Alexander Merryman

As a Teaching Assistant for NEUR 2001, I have several responsibilities that can be split into two categories: helping faculty and helping students. One of my tasks is grading students' assignments and double-checking that the proper assignments and materials have been posted properly. When it comes to helping students, I hold a weekly recitation session that reviews the previous week's material, hold weekly office hours to answer any student-specific questions, and simply give advice and help the students in any way I can.

A cool fact about this project is that I started it in my first semester of college at Georgia Gwinnett College (GGC) before I transferred to Georgia Tech in the Fall of 2022. I am actually finishing up this project now and hope to submit my paper for peer review by the end of this summer (2023). A massive thank you to Dr. Tae Song Lee and Dr. Charles Pibel of GGC for their continued support of this project! Laser-induced breakdown spectroscopy (LIBS) has greatly increased its presence in the research realm in recent years due to its elemental analysis capabilities. These abilities come from the laser exciting the substance, which creates a plasma cloud that can be analyzed. This plasma contains excited electrons that emit certain light wavelengths. Similar to density or the atomic number of elements, each element has unique wavelengths that can almost be used as a “fingerprint” to determine what is present in the substance. However, professional LIBS systems require resources that are neither abundant nor readily available, such as lasers built specifically for LIBS. A more accessible option is the use of a cosmetic pulse laser. Cosmetic pulse lasers are common in tattoo removal and utilize a Q-switched Nd:YAG laser with a dual wavelength of 1064 nm or 532 nm. Because the laser pulse has an energy of about 100mJ and only lasts a few nanoseconds, the laser has high power (Power = energy/time). Similar to a professional LIBS system, there are certain structural elements needed for experimentation. An enclosure that houses the laser, sample, and fiber-optic cable is needed in order to ensure the wavelength of the plasma is measured and not that of the surrounding light. The light emitted from the excited substance is captured by the fiber optics and sent to the spectrometer (Aurora 4000) for analysis. The great thing about this LIBS system is that many trials can be completed in a short amount of time. With many trials, the objective is to determine whether or not a LIBS system utilizing a cosmetic pulse laser is effective in identifying elemental substances. The cosmetic pulse laser LIBS system should accurately classify pure substances as long as the set-up and procedure are completed correctly.