$U(r)=-\frac{W_0r_0}{r}\exp\left(-\frac{r}{r_0}\right)$
$\frac{E_{bind}}{c^2}=a_1A-a_2A^{2/3}-a_3\frac{Z(Z-1)}{A^{1/3}}-a_4\frac{(N-Z)^2}{A}+\epsilon a_5A^{-3/4}$
$R=R_0\left[1+\sum_{lm}a_{lm}Y_l^m(\theta,\varphi)\right]$

# Matthew Mumpower

Postdoctoral Research Fellow @ Los Alamos National Lab

I'm a theoretical physicist working at Los Alamos National Lab. I received my PhD at North Carolina State University under the direction of Gail McLaughlin. At the University of Notre Dame I worked under the direction of Ani Aprahamian and Rebecca Surman. My research interests are in nuclear structure and reaction mechanisms. The study of these models has a wide range of applicability from nuclear medicine, to stockpile stewardship and even the cosmos.

At Los Alamos we seek to solve national security challenges through scientific excellence. This means we not only apply our models to the task at hand, but we seek to push them to the limits by probing the edges of our knowledge with basic science research. One way I contribute to basic science research at the lab is to study the applicability of LANL nuclear models to nucleosynthesis. Nucleosynthesis is the study of the processes by which chemical elements are synthesized in cosmic environments. In other words, this part of my research focuses on how the elements on the periodic table were created. This field is extremely challenging and also very rewarding with many real world applications. Check out the research section of this website for more information.

I firmly believe that practicing in scientific inquiry is both empowering and a necessary requirement for success in today's world. You can learn more about my teaching efforts in the teach section of this website.

Outside of Physics I enjoy keeping up with latest technology trends and coming up with unique solutions to challenging problems. For more about my entrepreneurial endeavours check out Solace Development Group. In my free time I try to stay in shape by playing racquetball. If you are interested in a game, shoot me an e-mail.

## Latest Paper (June 11th 2017)

### Estimation of M1 scissors mode strength for deformed nuclei in the medium to heavy mass region by statistical Hauser-Feshbach model calculations

Radiative neutron capture is an important nuclear reaction whose accurate description is needed for many applications ranging from nuclear technology to nuclear astrophysics. The description of such a process relies on the Hauser-Feshbach theory which requires the nuclear optical potential, level density and $\gamma$-strength function as model inputs. It has recently been suggested that the M1 scissors mode...

# Select Papers

#### Fission Barriers at the End of the Chart of Nuclides

P. Möller, A. J. Sierk, T. Ichikawa, A. Iwamoto, M. Mumpower
Phys. Rev C 91 024310 - Published February 12th 2015
We present calculated fission-barrier heights for 5239 nuclides, for all nuclei between the proton and neutron drip lines with $171 \le A \le 330$. The barriers are calculated in the macroscopic-microscopic finite-range liquid-drop model with a 2002 set of macroscopic-model parameters. The saddle-point energies are determined from potential-energy surfaces based on more than five million different shapes, defined by five deformation parameters in the three-quadratic-surface shape parameterization: elongation, neck diameter, left-fragment spheroidal deformation, right-fragment spheroidal deformation, and nascent-fragment mass asymmetry. The energy of the ground state is determined by calculating the lowest-energy configuration in both the Nilsson perturbed-spheroid ($\epsilon$) and in the spherical-harmonic ($\beta$) parameterizations. The lower of the two results (correcting for zero-point motion) is defined as the ground-state energy. The effect of axial asymmetry on the inner barrier peak is calculated in the $\epsilon-\gamma$ parameterization. We have earlier benchmarked our calculated barrier heights to experimentally extracted barrier parameters and found average agreement to about one MeV for known data across the nuclear chart. Here we do additional benchmarks and investigate the qualitative, and when possible, quantitative agreement and/or consistency...

#### Sensitivity studies for a main $r$ process: $\beta$-decay rates

M. Mumpower, J. Cass, G. Passucci, R. Surman, A. Aprahamian
AIP Advances 4, 041009 - Published February 25th 2014
The pattern of isotopic abundances produced in rapid neutron capture, or $r$-process, nucleosynthesis is sensitive to the nuclear physics properties of thousands of unstable neutron-rich nuclear species that participate in the process. It has long been recognized that the some of the most influential pieces of nuclear data for $r$-process simulations are $\beta$-decay lifetimes. In light of experimental advances that have pushed measurement capabilities closer to the classic $r$-process path, we revisit the role of individual $\beta$-decay rates in the $r$ process. We perform $\beta$-decay rate sensitivity studies for a main ($A>120$) $r$ process in a range of potential astrophysical scenarios. We study the influence of individual rates during $(n,\gamma)$-$(\gamma,n)$ equilibrium and during the post-equilibrium phase where material moves back toward stability. We confirm the widely accepted view that the most important lifetimes are those of nuclei along the $r$-process path for each astrophysical scenario considered. However, we find in addition that individual $\beta$-decay rates continue to shape the final abundance pattern through the post-equilibrium phase, for as long as neutron capture competes with $\beta$ decay. Many of the lifetimes important for this phase of...

## Racquetball

In my free time I play competitive racquetball. I was one of the top ranked players of the North Carolina State University Racquetball Club from 2008 to 2012. I designed their website which you can find an image of right here.