Nuclear Experimentation Dr. Stephanie Lyons

The day so far: NOW: Looking ahead: Basics of nuclear physics Smashing nuclei Toured NSCL Lectures Laboratory experiments NOW: Basics of nuclear physics Discuss what research looks like Looking ahead:

High Z Superheavies Proton Rich Neutron Rich Why doesn’t the valley of stability follow N=Z line? Proton Rich Neutron Rich protons, Z neutrons, N Courtesy of A. Spyrou

Nuclear Nomenclature Element Isotope Isotone Isobar protons, Z neutrons, N

What would we like to know? General Properties: Mass Life-time Decay Mode protons, Z neutrons, N

Calculate Mass Essentials and Conversions: mp = 1.00727647 amu mn = 1.00866490 amu 1 amu = 1.66054 x 10-27 kg 1 MeV = 1.602 x 10-13 Joules + 42He 2p 2n

BINDING BLOCKS Essentials and Conversions: mp = 1.00727647 amu GOAL: Build a section of the nuclear chart based on binding energy with Legos. As a group calculate the binding energies for your isobars. Compare to the tile board: If Correct you can build your isotopes If Not, go back to the calculations to determine the error and try again. Continue building the chart Discuss Essentials and Conversions: mp = 1.00727647 amu mn = 1.00866490 amu 1 amu = 1.66054 x 10-27 kg 1 MeV = 1.602 x 10-13 Joules

How else can we use nuclear binding energy?

What does this tell us about how matter is created and transformed? pp-chain

Z N Stellar burning pp chain rp / νp process p process s process r process 56Fe Stellar burning pp chain N

How can we best answer questions about how nuclei are created?

Scientific Method Identify question/problem Can I design an experiment to learn something new? Propose experiment [NSCL Proposal Advisory Committee accepts ~50% of proposed experiments] Design, build new equipment, schedule experiment Run experiment (5-10 days, running 24/7) Data analysis (~3 months – 2 years) Compare to theory (if possible) Publish results

How are elements heavier than iron formed? What questions can we ask about this process? Question: How do certain nuclei go through beta-decay?

Scientific Method Identify question/problem Can I design an experiment to learn something new? Propose experiment [NSCL Proposal Advisory Committee accepts ~50% of proposed experiments] Design, build new equipment, schedule experiment Run experiment (5-10 days, running 24/7) Data analysis (~3 months – 2 years) Compare to theory (if possible) Publish results

Designing an experiment: What are requirements to be able to accurately answer my science question Let’s make a list Is there a laboratory that best suits the needs of my experiment YES: Proposal! – if accepted we can schedule NO: What development needs to occur to be able to do this? Design experiment to best extract all of the required information for your science question What data are needed?

Scientific Method Identify question/problem Can I design an experiment to learn something new? Propose experiment [NSCL Proposal Advisory Committee accepts ~50% of proposed experiments] Design, build new equipment, schedule experiment Run experiment (5-10 days, running 24/7) Data analysis (~3 months – 2 years) Compare to theory (if possible) Publish results

Experimental Set-up Isotopes of interest delivered to experimental end station SuN Detector for Particle Identification Implantation and B-decay detector

Data that was collected: Particle entering end station Implantation energy and time Subsequent beta-decay and time De-excitation of daughter nucleus

Scientific Method Identify question/problem Can I design an experiment to learn something new? Propose experiment [NSCL Proposal Advisory Committee accepts ~50% of proposed experiments] Design, build new equipment, schedule experiment Run experiment (5-10 days, running 24/7) Data analysis (~3 months – 2 years) Compare to theory (if possible) Publish results

Data Analysis and Results: t ½= 213 ± 18 ms t ½(lit.)= 227 ms Time (ms) Counts 69Co t ½= 85 ± 10 ms t ½(lit.)= 80 ms Counts 71Co Co Time (ms)

Final results demonstrate improvement in our knowledge 1821.2 1517.6 915.3 321 (3.5s) 0.0 0.0 (227 ms) 69Co 69Ni Qβ= 9.81 MeV 69Co decay 71Co decay

Summary Nuclear binding energy How it’s calculated What it can tell us How real research is performed Still use scientific method Went through the process for an experiment recently performed at the NSCL