useful tips that you wish you were told when you applied for PhD.
I wish I had learned at least one programming language before I applied for PhD. I wish I was told to learn problem-solving rather than memorizing physics derivations.
Where do you want to be in the next 5 years? What are your hobbies, and spare time activities?
Umm! This one is the hardest one. I don’t really know! I just started working as a post-doctoral research associate at University of Florida. I will be working on MINERvA neutrino experiment at Fermilab to investigate neutrino-nucleus interactions. Let’s see how next 5 years unfold but I definitely want to see myself in a pretty good shape in terms of research. Regarding hobbies, I enjoy visiting new places. I follow world news to keep myself up to date with the recent happenings around the globe. I am also a big time sports fan. In the spare time, I enjoy watching professional leagues and college sports.