Energy and angular distributions of electrons from ion impact on atomic and molecular hydrogen .4. 28-114-keV He++H collisions

被引:16
作者
Hsu, YY [1 ]
Gealy, MW [1 ]
Kerby, GW [1 ]
Rudd, ME [1 ]
机构
[1] OAK RIDGE NATL LAB, DIV PHYS, OAK RIDGE, TN 37831 USA
关键词
D O I
10.1103/PhysRevA.53.303
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
Absolute ionization cross sections for 28-114-keV helium ion impact on atomic hydrogen, differential in energy and angle of the ejected electrons, have been obtained from crossed-beam measurements and previously measured cross sections for molecular hydrogen targets. A radio frequency discharge source produced a mixed atomic and molecular target with a typical dissociation fraction of 74%. Energy spectra were measured from 1.5 to 130 eV by an electrostatic analyzer with a resolution of 5%. The angular range was 15 degrees-160 degrees. Results are compared with calculations based on the first Born, continuum-distorted-wave-eikonal-initial-state, and classical trajectory Monte Carlo methods. Total electron yields are obtained by combining calculations that are separately performed for liberating the target and projectile electrons. Model potentials are used to represent the interparticle-separation-dependent screening of the nuclear charges experienced by the electrons. Though projectile electron emission is a negligible component of the total ionization cross section for the present collision energies, its contribution is significant for particular regions of the spectrum of ejected electrons. Through comparison with our proton-impact data [Kerby et al., Phys. Rev. A 51, 2256 (1995)], differences and similarities are demonstrated owing to the common asymptotic charge of these two projectiles but differing nuclear charges and the electron carried by the He+ ion. Comparisons are also made illustrating the differences between atomic and molecular hydrogen targets.
引用
收藏
页码:303 / 311
页数:9
相关论文
共 19 条
[1]  
Barnett C. F., 1990, Report ORNL-6086/V1
[2]   INELASTIC COLLISIONS BETWEEN HEAVY PARTICLES .1. EXCITATION AND IONIZATION OF HYDROGEN ATOMS IN FAST ENCOUNTERS WITH PROTONS AND WITH OTHER HYDROGEN ATOMS [J].
BATES, DR ;
GRIFFING, G .
PROCEEDINGS OF THE PHYSICAL SOCIETY OF LONDON SECTION A, 1953, 66 (407) :961-971
[4]   INELASTIC COLLISIONS BETWEEN HEAVY PARTICLES .6. ELECTRON LOSS FOR FAST HE+ IONS PASSING THROUGH ATOMIC HYDROGEN, AND IONIZATION OF HYDROGEN ATOMS BY FAST HE+ IONS [J].
BOYD, TJM ;
MOISEIWITSCH, BL ;
STEWART, AL .
PROCEEDINGS OF THE PHYSICAL SOCIETY OF LONDON SECTION A, 1957, 70 (02) :110-116
[5]   RIGOROUS SOLUTION OF 3-BODY SCATTERING PROCESSES IN DISTORTED-WAVE FORMALISM [J].
DODD, LR ;
GREIDER, KR .
PHYSICAL REVIEW, 1966, 146 (03) :675-&
[6]  
FADEEV LD, 1961, ZH EKSP TEOR FIZ, V12, P1014
[7]   INDEPENDENT-PARTICLE-MODEL POTENTIALS FOR ATOMS AND IONS WITH 36 LESS THAN, Z LESS-THAN-OR-EQUAL-TO 54 AND A MODIFIED THOMAS-FERMI ATOMIC ENERGY FORMULA [J].
GARVEY, RH ;
JACKMAN, CH ;
GREEN, AES .
PHYSICAL REVIEW A, 1975, 12 (04) :1144-1152
[8]   ENERGY AND ANGULAR-DISTRIBUTIONS OF ELECTRONS FROM ION IMPACT ON ATOMIC AND MOLECULAR-HYDROGEN .1. 20-114-KEV H++H-2 [J].
GEALY, MW ;
KERBY, GW ;
HSU, YY ;
RUDD, ME .
PHYSICAL REVIEW A, 1995, 51 (03) :2247-2255
[9]   Energy and angular distributions of electrons from ion impact on atomic and molecular hydrogen .3. 28-114-keV He++H-2 [J].
Hsu, YY ;
Gealy, MW ;
Kerby, GW ;
Rudd, ME .
PHYSICAL REVIEW A, 1996, 53 (01) :297-302
[10]  
KERBY GW, 1995, PHYS REV A, V51, P2256, DOI 10.1103/PhysRevA.51.2256