Cryogenic 35GHz pulse ENDOR probehead accommodating large sample sizes: Performance and applications.
The construction and performance of a cryogenic 35GHz pulse electron nuclear double resonance (ENDOR) probehead for large samples is presented. The resonator is based on a rectangular TE(102) cavity in which the radio frequency (rf) B(2)-field is generated by a two turn saddle ENDOR coil crossing the resonator along the sample axis with minimal distance to the sample tube. An rf power efficiency factor is used to define the B(2)-field strength per square-root of the transmitted rf power over the frequency range 2-180MHz. The distributions of the microwave B(1)- and E(1)-field, and the rf B(2)-field are investigated by electromagnetic field calculations. All dielectrics, the sample tube, and coupling elements are included in the calculations. The application range of the probehead and the advantages of using large sample sizes are demonstrated and discussed on a number of paramagnetic samples containing transition metal ions.
Tschaggelar
René
R
Laboratory of Physical Chemistry, ETH Zurich, Zürich CH-8093, Switzerland.
Kasumaj
Besnik
B
Santangelo
Maria Grazia
MG
Forrer
Jörg
J
Leger
Patrik
P
Dube
Henry
H
Diederich
François
F
Harmer
Jeffrey
J
Schuhmann
Rolf
R
García-Rubio
Inés
I
Jeschke
Gunnar
G
D000465:Algorithms; D003031:Coal / Q000032:analysis; D003080:Cold Temperature; D003198:Computer Simulation; D004574:Electromagnetic Fields; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation*; D005998:Glycine / Q000737:chemistry; D006371:Helium; D007211:Indoles / Q000737:chemistry; D054833:Isoindoles; D008667:Metalloproteins / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry
D003031:Coal; D007211:Indoles; D054833:Isoindoles; D008667:Metalloproteins; D009942:Organometallic Compounds; D011166:Porphyrins; D006371:Helium; C018493:cupric glycinate; D005998:Glycine; C013647:phthalocyanine