Sökning: "Atomic Physics"

Visar resultat 16 - 20 av 661 avhandlingar innehållade orden Atomic Physics.

1. 16. Optical Analysis of biological media - continuous wave diffuse spectroscopy

   Författare :Jan Sørensen Dam; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spatially resolved diffuse reflectance; in vitro diffuse spectroscopy; continuous wave techniques; Nuclear physics; multivariate data analysis.; Kärnfysik; Fysik; Physics; Medicin människa och djur ; Medicine human and vertebrates ; Monte Carlo simulations; light propagation models; multiple scattering; Tissue optics; tissue optical properties; Fysicumarkivet A:2000:Sörensen Dam;

   Sammanfattning : The main topic of this thesis is real-time quantification of relevant chromophores and light scattering elements in biological media. The presented methods and instrumentation are based on continuous wave (steady-state) optical measurements of (a) spatially-resolved diffuse reflectance from bulk media and (b) combined spatially-resolved and goniometric measurements of re-emitted light from thin samples. LÄS MER

3. 17. Laboratory studies of forbidden decay processes in stored ions

   Författare :Jonas Gurell; Sven Mannervik; Ahmed Al-Khalili; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic physics; Atomfysik; fysik; Physics;

   Sammanfattning : Measurements of atomic and ionic data has been an active research area since the beginning of spectroscopic studies. The experimental data deduced from thesestudies are of great interest for our understanding of fundamental as well as applied physics. LÄS MER

4. 18. Precision measurements on negative ions

   Författare :Moa Kristiansson; Henning T. Schmidt; Dag Hanstorp; Henning Zettergren; Christophe Blondel; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Negative ions; Atomic physics; Precision measurement; Electron affinity; Photodetachment; Physics; fysik;

   Sammanfattning : In this thesis, experiments with negative ions performed at the DESIREE facility are presented. DESIREE consists of two electrostatic storage rings operated at 13 K. The low temperature in combination with a low pressure allows for storage times of the negative ion beams to be up to several hours. LÄS MER

5. 19. New atomic masses related to fundamental physics measured with SMILETRAP

   Författare :Szilárd Nagy; Reinhold Schuch; Gunter Werth; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Penning Trap; mass spectrometry; Atomic physics; Atomfysik;

   Sammanfattning : This thesis describes the recent improvements of the SMILETRAP Penning trap mass spectrometer and a number of interesting high precision mass measurements, which have been performed using the improved apparatus, and are relevant in todays fundamental physics problems. The mass of the hydrogen-like 24,26Mg ions as well as the masses of the hydrogen- and lithium-like 40Ca ions are presented in this work that are indispensable input values when evaluating g-factor measurements of the bound electron. LÄS MER

7. 20. High Resolution Spectroscopy of Singly Charged Ions : Applications of Laser and Fourier Transform Techniques

   Författare :Jonas Gurell; Sven Mannervik; Richard Holt; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic physics; Atomfysik; fysik; Physics;

   Sammanfattning : This thesis presents measurements of fundamental properties of singly charged ionic systems including spectral wavelengths, lifetimes of excited states and branching fractions with the main focus on time resolved laser spectroscopy of stored ions providing lifetime measurements of metastable states. The results of these measurements have been used to determine energy levels and transition probabilities of the studied systems. LÄS MER