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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:2
UID:UW-Physics-Event-8513
DTSTART:20240209T213000Z
DTEND:20240209T230000Z
DTSTAMP:20260413T223358Z
LAST-MODIFIED:20240122T152656Z
LOCATION:Chamberlin 2241
SUMMARY:Retrieving images from tarnished 19th century daguerreotypes u
 sing X-ray fluorescence imaging with an X-ray micro beam with tunable 
 energy\, Physics Department Colloquium\, Tsun-Kong (T.K.) Sham\, Weste
 rn University\, Ontario
DESCRIPTION:An overview of the recent success of using X ray fluoresce
 nce (XRF) imaging excited with a tunable X-ray microbeam from synchrot
 ron light sources for the recovery of damaged and obstructed 19th cent
 ury daguerreotype will be presented. [1\, 2] Daguerreotype is the firs
 t commercial photography in human history (early 1800’s) produced on
  a polished\, silver coated copper plate. We show that high quality im
 ages can always be retrieved from tarnished plates using Hg L XRF a
 s long as the bulk of the image particles and their distribution remai
 n intact. This technique overcomes the challenges of conventional cons
 ervation methods which are often unable to bright the image back to li
 fe. We also report results from using tunable tender X-rays (2 - 7 keV
 ) to image in high vacuum at energy above the Ag L-edge and the Hg M-e
 dge\, extracting images using Ag L and Hg M\, respectively among
  others (e.g.\, S to track corrosion). Images obtained with the surfac
 e sensitive total electron yield (TEY) and the bulk sensitive fluoresc
 ence yield (FLY) as well as corresponding micro-XANES are noted. Flux 
 tolerance to high intensity X-beam is also explored. These results and
  their implications for cultural heritage and other cultural heritage 
 research and prospects of the technique at fourth generation light sou
 rces will be discussed.
\n
\n1.	Kozachuk\, M.S.\; Sham\, T.K.\; Martin
 \, R.R.\; Nelson\, A.J.\; Coulthard\, I.\; McElhone\, J.P. Recovery of
  Degraded-Beyond Recognition 19th Century Daguerreotypes with Rapid Hi
 gh Dynamic Range Elemental X-ray Fluorescence Imaging of Mercury L Emi
 ssion. Sci. Rep. 2018\, 8\, 1. https://doi.org/10.1038/s41598-018-2771
 4-5
\n2.	Stark\, A\; Filice\, F.\; Noël\, J.J.\; Martin\, R.R.\; Sham
  T.K.\; Finfrock\, Y.Z.\; Heald\, S.M. Retrieving Tarnished Daguerreot
 ype Content Using X-ray Fluorescence Imaging-Recent Observations on th
 e Effect of Chemical and Electrochemical Cleaning Methods\, Herit. Sci
 . 2021\, 4\, 1605-1615 https://doi.org/10.3390/heritage4030089
\n
\n*R
 esearch conducted at Western University is supported by NSERC\, CFI\, 
 CRC of Canada and OIT of Ontario and Western University
\n
URL:https://www.physics.wisc.edu/events/?id=8513
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