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Paul Northrup

Research Professor
Lead Scientist, Tender Energy Microspectroscopy Consortium

BA Biology, Dowling College, 1989
MS and Ph.D., Geosciences, Stony Brook University, 1992 and 1996
Postdoctoral Fellow, Bell Laboratories, 1996-97
Physicist, Bell Laboratories, 1998-2002
Environmental Scientist, Brookhaven National Laboratory, 2004-2009
TES Beamline Lead Scientist, BNL, 2013-2018
Research Faculty member at Stony Brook 2003-2004 and since 2009

My research is focused on applications of synchrotron X-ray fluorescence microscopy and microspectroscopy, especially of lighter elements Si, P, S, and Ca, in Earth, planetary and environmental sciences.  The Tender Energy Microspectroscopy Consortium operates a Partner User program at the TES Beamline 8-BM at the National Synchrotron Light Source II (NSLS-II, at Brookhaven National Lab.  TES is optimized for element-specific microcharacterization of heterogeneous natural and manufactured materials, in the “tender” energy range (2-5 keV, between “hard” >5 keV and “soft” <2 keV classifications of X-ray energy).  See first publication listed below.  The Consortium developed and provided instrumentation to build TES, with funding from NSF Earth Sciences, NASA LARS, and DOE Geosciences, in partnership with the NSLS-II facility.  

  1. 1.  The grain-scale distribution and chemical speciation of phosphorous in soils and sediments : P is an essential agricultural nutrient, but can also become a pollutant in ground- and surface-waters, causing harmful algae blooms and fishkills.  The grain-scale speciation controls whether the P is bioavailable to plants/crops or bound up in inert forms, or is so free as to readily wash away into waterways.  A new direction for this research is the potential release of bound P when coastal soils are inundated by rising sea levels.  This work includes collaborations with D. Sparks, Delaware Environmental Institute ( and D. Hesterberg, North Carolina State University.  
  1. 2.  Interplanetary dust particles and carbonaceous chondrite meteorites: IDPs and carbonaceous chondrites contain primitive material from the early solar system, and preserve information about processes from nebular condensation to planet formation.  These also contain carbon compounds and essential nutrients P and S, so their continuous supply may play an important role in the development of life on early Earth and potentially elsewhere.  Analysis of these materials is also groundwork for future analysis of materials returned from asteroid Bennu by the NASA OSIRIS REx mission.  This work includes collaboration with G. Flynn, SUNY Plattsburgh, and S. Wirick, FBE.  
  1. 3.  Martian and Lunar meteorites: rare meteorites found on Earth provide a glimpse at the geology and geochemistry of our celestial neighbors.  They provide clues about processes that shaped Mars and the Moon, and begin to address questions about why they differ from Earth, where water might be, and prospects for life.  
  1. 4.  Heterogeneous processes in new battery materials: although not Earth or planetary materials, battery electrodes are complex physically and chemically, and can be studied using the same tools to explore local molecular processes, even in-situ.  In particular, batteries utilizing less toxic and earth-abundant materials such as S can offer high efficiency and numerous environmental benefits.  
  1. 5.  I serve as a science advisor for the SPARK (Student Partnerships for Advanced Research and Knowledge) High School program involving several local schools, and provide training and opportunities for students to conduct their own experiments at TES and other NSLS-II beamlines.

Selected publications:   

P. Northrup, 2019. The TES Beamline (8-BM) at NSLS-II: tender-energy spatially resolved X-ray absorption spectroscopy and X-ray fluorescence imaging.  J. Synch. Rad., 26, 2064-2074. 

A. Gamble, P. Northrup, D. Sparks. 2019. Elucidation of Soil Phosphorus Speciation with Synchrotron-Based Microspectroscopic Techniques.  J. Environm. Qual.

E. Ingall, J. Brandes, J. Diaz, M. deJonge, D. Paterson, McNulty, C. Elliott, P. Northrup, 2011. Phosphorus K-edge XANES Spectroscopy of Mineral Standards, J. Synch. Rad., 18, 189–197.
database of spectra:

D Abdala, P Northrup, Y Arai, D Sparks.  2015.  Surface Loading Effects on Orthophosphate Surface Complexation at the Goethite/water Interface as Examined by Extended X-ray Absorption Fine Structure (EXAFS) Spectroscopy, J. Colloid Interface Sci., 437, 297-303.

D Abadala, P Northrup, E Cesar Vicentin, D Sparks, 2015.  Residence Time and pH Effects on the Bonding Configuration of Orthophosphate Surface Complexes at the Goethite/water Interface as Examined by Extended X-ray Absorption Fine Structure (EXAFS) Spectroscopy,  J. Colloid Interface Sci., 442, 15-21. 

A Leri, L Mayer, K Thornton, P Northrup, M Dunigan, K Ness, A Gellis, 2015.  A Marine Sink for Chlorine in Natural Organic Matter, Nature Geosci., 8, 620-624.

G Piccione, E T Rasbury, B Elliott, J R Kyle, S Jaret, A Acerbo, A Lanzirotti, P Northrup, K Wooton, R Parrish, 2019.  Vein Fluorite and Calcite U-Pb Dating Demonstrates Post 5 Ma REE Mobilization Associated with Rio Grande Rifting.   Geosphere, 15(6): 1958-1972.

G Flynn, S Wirick, P Northrup, 2019.  P Speciation in Large, Cluster Interplanetary Dust Particles.  50th Lunar and Planetary Science Conference, LPI No. 2132.

G Flynn, S Wirick, P Northrup.  Phosphorous Speciation in Primitive Interplanetary Dust: Clues to Grain Formation in the Solar Protoplanetary Disk.   82nd Annual Meeting of The Meteoritical Society, LPI No. 2157.

