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

# Matthew Mumpower

Staff Scientist @ 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 (September 3rd 2018)

### FRIB and the GW170817 kilonova

In July 2018 an FRIB Theory Alliance program was held on the implications of GW170817 and its associated kilonova for r-process nucleosynthesis. Topics of discussion included the astrophysical and nuclear physics uncertainties in the interpretation of the GW170817 kilonova, what we can learn about the astrophysical site or sites of the r process from this event, and the advances...

# Select Papers

#### Neutron-capture rates for explosive nucleosynthesis: the case of $^{68}$Ni$(n,\gamma)^{69}$Ni

A. Spyrou et al.
J. Phys. G 44 4 044002 - Published February 23rd 2017
Neutron-capture reactions play an important role in heavy element nucleosynthesis, since they are the driving force for the two processes that create the vast majority of the heavy elements. When a neutron capture occurs on a short-lived nucleus, it is extremely challenging to study the reaction directly and therefore the use of indirect techniques is essential. The present work reports on such an indirect measurement that provides strong constraints on the $^{68}$Ni(n,$\gamma$)$^{69}$Ni reaction rate. This is done by populating the compound nucleus $^{69}$Ni via the $\beta$ decay of $^{69}$Co and measuring the $\gamma$-ray deexcitation of excited states in $^{69}$Ni. The $\beta$-Oslo method was used to extract the $\gamma$-ray strength function and the nuclear level density. In addition the half-life of $^{69}$Co was extracted and found to be in agreement with previous literature values. Before the present results, the $^{68}$Ni(n,$\gamma$)$^{69}$Ni reaction was unconstrained and the purely theoretical reaction rate was highly uncertain. The new uncertainty on the reaction rate based on the present experiment (variation between upper and lower limit) is approximately a factor of 3. The commonly used reaction libraries...

#### Sensitivity studies for a weak $r$ process: neutron capture rates

R. Surman, M. Mumpower, R. Sinclair, K. Jones, W. Hix, G. C. McLaughlin
AIP Advances 4, 041008 - Published February 23rd 2014
Rapid neutron capture nucleosynthesis involves thousands of nuclear species far from stability, whose nuclear properties need to be understood in order to accurately predict nucleosynthetic outcomes. Recently sensitivity studies have provided a deeper understanding into how the $r$ process proceeds and have identified pieces of nuclear data of interest recommended for further experimental or theoretical study. A key result of these studies has been to point out the importance of individual neutron capture rates in setting the final $r$-process abundance pattern for a 'main' ($A\sim 130$ peak and above) $r$ process. Here we examine neutron capture in the context of a 'weak' $r$ process that forms primarily the $A\sim 80$ $r$-process abundance peak. We identify the astrophysical conditions required to produce this peak region through weak $r$-processing and point out the neutron capture rates that most strongly influence the final abundance...

## 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.