Akademik Veri Yönetim Sistemi
ADIM Fizik Günleri–I, Afyon Kocatepe Üniversitesi, Afyonkarahisar, Türkiye, 21 - 22 Mayıs 2010, ss.28, (Özet Bildiri)
Mass spectrometry (MS) is a versatile analytical technique
for identification and determination of atomic and/or molecular composition of
any sample. The MS principle consists of ionizing chemical compounds to
generate charged molecules or molecule fragments and measurement of their
mass-to-charge ratios. In general, mass spectrometer produces signal indicating
ion yields of several components of fragments as well as atomic ions. This
technique offers some advantages such as cost, simplicity, fast sampling and
simple signal processing giving whole mass spectrum over wide mass range. It is
especially suitable for measuring mass spectra of pulsed laser ionization
techniques. All ions generated by a short laser pulse can be used for
generating mass signal and this makes TOFMS a high sensetivity mass detection
device. Another important advantage of this system is no theoretically upper
mass limitation which is an essential feature for dedecting of large molecules.
We have designed and produced a homemade Time of Flight Mass
Spectrometer (TOFMS) system and its ion optics for the mass analysis of samples
in connection with a pulsed laser system. The recent developments on pulsed
laser technology have led researchers to have high photon intensity even with
nanosecond pulsed laser systems. The present work demonstrates the results
obtained using a TOF-MS investigation of some molecular systems connected to a
high power nanosecond laser systems. Wavelength and laser power dependences of
the fragmentation pattern of mass spectra obtained using 1064 nm, 532 nm and
355 nm have been presented with beam intensities up to 10^12 W/cm^2. The laser
system was connected to a hommade linear time-of-flight mass spectrometer.
Similar laser intensities for three wavelengths about 10^10-10^12 W/cm^2 have
been used and some differences on the process attending to the dissociative ionisation
dynamics have been presented in this work.