The methods devised by Gustav Mie in 1908 to explain the scattering of electromagnetic waves have a close analogy with quantum-mechanical models developed many years later to describe nuclear scattering. In particular, these models use either a complex index of refraction or a complex nuclear scattering potential to account for attenuation caused by non-elastic scattering. We briefly outline the historical development of these models and give examples illustrating the close analogy between them, their parameters, and the resulting scattering. In both models, the ratio of the incident wavelength to the object size, λ/D, can be determined from the scattering characteristics, allowing the extraction of microscopic particle dimensions. This close analogy allows students to simulate accelerator-based nuclear scattering experiments with table-top optical-scattering experiments.

There is an ongoing challenge with STEM education: making physics, math, and science, in general, interesting, understandable, and retentive for college science and non-science majors, K-12 students, and the public. If not imparting detailed knowledge, at least one would like to introduce important concepts that will be remembered, appreciated, and hopefully would be pursued in more detail by audience members. One solution: as noted by Socrates, “Wisdom begins in wonder.” Indeed, magic as a form of wonderment dates back to Socrates and even earlier. One of the first magic books, The Discoverie of Witchcraft by Reginald Scot, was published in 1584, predating publication of many science texts. In this paper the author, based on recent research, advocates using special forms of magic to both amaze and teach, and in particular to illustrate the wonders of modern physics, i.e., Nature’s magic, but with connections also to classical physics.

We characterized the light output response of a new 140 cm3 stilbene-d12 crystal up to 14.1 MeV neutron energies using a coincidence neutron scattering system. We also characterized its light output response to alpha particles in the 5 to 6~MeV energy range. The excellent PSD capability of the stilbene-d$_{12}$ detector allowed us to select light pulses produced by particles of increasing ionization density, namely electrons, protons, deuterium-ions, and alpha particles. The measured fast decay component of the light pulses is increasingly quenched as the ionization density of the particle in the crystal increases. Consistently with this finding, the Birks' quenching parameter of alpha particles is approximately 8.5 times larger compared to the quenching of deuterium ions, produced by neutron scattering interactions. The reported experimental characterization will allow high-fidelity modeling of the detector enabling its application for fast-neutron detection and spectroscopy in nuclear physics, radiation protection, nuclear security, and non-proliferation.

A new precision half-life measurement of 13N has been conducted using the TwinSol n-counting station at the University of Notre Dame. The measured value of t1/2new = 597.05(19) s differs from the previous world value by about 2.8 sigma. An evaluation of the 13N half-life results in a tworld 1/2 = 597.19(22) s. Updated standard model predictions for the Fermi to Gamow-Teller mixing ratio rho and its associated correlation parameters have been calculated using the new 13N world half-life in preparation for a future measurement of the mixing ratio. Finally, an ab initio no-core configuration interaction (NCCI) calculation for the B(GT) of this decay, carried out using the Daejeon16 interaction, has been performed, revealing the need for higher-order chiral corrections.

We have experimentally characterized the light-output response of a deuterated trans-stilbene (stilbene-d12) crystal to quasi-monoenergetic neutrons in the 0.8 to 4.4 MeV energy range. These data allowed us to perform neutron spectroscopy measurements of a DT 14.1 MeV source and a PuBe-239 source by unfolding the impinging neutron spectrum from the measured light-output response. The stilbene-d12 outperforms a H1-stilbene of similar size when comparing the shape of the unfolded spectra and the reference ones. These results confirm the viability of non-hygroscopic stilbene-d12 crystal for direct neutron spectroscopy without need for time-of-flight measurements. This capability makes stilbene-d12 a well suited detector for fast-neutron spectroscopy in many applications including nuclear reaction studies, radiation protection, nuclear non-proliferation, and space travel.

