The Electron Injection Function and Energy‐dependent Delays in Thick‐Target Hard X‐Rays

1998 ◽  
Vol 509 (2) ◽  
pp. 911-917 ◽  
Author(s):  
John C. Brown ◽  
Andrew J. Conway ◽  
Markus J. Aschwanden
Author(s):  
M. Khaliquzzaman ◽  
S.T. Lam ◽  
T. Otsubo ◽  
A.H. Hussain ◽  
L.G. Stephens-Newsham

1994 ◽  
Vol 375 ◽  
Author(s):  
G. D. Waddill ◽  
J. G. Tobin ◽  
X. Guo ◽  
S. Y. Tong

AbstractThe first structural determination with spin-polarized, energy-dependent photoelectron diffraction using circularly-polarized x-rays is reported for Fe films on Cu(001). Circularly-polarized x-rays produce spin-polarized photoelectrons from the Fe 2p doublet, and intensity asymmetries in the 2p3/2 level are observed. Fully spin-specific multiple scattering calculations reproduce the experimentally-determined energy and angular dependences. A new analytical procedure which focuses upon intensity variations due to spin-dependent diffraction is introduced. A sensitivity to local geometric and magnetic structure is demonstrated.


1970 ◽  
Vol 9 (11) ◽  
pp. 1297-1305 ◽  
Author(s):  
Kunihiro Shima ◽  
Masakatsu Sakisaka ◽  
Masayuki Kokado ◽  
Takehisa Yamamoto ◽  
Isao Makino
Keyword(s):  

1996 ◽  
Vol 06 (01n02) ◽  
pp. 31-37 ◽  
Author(s):  
T.C. Chu ◽  
K. Ishii ◽  
M. Kikuchi ◽  
K. Murozono ◽  
C.C. Hsu ◽  
...  

We measured continuum x-rays from an aluminium target bombarded with 60 keV- and 80 keV- proton beams. On the basis of the PWBA theory, we calculated the thick target yields of atomic bremsstrahlung and nuclear bremsstrahlung produced in very low energy ion-atom collisions and compared with the experiment. The present theory predicts that the main component of continuum x-rays produced in such low energy ion-atom collisions is the nuclear bremsstrahlung. The theory presents the yields of continuum x-rays about 5 times larger than the experimental ones, however, reproduces well the spectral shape.


2011 ◽  
Vol 21 (2) ◽  
pp. 169
Author(s):  
Nguyen Ngoc Duy ◽  
Le Hong Khiem

The stellar reaction 22Mg(α,p)25Al plays an important role for understanding the nucleosynthesis of stars. It has never investigated yet. We are planning to study this reaction in environment of X-rays burst with temperature T9 = 1÷3 GK using invert kinematics and thick target method. This paper shows a design for direct investigation of this reaction by simulation method. This design is necessary for experimental setup and for confirmation of the feasibility of the experiment.


2020 ◽  
Author(s):  
Avupati Venkata Surya Satyanarayana ◽  
Mokka Jagannadha Rao ◽  
Byreddy Seetharami Reddy

Abstract. The majority of PIXE analytical study on geosciences has used 3 MeV proton beams for excitation and these studies generally uses the K-X-rays for low Z elements and L-X-rays for high Z elements. The present study of resulting spectra of metamorphic high grade rocks like charnockite can require striping techniques to resolve interference problems between low and high Z elements on the applications of light energy-PIXE using Si (Li) detector. In all forms of X-ray analysis, including thick-target light energy-PIXE, the X-ray signal is a dependent of the ionization cross section and for low-energy protons, the cross section is high for the K shells of light elements and the L shells of heavy elements in charnockite rock providing sufficient fluorescent yield for analytical purposes. For Z > 55, 3 MeV protons cannot ionize K-shell electrons and analysis depends on the use of L-X-ray lines in charnockite rock. Such L-X-ray spectra are complicated and can be affected by interferences K-X-rays from low Z elements. The low Z elements present in the charnockite were identified by previous complementary analytical techniques, but not identified in this study due to the above PIXE experiment limitations, and also particularly due to the dimensions of Si (Li) detector because of low energy K-X-rays of the elements absorbed by the detector window. Both interferences complexity and detector efficiency can lead to difficulties and ambiguity in the interpretation of spectra of low Z charnockite composition, a problem that is exacerbated by uncertainty in relative K-X-ray line intensities of low Z elements. From this investigation, the light energy-PIXE is ideal for the analysis of low Z 


1998 ◽  
Vol 11 (1) ◽  
pp. 385-385
Author(s):  
Y. Kim ◽  
K. Beuermann

By using of a model for the propagation of the emitted X-rays through the infalling material and the reemission of the energy deposited by photoabsorption in the optical (and UV) spectral range (Kim & Beuermann, 1995) we calculated Hϒ line spectrum of intermediate polars. Photoabsorption of X-rays by the infalling material is the dominant process in forming the observed energy-dependent rotational modulation of the X-ray flux. X-ray and optical modulations are sensitive to model parameters in different ways. In principle these dependences allow us to obtain improved insight into the geometry of intermediate polars. Some results of our calculation will be presented in this paper in comparison with the Hβ spectrum calculated by Kim & Beuermann (1996).


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