摘要:

Comparisons previously drawn between the image of a field ion plane and a Fresnel zone plate are reexamined. It is shown that such images are more generally described as aberrated binary zone plates, and that the relationship between their focal lengths and the imaging parameters is more complex than previously believed.

ISSN:0003-6951    

DOI:10.1063/1.1654844

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

An attempt was made to detect cosmic ray tracks using a pulsed TEA CO2laser. Within 4 &mgr;sec of the passage of a cosmic ray through a pressurized cell, a laser beam of 4 J/cm2energy density at 10.6 &mgr; was fired. Pure argon and argon‐krypton mixtures were studied at pressures up to 12 atm. Spots of light were seen but no tracks. Laser damage to the cell windows was the limiting factor. An alternative detector using an initial high‐voltage pulse followed by a laser pulse is proposed.

ISSN:0003-6951    

DOI:10.1063/1.1654845

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A fast‐neutron dosimeter is described, the operation of which is based on the detection ofFcenters produced in MgO by displacement collisions. TheF‐center production rate is greatly enhanced by hydrogenous surroundings from which recoil protons are ejected. The absorbed dose is measured by means of the 350 °C exoelectron emission peak. The response is linear from 10 to 600 rad (tissue) and approximately independent of neutron energy from 2 to 15 MeV. The response to fast neutrons divided by the response to &ggr; rays is [inverted lazy s] 0.90 on a tissue‐rad basis.

ISSN:0003-6951    

DOI:10.1063/1.1654846

出版商:AIP    

年代:1973

数据来源: AIP