We have characterized the neutron and alpha light output response, and anisotropy of a 140 cm 3 deuterated trans-stilbene (stilbene-d 12 ) crystal of approximately. The neutron light output response was characterized in the 0.5 to 14.1 MeV energy range using a coincidence neutron scattering system, based on a D-T source. The light output response to alpha particles was characterized in the 5 to 6 MeV range using multiple alpha sources. The light output response to the two types of particles is explained well by a semi-empirical functional form based on the Birks’ light-output model. The anisotropy of the stilbene-d 12 was characterized from 0° to 360° in response to 14.1 MeV neutrons. The stilbene-d 12 has a larger light emission when the beam direction is parallel to the b axis in the a-b crystal plane. The crystal used in this work was grown at Lawrence Livermore National Laboratory using a solution growth method.

The half-life of O-15 was measured using the beta-Counting Station at the University of Notre Dame's Nuclear Science Laboratory. Our new result, t(1/2) = 122.308(49) s, is the most precise determination to date for O-15, and improves the world average by a factor of 4, yielding t(1/2)(world) 122.27(6) s. This more precise value will be important for future determinations of V-ud using superallowed T = 1/2 mirror transitions.

The Li-7(gamma, t)(4) He ground state cross section was measured for the first time using monoenergetic gamma rays with energies between 4.4 and 10 MeV at the High Intensity Gamma-ray Source. The reaction is important for the primordial Li problem and for testing our understanding of the mirror a-capture reactions H-3(alpha, gamma)(7) Li and He-3(alpha, gamma)(7) Be. Although over the last 30 years most measurements of the H-3(alpha, gamma)(7) Li reaction have concentrated in an energy range below E gamma = 3.65 MeV, measurements at higher energies could potentially restrict the extrapolation to astrophysically important energies. The experimental arrangement for measuring the Li-7(gamma, t)He-4 reaction included a large-area silicon detector array and several beam characterization instruments. The experimental astrophysical S factor of H-3(alpha, gamma) calculated from the present data was fitted using the R-matrix formalism. The results are in disagreement with previous experimental measurements in the same energy range but the extrapolated S factor agrees with the potential model calculation and lower energy experimental data.

A new precision half-life measurement of P-29 was conducted using the TwinSol beta-counting station at the University of Notre Dame Nuclear Science Laboratory. The resulting value of t(1/2)(new) = 4.1055(44) s is the most precise P-29 half-life measurement to date. Utilizing this measurement and reevaluating the world data leads to a new world average of t(1/2)(world) = 4.1031(58) s, which improves the Birge ratio from 3.11 to 1.45 and is 2.3 times more precise than the previous world value. The new Cabibbo-Kobayashi-Maskawa matrix element V-ud for P-29 shifts closer into agreement with the superallowed pure Fermi value. The uncertainty in the mixed transition value of V-ud, however, is still dominated by the Fermi to Gamow-Teller mixing ratio rho. Using the new world half-life and assuming the validity of the standard model, a new predicted value for rho and its associated correlation parameters have been evaluated in order to guide future determination of rho.

Precise antineutrino measurements are very sensitive to proper background characterization. We present an improved measurement of the C-13(alpha, n)O-16 reaction cross section which constitutes significant background for large (nu) over bar detectors. We greatly improve the precision and accuracy by utilizing a setup that is sensitive to the neutron energies while making measurements of the excited state transitions via secondary gamma-ray detection. Our results shows a 54% reduction in the background contributions from the O-16(3(-), 6.13 MeV) state used in the KamLAND analysis.

There is a new generation of high-speed programmable pulse digitizers available now from several vendors at modest cost. These digitizers in tandem with on-board or post-processing software combine to produce a Software-Defined Electronics (SDE) system that can be effectively used in several advanced physics teaching lab experiments. In particular, as we will demonstrate, they are particularly well suited for nuclear-physics related experiments, often replacing many analog electronics modules. Appropriate on-board SDE can generate full or partial integrals of the pulses, pulse-shape characterization (PSD) data, coincidence signal indication, fast timing, or other information. Likewise, external PC-based SDE post-processing software can readily be developed and applied by undergraduate students or instructors using one of several different software languages available: matlab, python, LabVIEW, root, basic, etc. As demonstrated here, an SDE-based system is a cost-effective substitute for many dedicated NIM or CAMAC electronics modules as this requires only a single digitizer module and a computer. A single digitizer with SDE is easily adapted for use in many different experiments. Applications of various high- and low-speed digitizers with SDE for many other types of physics teaching lab experiments will also be discussed.

