Still, Cohen remains confident. Sometime in the next few years, if things progress as planned, he and his group will replace this machine with PFRC-3: a device twice as large that will hopefully allow them to achieve FRCs lasting as long as 10 seconds, with plasma temperatures on the order of 60 million K. And a few years after that, the plan calls for moving up to PFRC-4, an even larger machine designed to use live fusion fuel at temperatures of 600 million K. That fuel will be deuterium-helium- 3, which Cohen calls 'the Goldilocks approach' between deuterium -tritium and pB11. Unlike Helion, however, he plans to keep things simple and forgo any attempt to breed new helium- 3. Instead, Cohen will just live with the scarcity of helium-3, and focus on niche applications like spacecraft propulsion - an idea that emerged about a decade ago in discussions with Michael Paluszek, president of a space technology company, Princeton Satellite Systems, New Jersey, which is located just a few miles from Cohen's lab. Of course, it could be another 10 to 15 years before PFRC-based reactors are working reliably enough for a multi-year deep-space mission, assuming that they work at all. But then, much the same could be said about any of the alternative fusion designs - or for that matter, ITER. Taking the long view is pretty much a requirement for fusion energy research. 'If you want to do this really ambitious stuff in the 2030s,' Paluszek says, alluding to DFD missions, 'you need to be developing new technology now.' References

- 1. S. Thomas, Fusion-enabled Pluto orbiter and lander (NASA, 2016). https://www.nasa.gov/feature/fusion- enabled-pluto-orbiter-and-lander/.
- 2. H. Gota et al., Formation of hot, stable, long-lived field-reversed configuration plasmas on the C-2W device. Nucl. Fusion 59, 112009 (2019).
- 3. C. Brunkhorst, B. Berlinger, N. Ferraro, S. A. Cohen, The Princeton FRC Rotating-Magnetic-Field- Experiment RF System in 2007 IEEE 22nd Symposium on Fusion Engineering, (2007), pp. 1 - 4.

Wang, C., He, S., Zou, Y., Liu, J., Zhao, R., Yin, X., Zhang, H., Li, Y., 2020. Quantitative evaluation of in-situ bioremediation of compound pollution of oil and heavy metal in sediments from the Bohai Sea, China. Marine Pollution Bulletin 150, 110787.

http://www.sciencedirect.com/science/article/pii/S0025326X19309439 Owing to the semi-enclosed environment of the Bohai Sea, the ecological effects caused by an oil spill would be significant. A typical in- situ bioremediation engineering project for of oil-spilled marine sediments was performed in the Bohai Sea and a quantitative assessment of the ecological restoration was performed. The bioremediation efficiencies of n-alkane and PAHs in the sediment are 32.84 ± 21.66% and 50.42 ± 17.49% after 70 days of bioremediation, and 60.99 ± 10.14% and 68.01 ± 18.60% after 210 days, respectively. After 210 days of bioremediation, the degradation rates of two- to three ring PAHs and four-ring PAHs are 84.44 ± 23.03% and 26.62 ± 43.76%, respectively. In addition, the concentrations of the heavy metals first increased by 6.00% due to oil spill degradation and release, and then decreased by 72.60% with the degradation of oil caused by bioremediation or vertical migration. According to the continuous tracking monitoring, the composition of the microbial community in the restored area was similar to that in the control area and the clean area in Bohai Sea after 210 days of bioremediation. These results may provide some theoretical and scientific data to understand the degradation mechanism and assessing the ecological remediation efficiency for oil spills in open sea areas.

Wang, C., Wu, K., Scott, G.G., Akisanya, A.R., Gan, Q., Zhou, Y., 2020. A new method for pore structure quantification and pore network extraction from SEM images. Energy &Fuels 34, 82-94.

https://doi.org/10.1021/acs.energyfuels.9b02522 The structure of porous media is complex yet fundamental to the understanding of transport processes, including single and multiphase fluid flow. Pore network modeling is a valuable tool for studying these processes in many diverse porous media. This paper presents a new method of discretizing the pore space into