Abstract
Measurements were made on a low-energy positron beam apparatus in an attempt to increase the efficiency of the slow positron yield from radioisotopes. A study was made to sweep thermalized positrons to the surface of a silicon wafer with an applied electric field at 298 and 140 K. Temperature studies were also made on more conventional Pt and Pt+MgO powder moderators and the results are discussed. The role of the MgO powder has been clarified, though fundamental questions remain. The positron apparatus beam and relevant information regarding sources, temperature and magnetic fields are discussed in sufficient detail so that such a slow positron beam utilizing a “conventional” slow positron moderator could be easily duplicated for use in solid state studies.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
W.H.Cherry: Ph.D. Thesis, Princeton University (1958) unpublished
J.M.J.Madey: Phys. Rev. Lett.22, 784 (1169)
D.G.Costello, D.E.Groce, D.F.Herring, J.Wm.McGowan: Phys. Rev. B5, 1433 (1972)
B.Jaduszliwer, W.C.Keever, D.A.L.Paul: Can. J. Phys.50, 1414 (1972)
W.C.Keever, B.Jaduszliwer, D.A.L.Paul: InAtomic Physics 3 (Plenum Press, New York 1973) p. 561
K.F.Canter, P.G.Coleman, T.C.Griffith, G.R.Heyland: J. Phys. B5, L 167 (1972)
References to positron-gas scattering work before 1975 can be found in P.G. Coleman, T.C. Griffith, G.R. Heyland, T.L. Killeen: InAtomic Physics 4 (Plenum Press, New York 1975) p. 355
W.E.Kauppila, T.S.Stein, G.Jesion: Phys. Rev. Lett.36, 580 (1976)
K.F.Canter, A.P.Mills,Jr., S.Berko: Phys. Rev. Lett.34, 177 (1975)
A.P.Mills, Jr., S.Berko, K.F.Canter: Phys. Rev. Lett.34, 1541 (1975)
D.W.Gidley, P.W.Zitzewitz, K.A.Marko, A.Rich: Phys. Rev. Lett.37, 729 (1976)
I.K.MacKenzie: Phys. Lett.30 A, 115 (1969)
R.H.Evans:The Atomic Nucleus (McGraw-Hill, New York 1955) p. 628
B.Bergersen, E.Pajanne, P.Kubica, M.J.Scott, C.H.Hodges: Solid state Commun.15, 1377 (1974)
W.Brandt: Radiation Effects on Solid Surfaces,Advances in Chemistry Series 158, ed by M.Kaminski (American Chemical Society, New York 1976) p. 219
C.H.Hodges: M.J.Stott: Phys. Rev. B7, 73 (1973)
R.M.Nieminen, C.H.Hodges: Solid State Commun.18, 1115 (1976)
S.M.Curry, A.L.Schawlow: Phys. Lett.37 A, 5 (1971)
K.F.Canter, A.P.Mills, Jr., S.Berko: Phys. Rev. Lett.33, 7 (1974)
J.D.Jackson:Classical Electrodynamics (Wiley, New York 1962)
W.E.Kauppila, T.S.Stein, G.Jesion, M.S.Dababneh, V.Pol: Rev. Sci. Instrum.48, 822 (1977)
A.P.Mills,Jr., L.Pfeiffer:Phys. Lett.63 A, 118 (1977)
H.Weisberg, S.Berko: Phys. Rev.154, 249 (1967)
J.P.Pendrys, B.T.A.McKee, A.T.Stewart: Appl. Phys.4, 333 (1974)
C.A.Bailey: InAdvanced Cryogenics, ed. by C.A.Bailey (Plenum Press, New York 1971) p. 317
K.G.Lynn: To be published. The positronium fraction has been measured in an ultra-high vacuum chamber as a function of sample temperature and the incident positron energy. The effect of trapping by vacancies has been found.
Author information
Authors and Affiliations
Additional information
This submitted manuscript has been authored under contract EY-76-C-02-0016 with the U.S. Department of Energy. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes.