摘要:

The most important recent developments in materials for polarized targets and in polarizing techniques are reviewed.

ISSN:0094-243X    

DOI:10.1063/1.32808

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A brief review is given of various methods for producing spin‐polarized electrons. Sources based on photoionization of polarized Li atoms, ionization of Rb atoms and photoemission from GaAs with circularly polarized light, field emission from ferromagnetic W/EuS, and chemi‐ionization of polarized He atoms will be discussed. The first three methods have been used in subatomic investigations. The present characteristics and merits of polarized electron sources are compared, and future developments expolored.

ISSN:0094-243X    

DOI:10.1063/1.32809

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The direct production of3He+(2S) states in an ion source allows considerable simplification of the Lamb shift method developed at the university of Birmingham, England. Thbe status of the Laval project along these lines is described. Another scheme based on the 23S1state of3He (neutral) using the atomic beam method is also discussed, as it appears to be far superior in order to attain high intensities of polarized3He beams.

ISSN:0094-243X    

DOI:10.1063/1.32810

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The use of tunable lasers to achieve nuclear polarization is discussed and illustrated with several examples. New techniques for efficient polarization of high density alkali vapors are shown to be useful in production of a charge exchange medium for polarized beams as well as polarized targets for special applications.

ISSN:0094-243X    

DOI:10.1063/1.32811

出版商:AIP    

年代:1981

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.32812

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The need for rapid spin reversal technique in polarization experiments is discussed. The ground‐state atomic‐beam source equipped with two rf transitions for hydrogen can be reversed rapidly and is now in use on several accelerators. It is the optimum choice provided the accelerator can accept H+ions. At present all rapid reversal experiments using H−ions are done with Lamb‐shift sources; however, this is not a unique choice. Three methods for the reversal of the spin of the atomic beam within the Lamb‐shift source are discussed in order of development. Coherent intensity and perhaps focus modulation seem to be the biggest problems in both types of sources. Methods for reducing these modulations in the Lamb‐shift source are discussed. The same Lamb‐shift apparatus is easily modified to provide information on the atomic physics of quenching of the 2S1/2states versus spin orientation and this is also discussed.

ISSN:0094-243X    

DOI:10.1063/1.32813

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A review of the basic principles and new methods for the production of polarized ions is presented. It is shown that schemes for nearly all kind of polarized ions exist. The new developments and recent technical designs are described and the performance of a variety of different type of sources is discussed. This progress made it now possible to accelerate polarized ions by all types of accelerators. For H+and D+ions, polarized beam intensities in excess of 100 &mgr;A are now available for injection; for polarized negative hydrogen ions, beam outputs from the sources of 10 &mgr;A are expected in the near future. The importance of the optical properties and other characteristic features of polarized beams for high precision measurements are discussed.

ISSN:0094-243X    

DOI:10.1063/1.32814

出版商:AIP    

年代:1981

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.32815

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We have measured the polarization of neutrons produced from the reaction pd→n&drarr; at a laboratory angle of 20° at an incident proton kinetic energy of 800 MeV. For the highest energy neutron peak at ∼665 MeV, as well as for the broad pion production peak at ∼325 MeV, the neutron polarization has been found to be ∼0.20. The measured polarization for the quasielastic process has been found to be in good agreement with the free np analyzing power measurements. Such a polarized neutron beam, having a broad spectrum of momenta from 800 to 1300 MeV/c has been used at LAMPF for free np spin correlation measurements.

ISSN:0094-243X    

DOI:10.1063/1.32761

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The spin transfer parameters,KNNandKLLhave been measured in pd→nXand p9Be→nXat 0° and 800 MeV. The rather large values ofKLLdemonstrate that this transfer mechanism will provide a useful source of polarized neutrons at LAMPF energies.

ISSN:0094-243X    

DOI:10.1063/1.32762

出版商:AIP    

年代:1981

数据来源: AIP