Charge integration in external-beam PIXE

被引:31
作者
Lill, JO
机构
[1] Abo Akad Univ, Dept Phys, FIN-20500 Turku, Finland
[2] Abo Akad Univ, Accelerator Lab, FIN-20500 Turku, Finland
关键词
PIXE; charge integration; external beam; low current measurements; second positive band system;
D O I
10.1016/S0168-583X(98)01074-X
中图分类号
TH7 [仪器、仪表];
学科分类号
0804 ; 080401 ; 081102 ;
摘要
Direct measurements of the beam current in external-beam PIXE are difficult due to the ionization of air molecules. A method for indirect charge integration has been earlier presented by our research group. The method utilizes the light emission from air molecules excited by the particle beam. The light emission originates from the second positive band system in N-2. The light was measured with a photomultiplier tube. The geometry and the electronics have been improved during the six years that have passed since the method was taken into use. The current from the PM-tube is today about 210 times higher than the particle beam current measured by the means of a Faraday cup. This amplification is useful in the monitoring of small beam currents. The linearity and accuracy of the improved system are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:114 / 117
页数:4
相关论文
共 7 条
[1]   PIXE-ANALYSIS WITH 6-MEV H-2(+)-IONS [J].
DAHLBACKA, J ;
LINDBLOM, P .
PHYSICA SCRIPTA, 1979, 20 (5-6) :655-656
[2]   Electron-impact excitation of the second positive band system (C-3 Pi(u)->B-3 Pi(g)) and the C-3 Pi(u) electronic state of the nitrogen molecule [J].
Fons, JT ;
Schappe, RS ;
Lin, CC .
PHYSICAL REVIEW A, 1996, 53 (04) :2239-2247
[3]  
JOHANSSON SAE, 1995, SERIES MONOGRAPHS AN, V133
[4]   A NOVEL METHOD FOR CHARGE INTEGRATION IN EXTERNAL-BEAM TTPIXE - APPLICATION TO ANALYSES OF BIOLOGICAL-MATERIALS [J].
LILL, JO ;
SAARELA, KE ;
HERNBERG, FJ ;
HESELIUS, SJ ;
HARJU, L .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 1993, 83 (03) :387-393
[5]  
Pearse R. W. B., 1976, IDENTIFICATION MOL S
[6]  
1995, MICROCAL ORIGIN 4 0
[7]  
1977, CURRENT INTEGRATOR 5