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1.
Nature ; 465(7297): 454-7, 2010 May 27.
Article in English | MEDLINE | ID: mdl-20505723

ABSTRACT

Atomic nuclei have a shell structure in which nuclei with 'magic numbers' of neutrons and protons are analogous to the noble gases in atomic physics. Only ten nuclei with the standard magic numbers of both neutrons and protons have so far been observed. The nuclear shell model is founded on the precept that neutrons and protons can move as independent particles in orbitals with discrete quantum numbers, subject to a mean field generated by all the other nucleons. Knowledge of the properties of single-particle states outside nuclear shell closures in exotic nuclei is important for a fundamental understanding of nuclear structure and nucleosynthesis (for example the r-process, which is responsible for the production of about half of the heavy elements). However, as a result of their short lifetimes, there is a paucity of knowledge about the nature of single-particle states outside exotic doubly magic nuclei. Here we measure the single-particle character of the levels in (133)Sn that lie outside the double shell closure present at the short-lived nucleus (132)Sn. We use an inverse kinematics technique that involves the transfer of a single nucleon to the nucleus. The purity of the measured single-particle states clearly illustrates the magic nature of (132)Sn.

2.
Appl Opt ; 16(4): 887-92, 1977 Apr 01.
Article in English | MEDLINE | ID: mdl-20168607

ABSTRACT

The Naval Research Laboratory XUV solar spectrograph (S082A) and spectroheliograph (S082B) in the Apollo Telescope Mount of Skylabrequired Schumann-type photographic film in quantities greater than had ever before been needed. The procurement, testing, handling, and processing of this film are described. Eastman Kodak type 104 and a small quantity of type 101 were used. All problems that were anticipated were met satisfactorily, and excellent results were obtained. Two new problems arose; fog associated with the stainless steel carriers and a large reduction of contrast and maximum density for the flight film that was exposed to the space vacuum.

3.
Appl Opt ; 16(4): 893-7, 1977 Apr 01.
Article in English | MEDLINE | ID: mdl-20168608

ABSTRACT

An instrument for recording extreme ultraviolet television images of the sun was flown in the Apollo Telescope Mount on Skylab. Solar radiation in the 171-630 A wavelength range, defined by the transmission band of three thin-film aluminum filters, was focused onto a p-quaterphenyl photon conversion layer by a platinum-coated mirror at normal incidence. The conversion layer was attached to the faceplate of a low light level SEC vidicon. An onboard video monitor enabled the Skylab crews to observe the images in realtime and to identify and follow the development of solar features. Images were also transmitted to the mission control center, where they were used in planning the ATM observing schedule.

4.
Appl Opt ; 16(4): 922-5, 1977 Apr 01.
Article in English | MEDLINE | ID: mdl-20168613

ABSTRACT

A persistent image-converter device was utilized to make visible to the astronaut solar images that were isolated, instantaneous flashes on the ATM TV monitors. In addition, these instantaneous images, as well as normal TV images, were recorded with a Polaroid SX-70 camera for study by the astronauts.

5.
Science ; 160(3831): 990-1, 1968 May 31.
Article in English | MEDLINE | ID: mdl-17768892

ABSTRACT

A rocket-borne photometer has detected far ultraviolet night glow radiations that are identified as Lyman-beta (HI 1026 angstroms), and the helium lines at 304 or 584 angstroms, or at both. At an altitude of 227 kilometers the measured intensity for Lyman-beta was about 10 rayleighs. The discrimination characteristics of the broad-band helium radiation filter give helium line intensities, at 227 kilometers, of 4.8 and 12 rayleighs, respectively, pending identification of the wavelength of the radiation as 304 or 584 angstroms. These ultraviolet radiations appear sufficient to maintain the night E and F(1) regions of the ionosphere.

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