M. Zirdi Syukur

At A*STAR Q.InC, I contributed to the first half of a project to build a prototype NQR-based radio-frequency magnetometer for detecting unexploded ordnance and specific crystalline narcotics. When I left to pursue my MSc, the literature review was complete and the experimental setup had been designed and assembled for initial testing. The sensor is related to the QEP 2.0 Atomic Magnetometer, with RF and detuning coils, modular sample mounts, and pump-power amplification for RF operation.

I designed an experiment to investigate and test common assumptions made about spin-temperature equilibrium in hybrid alkali-vapour cells. In this project, we investigated the technique of hybrid pumping, which often increases the uniformity and sensitivity of atomic sensors; in particular, we wanted to experimentally observe how the efficiency of the technique diminishes beyond a certain ratio of densities within a hybrid vapour cell. The longer term goal is to improve vapour-cell uniformity and support more sensitive atomic magnetometers.

I built low-noise current sources and amplifiers to provide stable references for magnetometry experiments. Their radio-frequency noise performance was comparable to commercial instruments, including products that were difficult to obtain.

This undergraduate research project and my senior-year thesis at Yale-NUS College explored a Bitter-type bias-curvature electromagnet for ultracold lithium-6 experiments. The bias coils provide the strong magnetic field that tunes atom interactions, while the smaller curvature coils shape the field profile and can compensate its curvature. I used finite-element simulations to compare coil designs, then fabricated prototype coils and measured their magnetic-field profiles. These measurements supported a model of a strong, near-zero-curvature field, while full-power operation and the magnet’s cooling performance remained to be demonstrated.

The initial render of the electromagnets in Matematica

Animation of building the current's simulated inside electromagnets

Read about bitter-type electromagnets

Assembling the curvature-coil stack

Measuring the axial field profile

Modelled 832 G near-zero-curvature profile

This was an undergraduate summer research experience. One of the most important wavelengths for research in radio astronomy is 21cm. Galaxies are filled with neutral atomic hydrogen gas that emits strongly at this wavelength, making it an invaluable tool for research on nearby galaxies' structures, dynamics, and star formation rates. This wavelength is protected by international agreements but some countries are more zealous spectrum protectors than others. In this project, I make improvements to a small, portable, feed-horn style radio telescope in order to characterize the radio frequency interference (RFI) environment in Singapore near 21cm and to determine whether it would be useful to build a larger telescope on the Yale-NUS campus for teaching purposes in the future. Click here to download my presentation on the research

The Constructed Radio Telescope

Spectrums around 1.4 GHz produced with VIRGO spectrometer

Read about 21-cm Radiation