M Schoonen, J Hill, J Thieme, Y Chu, R Tappero, P Northrup, G Flynn, L Keller, K Chen-Wiegart, L Li, E Nazaretski, G Williams, S Wirick, H Yan, 2016.  Planetary Science Capabilities at National Synchrotron Light Source-II, Brookhaven National Laboratory, 47th Lunar and Planetary Science Conference, LPI Contribution No. 1903, p.2951.

N Vidavsky, J Kunitake, A Chiou, P Northrup, T Porri, L Ling, C Fischbach, L Estroff, 2018.  Studying Biomineralization Pathways in a 3D Culture Model of Breast Cancer Microcalcifications, Biomaterials, 179, 71-82.

P Northrup, A Leri, R Tappero, 2016.  Applications of “Tender” Energy (1-5 keV) X-ray Absorption Spectroscopy in Life Sciences,    Protein Peptide Lett., 23(3), 300-308. 

R. Reeder, G. Lamble, and P. Northrup, 1999. XAFS study of the coordination and local relaxation around Co2+, Zn2+, Pb2+, and Ba2+, trace elements in calcite, Am. Min., 84, 1049-1060.

Z Shadike, H-S Lee, C Tian, K Sun, L Song, E Hu, I Waluyo, A Hunt, S Ghose ,Y Hu, J Zhou, J Wang, P Northrup, S-M Bak and X-Q Yang.  2019.  Design and Synthesis of a New Organodisulfide and its Characterization as Cathode Material for High Performance Lithium Batteries.  Adv. En. Mat.
BNL Science Highlight:

T Wang, G-X Ren, Z Shadike, J-L Yue, M-H Cao, J-N Zhang, M-W Chen, X-Q Yang, S-M Bak, P Northrup, P Liu, X-S Liu, Z-W Fu.  2019.  Anionic redox reaction in layered NaCr2/3Ti1/3S2 through electron holes formation in addition to the dimerization of S-S.  Nature Comm.

X Yu, H Pan, Y Zhou, P Northrup, J Xiao, S Bak, M Liu, K Nam, X Yang, D Qu, J Liu, T Wu, X-Q Yang, 2015.  Direct Observation of the Redistribution of Sulfur and Polysufides in Li-S Batteries During First Cycle by In Situ X-ray Fluorescence Microscopy,  Adv. Energy Mater., 5(16), 1500072.

J Moon, P Kalb, L Milian, P Northrup.  2016.  Characterization of a sustainable sulfur polymer concrete using activated fillers.  Journal of Cement and Concrete Composites.

P Gregoire, A Engelbrektson, C Hubbard, Z Metlagel, R Csencsits, M Auer, M Conrad, J Thieme, P Northrup, J Coates, 2014.  Control of Sulfidogenesis Through Bio-oxidation of H2S Coupled to (per)chlorate Reduction, Environmental microbiology reports 6 (6), 558-564.

F Riquelme, P Northrup, J Ruvalcaba-Sil, V Stojanoff, D P Siddons, J Alvarado-Ortega, 2013.  Insights into restricted organic preservation in Chiapas amber using IR microimaging, PIXE/RBS and Sulfur K-edge XANES spectroscopy, Applied Physics A.

Mengqiang Zhu, Paul Northrup, Chenyang Shi, Simon Billinge, Donald Sparks, and Glenn Waychunas, 2013.  The Structure of Sulfate Adsorption Complexes on Ferrihydrite, Env. Sci. & Tech. Lett..

Y. Zhu, J. Zhang, L. Wu, A. Frenkel, J. Hanson, P. Northrup, W. Ku, 2007. Nanoscale Disorder in CaCu3Ti4O12: A New Route to Enhanced Dielectric Response, Phys. Rev. Lett., 99:037602.

P. Voyles, P. Citrin, D. Chadi, D. Muller, J. Grazul, P. Northrup, and H.-J. Gossmann, 2003. Evidence for a New Class of Defects in Highly n-doped Si: Donor-pair-vacancy-interstitials, Phys. Rev. Lett., 91

P. Citrin, P. Northrup, R. Birkhahn, A. Steckl, 2000. Local Structure and Bonding of Er in GaN: A Contrast with Er in Si, Appl. Phys. Lett., 76: 2865.

P. Citrin, D. Muller, H.-J. Gossmann, R. Vanfleet and P. Northrup, 1999. Geometric frustration of 2D dopants in silicon: surpassing electrical saturation, Phys. Rev. Lett. 18, 3234-3237.

T. Inoue, D. Weidner, P. Northrup, J. Parise, 1998. Elastic properties of hydrous ringwoodite (-phase) in Mg2SiO4, Earth and Planetary Sci. Lett. 160(1):107-113, 1998.

P Northrup and R Reeder, 1995.  Relationship between the structure and growth morphology of topaz [Al2SiO4(OH,F)2] using the periodic bond chain method, J. of Crystal Growth, 156, 433-442. 

P. Northrup and R. Reeder, 1994. Evidence for the importance of growth-surface structure to trace element incorporation in topaz, Am. Min., 79, 1167-1175. 

P. Northrup, K. Lienenweber, and J. Parise, 1994. The location of H in the high-pressure synthetic Al2SiO4(OH)2 topaz analogue, American Mineralogist, 79, 401-404.

P Northrup, J Parise, LK Cheng, LT Cheng and E McCarron, 1994.  High temperature single-crystal X-ray diffraction studies of potassium and (cesium, potassium) titanyl arsenates, Chem. Mat., 6, 434-440.

J Parise, D Corbin, L Abrams, P Northrup, J Rakovan, T M Nenoff, and G D Stucky, 1993.  Structural relationships between some BePO-, BeAsO- and AlSiO-RHO frameworks,  Zeolites, 14, 25-34.