The bunch length of an electron beam can be determined by using a Michelson interferometer to measure the auto-correlation of the coherent transition radiation (CTR) signal emitted by the beam after passing a solid target. In the UCLA MITHRA beam, this measurement will be taken by a Bunch Length Interferometer System (BLIS), which involves moving a translational stage in the interferometer to vary the delay of the two signals, reading the spectral power at each delay with pyroelectric detectors, and processing the CTR scan with time-domain fitting (A. Murokh, et al., NIMA 420, 452, 1998) and the Kramers-Kronig reconstruction (Lai & Sievers, PRE 50, R3342, 1994) algorithms. An automated Python script has been developed to take the scan, record data, and process data all at once. The script integrates communication with a motion controller and an oscilloscope to take the CTR scan, consolidates the raw data, and then processes the data with both algorithms. This method will be tested to measure bunch length in the MITHRA beam. Bunch length is a critically important diagnostic, and its measurement and subsequent optimization will facilitate experimental measurements using the beam, including but not limited to plasma wakefield accelerator and advanced dielectric wakefield accelerator experiments.

One of the focuses of the Caram lab is research involving J-aggregates that exhibit a red shift to the more “spectrally quiet” region of the electromagnetic spectrum, or IR. Cyanine dyes commonly exhibit this type of aggregation. For this project, we wish to explore the common cyanine dye 3,3’-bis(2-sulfopropyl)-5,5’,6,6’-tetrachloro-1,1’-dioctylbenzimida-carbo-cyanine (C8S3) dye which forms tubular J-aggregates. Interestingly, when silver nitrate is added to these tubular aggregates and irradiated with light, strange changes occur to the spectral absorption graphs, indicating that the silver ions interact with the iodine counterions in solution with these aggregates. We hypothesize that a silver iodide nanowire is formed within the tubular J-aggregate and seek to prove this using spectroscopic methods. The initial stage of this research involves experimenting with different conditions to create these silver iodide nanowires. Next, we experiment with different techniques to isolate the silver iodide nanowires. The long-term goal is to conduct experiments detailing the optical and electrical properties exhibited by these nanowires and explore potential applications in semiconductor research and the ability to template nanowires to a specific diameter as set by the nanowires.

Flash memory is a type of non-volatile memory that stores data for many applications including flash drives, laptops and mobile phones. Flash memory can maintain data even when a device is powered down by storing charge in billions of flash transistors, or flash cells. Information is stored in a flash cell as an amount of charge or lack thereof. For each data input, a specified amount of charge is applied, or programmed, to the flash cell. This charge induces the voltage level at which current will flow through the transistor. Read thresholds are voltages applied to a flash cell to read the data by checking if the voltage level that induces current flow is above or below the threshold. The operations of storing charge and later removing it from the flash cell degrade the cell over time. This research finds optimum hard and progressive read thresholds and voltage levels to maximize the minimum mutual information between an input data bit to a flash cell and the read results. As an example, we use MATLAB to optimize the write voltages and read thresholds for a Multi-Level Cell (2 bits of data). Optimizing voltage levels as well as read thresholds increases the minimum mutual information of the two bits which delays the failure of the weaker bit. Therefore, this research provides a technique to improve the performance of flash memory. As flash memory is widely used for data storage, increasing device lifetime has wide-reaching impacts in data integrity, sustainability, and decreasing costs.

Poly (lactic-co-glycolic acid), or PLGA, is an FDA-approved biodegradable polymer which has been extensively studied for drug delivery. Previous work has used PLGA microparticles to encapsulate β-glucan for temporal control of trained immunity. Additionally, recent studies reveal that some small molecules are able to induce trained immunity in vivo and in vitro. However, it is unclear whether PLGA encapsulation can affect these small molecules’ ability to induce trained immunity in vitro. In this study, we investigated the relationship between PLGA-encapsulated myricetin nanoparticles and their ability to induce trained immunity in vitro. We found that the previous protocol for making PLGA nanoparticles required optimization to produce a high yield and sufficient encapsulation efficiency. However, we were able to increase the yield from around 10% to 60% and the encapsulation efficiency from 2% to 95% by optimizing the amount of PLGA used, centrifugal force, and wash method. Further study with bone marrow-derived macrophages (BMDMs) showed that our PLGA nanoparticles could induce pro-inflammatory trained immunity responses in vitro, and PLGA encapsulation did not significantly alter the drug’s properties compared to free drugs. Our results provide an improved methodology for synthesizing PLGA nanoparticles with high encapsulation efficiency and similar properties to free drugs. This work allows for future passive targeting of phagocytic cells in vivo, which may prevent off-target effects by the drugs used to induce trained immunity in these cells of interest.