BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Helium Spin-Echo: A Flexible Tool for Studying Nanoscale Processes
  at Surfaces - Dr Andrew Jardine\, University of Cambridge 
DTSTART:20181116T143000Z
DTEND:20181116T153000Z
UID:TALK114847@talks.cam.ac.uk
CONTACT:Kayleigh Dunn
DESCRIPTION:Many fundamental and technologically relevant surface processe
 s take place over Angstrom to nanometre length scales and picosecond to na
 nosecond timescales. However\, the combination is extremely challenging to
  study experimentally\; microscopy cannot achieve the necessary time-resol
 ution\, whereas spectroscopic experiments generally have poor spatial reso
 lution. In this talk\, I will introduce the Helium Spin-Echo technique\, a
  method pioneered at the Cavendish\, which has enabled the regime to be ac
 cessed experimentally for the first time.  The technique involves scatteri
 ng helium atoms while simultaneously using nuclear spin-polarisation of th
 e atoms to split and recombine the helium wavepackets\, giving a reciproca
 l-space surface-correlation measurement\, with sensitivity over the picose
 cond range.\nHelium Spin-Echo measurements can be applied to a wide range 
 of surface processes and in many cases have revolutionised our understandi
 ng of underlying physical phenomena.  I will discuss a series of examples 
 from recent experiments including the rates and mechanisms of nanoscale di
 ffusion\, the behaviour arising from complex extended molecules compared t
 o point particles\, determination of interaction potentials and rate limit
 ing energy barriers\, the transition to quantum transport\, and energy exc
 hange rates / vibrational lifetimes giving subsequent insights into fricti
 on on the nanoscale.\n
LOCATION:Small Lecture Theatre\, Bragg Building\, Cavendish Laboratory (Ph
 ysics Department)
END:VEVENT
END:VCALENDAR