E19013 - Last MoNA Experiment of the CCF era, completed!

With a Herculian effort by all the NSCL/FRIB members of the collaboration, a complex triple coincidence experiment to explore reactions leading to 12Be in the final state. The neutron-unbound nucleus 13Be is known to decay to 12Be + n with a relativley low resonance energy but previous experiments had left it unclear whether the ground state of 12Be or its 0+ isomer was populated in the final state. This leads to a significant ambiguity in constructing the level-scheme. To resolve this ambiguity, we performed a triple coincidence (fragment, neutron, and microsecond-delayed gamma-rays). This experiment was run in September of 2020 during the COVID pandemic. A small group of faculty, staff, post-doctorial researchers, and graduate students setup, ran the experiment, and packed away the devices. This invloved moving several miles of cables, a few tons of detectors, and synchronizing three distinct data acquisition system. Many thanks from the rest of the collaboration!

Figure 1: Experimental setup showing CAESAR (CsI) surrounding the charged partcile telescope which detects delayed gamma-rays from stopped 12Be nuclei, and MoNA which detects the prompt neutrons from the in-flight decay of 13Be into 12Be + n.

Figure 2: Experimental setup showing CAESAR (CsI) surrounding the charged partcile telescope which detects and stops 12Be nuclei from the in-flight decay of 13Be. This telescope was designed, developed, and tested by Prof. Nathan Frank of Augustana College with MRI funding from the NSF (Grant 1827840).

Summer Research

Undergraduate students from around the collaboration are busily at work running simulations, measuring cosmic rays, and testing different scintillating tile and SiPM layouts. They are learning all kinds of good skills from detector design to computing and making AI models fro simulations.