Recent Publications: J. A. Northby

Negatively Charged Helium Microdroplets, (with C.Kim and T.Jiang), Physica B 197, 426 (1994)

Lifetime of an Electron on the Surface of Liquid Helium in the Presence of an Electric Field, (with C. Kim), Physica B 194-196, 1229 (1994)

Irradiation Effects of Ar Cluster Ions on Si Surfaces, (with G. Takaoka, G.Sugahara, R.E.Hummel, M.Sosnowski, I.Yamada), Materials Synthesis and Processing Using Ion Beams Symposium, Boston, MA, 29 Nov - 3 Dec, 1993 [Materials Research Society, 1994, p1005-1010]

Detachment Spectroscopy of Metastable Excitations in Helium Nanodroplets, (with C. Kim and S. Yurgenson), J. Low Temp. Phys. 101, 427, (1995)

Studies of Metastably Excited Helium Clusters. (with C. Kim, and T. Jiang), Surface Review and Letters, 3, 377, (1996)

Sputtering with Gas Cluster Ion Beams, (with J. Matsuo, M. Akizuki, G. H. Takaoka, and I. Yamada),Surface Review and Letters, 3, 1017, (1996)

Infrared Induced Electron Detachment from Negatively Charged Helium Nanodroplets (with C. Kim) Czech. Jour. Phys. 64,S1, 375 (1996)

Production of Cold Orthohelium in Counter Propagating Helium and Electron Beams (with S. Yurgenson) Czech. Jour. Phys. 64, S1, 543 (1996)

Spontaneous and infrared induced electron detachment from negatively charged helium nanodroplets (with C. Kim and S. Yurgenson), Zeitschrift fur Physik D, 40, 119 (1997)

Photodetachment of Metastable Helium Molecules from the Surface of Helium Nanodroplets,( with C. Kim, S. Yurgenson, and C.-C. Hu), Journal of Low Temperature Physics, 113, 1097 (1998)

Detachment of metastable helium molecules from helium nanodroplets. (with S. Yurgenson, C.-C. Hu, and C. Kim) Eur. Phys J. D, 9, 1 (1999)

Potential of an Ionic Impurity in a Large 4He Cluster, (with K. K. Lehmann), Molecular Physics, 97, 639(1999).

Spectroscopy of He2* floating on the liquid helium surface (with C.-C. Hu, and R. Petluri) Physica B284-288,107(2000)

Experimental studies of helium droplets, J. Chem. Phys. 115, 10065 (2001)

New optical instrument for sediment re-suspension measurements (2003)


  1. Method and Apparatus for Measuring Particle Motion Optically
    Patent No.:US 7,012,688 B2 (issue date: Mar. 14, 2006)
  2. Method and apparatus for measuring particle motion using scattered radiation
    Patent No.:US 7,453,569 B2 (issue date: Nov. 18, 2008)