Our celebration of Dr. Hao Lu's successful doctoral dissertation defense, with his supervisor, Dr. Mike Snow.
Dissertation Title: Neutron Birefringence Measurements of 129Xe, 131Xe and 3He
Abstract: Understanding the spin-dependent neutron scattering lengths of 129Xe and 131Xe is essential for the interpretation of spin-dependent neutron-scattering studies on polarized Xenon ensembles with possible future applications such as tests of time-reversal violation.
I present the first measurements of the spin-dependent incoherent scattering lengths (bi) of 129Xe and 131Xe, along with a fresh independent measurement for 3He for comparison with existing literature. We used the Jülich Neutron Spin Echo (J-NSE) spectroscopy instrument at the FRM II facility in Germany, where the neutron beam traversed nuclear samples with alternating positive and negative polarization states, resulting in a variation in the NSE interference pattern.
The spin-dependent neutron incoherent scattering lengths measured to be: bi(129Xe)=−0.186±(0.021)stat.±(0.004)syst. fm and bi(131Xe)=2.09±(0.29)stat.±(0.12)syst. fm. Additionally, the incoherent scattering length of 3He was independently determined as: bi(3He)=2.280±0.020(stat.)+0.015(syst.) fm, showing agreement with prior researches within two standard deviations. Further experiments were designed and executed to address this discrepancy.