Helical spectrometers, such as the HELIOS device at Argonne National Laboratory, have proven to be a powerful tool for the study of nuclear spectroscopy (Lighthall, 2010). However, due to the expense in procuring a large bohr solenoid, relatively few of these devices exist. However, at the University of Notre Dame, TwinSol, is composed of two such magnets. The availability of intense light-ion beams from the Notre Dame Nuclear Science Laboratory (NSL) in combination with a large-bore superconducting solenoids provides an excellent opportunity to develop a new solenoid spectrometer at the University of Notre Dame, one optimized for measurements in normal kinematics.

We report the first evidence of breakup dominance at deep sub-barrier energies for the proton halo nucleus B-8 on a heavy target. Angular distribution measurements of the B-8 breakup fragment, Be-7, on lead were performed at the TwinSol facility of the University of Notre Dame at a beam energy of 30 MeV, 58% of the Coulomb barrier and corresponding to a distance of closest approach of 20.5 fm. The Be-7 yield was observed in two double sided silicon strip detector telescopes symmetrical to the radioactive beam and normalized using the B-8 Rutherford scattering. The results are in excellent agreement with continuum discretized coupled channel calculations with a total breakup cross section (326 +/- 84) mb. This is found to exhaust all of the total reaction cross section for the system B-8 + (208)pb, possibly prohibiting a fusion enhancement. This finding is expected to give more insight to the puzzle of fusion suppression at deep sub-barrier energies with possible major consequences on nuclear astrophysics.

Much effort has been made to understand the origins of F-18 in novae. Due to its relatively long half-life (similar to 2 hours), F-18 can survive until the nova envelope is transparent, and therefore can provide a sensitive diagnostic of nova nucleosynthesis. It is likely produced through the beta decay of Ne-18, which is itself produced (primarily) through the F-17(p,gamma) reaction. Understanding the direct capture contribution to the F-17(p,gamma) reaction is important to accurately calculate it. As such, the proton spectroscopic strengths of low-lying states in Ne-18 are needed. At the University of Notre Dame a measurement of the F-17(d,n) reaction has been performed using a beam produced by the TwinSol low energy radioactive beam facility. Preliminary data analysis is presented.

We report a new precision half-life measurement of F-20, performed using the beta-counting station of the University of Notre Dame's Nuclear Science Laboratory. The measured half-life of 11.0160(41)(stat) (155)(sys) s resulting from this work will help resolve the longstanding discrepancy between two earlier sets of high-precision half-life measurements.

Background: The precise determination of the Ft value in T=1/2 mixed mirror decays is an important avenue for testing the standard model of the electroweak interaction through the determination of Vud in nuclear β decays. C11 is an interesting case, as its low mass and small QEC value make it particularly sensitive to violations of the conserved vector current hypothesis. The present dominant source of uncertainty in the C11Ft value is the half-life. Purpose: A high-precision measurement of the C11 half-life was performed, and a new world average half-life was calculated. Method: C11 was created by transfer reactions and separated using the TwinSol facility at the Nuclear Science Laboratory at the University of Notre Dame. It was then implanted into a tantalum foil, and β counting was used to determine the half-life. Results: The new half-life, t1/2=1220.27(26) s, is consistent with the previous values but significantly more precise. A new world average was calculated, t1/2world=1220.41(32) s, and a new estimate for the Gamow-Teller to Fermi mixing ratio ρ is presented along with standard model correlation parameters. Conclusions: The new C11 world average half-life allows the calculation of a Ftmirror value that is now the most precise value for all superallowed mixed mirror transitions. This gives a strong impetus for an experimental determination of ρ, to allow for the determination of Vud from this decay.