An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Regulla DF, Deffner U.Regulla DF, et al.Int J Rad Appl Instrum A. 1989;40(10-12):1039-43. doi: 10.1016/0883-2889(89)90038-5.Int J Rad Appl Instrum A. 1989.PMID: 2559052