A metastable state of around 10⁻⁶ seconds in Re¹⁸⁷

MISSING IMAGE

Material Information

Title:
A metastable state of around 10⁻⁶ seconds in Re¹⁸⁷
Series Title:
United States. Atomic Energy Commission. MDDC ;
Alternate Title:
A metastable state of around 10⁻⁶ seconds in Re-187
Physical Description:
2 p. : ill. ; 27 cm.
Language:
English
Creator:
De Benedetti, S
McGowan, F.K
Clinton Laboratories
U.S. Atomic Energy Commission
Publisher:
Technical Information Division, Oak Ridge Directed Operations
Place of Publication:
Oak Ridge, Tenn
Publication Date:

Subjects

Subjects / Keywords:
Rhenium   ( lcsh )
Energy levels (Quantum mechanics)   ( lcsh )
Genre:
federal government publication   ( marcgt )
bibliography   ( marcgt )
technical report   ( marcgt )
non-fiction   ( marcgt )

Notes

Bibliography:
Bibliography: p. 1.
Restriction:
"Date Declassified: January 23, 1947"
Statement of Responsibility:
by S. De Benedetti and F.K. McGowan.
General Note:
Manhattan District Declassified Code
General Note:
"Date of Manuscript: Unknown"

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 005024110
oclc - 277773848
System ID:
AA00009269:00001


This item is only available as the following downloads:


Full Text
c7r 'M

P 1ss 1 9
^-t!15


MDDC 1115


UNITED STATES ATOMIC ENERGY COMMISSION








A METASTABLE STATE OF AROUND 106 SECONDS IN Rei"



by


S. De Benedetti
F. K. McGowan




Clinton Laboratories








This document consists of 2 page
Date of Manuscript: Unknown
Date Declassified: January 23, 1947


This document is issued for official use.
Its issuance does not constitute authority
to declassify copies or versions of the
same or similar content and title
and by the same author (s).




Technical Information Division, Oak Ridge Directed Operations
Oak Ridge, Tennessee


CLir"'J
APy





















S. ,: :....
::' .* H i : 4 '^:



.. .: : ,. F ', '. i
~-i










.
I



































* : : *.; .
:ii:ii

























:1.




... .'


.H (




-a k '- .
....







,,.: .
." : ;
:* ,. ... .*::^ ..'
.;. ... *
...* x. :* ." .. *"
',;.. ..* ; :..


;. ,...,

















A METASTABLE STATE OF AROUND 10-' SECONDS IN Re'"


By S. De Benedetti and F. K. McGowan


Using sources of W"' (24 hrs) and an experimental arrangement similar to that described in a
previous letter'we were able to detect delayed coincidences whose number as a function of time is
shown in Figure 1. It appears from this curve that the disintegration of W"7 leads to a metastable state
Re1'7 which in turn decays to the ground state with a half-life of about one microsecond (only statisti-
cal errors indicated on the figure; errors involved in the calibration of the time scale may be consider-
ably larger).
In order to increase the counting rate by eliminating absorption in the counter windows, the two
GM counters and the source (deposited on a thin aluminum foil) were located within the same envelope
(Figure 1). Since the minimum delay used was 1.5 psec, it was necessary to prove that the recorded
coincidences were not due to simultaneous rays (immediate internal conversion, or radiation scattered
from one to the other counter) which gave delayed pulses because of the time lag of the counters. To
test this point,$ rays from RaE were sent through both counters and it was lound that these did not
give any delayed coincidences despite the large number of immediate coincidences recorded.
Absorption measurements were performed under the geometrical conditions described in the
previous letter' using 2 mica window GM counters. The absorption curve of the disintegration elec-
trons followed by a delayed ray proved that the metastable state follows the softer part of the fi spec-
trum2 of W"s7. Some 7 radiation also seems to precede the metastable state. From absorption measure-
ments on the delayed electrons, it appears the energy of the delayed 7 rays may correspond to any one
of the three soft lines 1.086, .101, or .130 Mev) previously observed in the spectrum of We'. However,
it seems probable that the metastable state is associated to the .130 Mev transition since this has been
observed with a f spectrometer to be strongly converted.3
The disintegration of the metastable state is accompanied by a soft electromagnetic radiation
(less than 100 Kv) which could be either the unconverted 7 ray from the metastable state (which in this
case should be attributed to the 86 Kv transition), or a V ray following it, or the atomic X-radiation from
Re. The number of delayed electrons per disintegration of W'" was evaluated to 0.1. Since not all f
rays of W'7 lead to the metastable state, the internal conversion coefficient must be larger than this
value.

This work was done under the auspices of the Manhattan District.




REFERENCES
1. De Benedetti, S., and F. K. McGowan, Phys. Rev. 70: 569 (1946).

2. Sullivan, W. H., Phys. Rev. 68: 277 (1945).
3. We are indebted to L. C. Miller and L. F. Curtiss for the communication of this result.


MDDC 1115










2 ] MDDC -1115

















T = .65 p-SEC




Lu
a-
j 0.001


A


z .SOURCE



o 0.0001 u
a o


3
DELAY IN g-SEC


Figure 1.










:!
:::'


































.:;. '*



























































































":.,
.: *: ,
















































rJ; *?.:




UNIVERSITY OF FLORIDA


3 1262 08909 7496

". .
















i


a lb"d
I"!:




Full Text
xml version 1.0 encoding UTF-8
REPORT xmlns http:www.fcla.edudlsmddaitss xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.fcla.edudlsmddaitssdaitssReport.xsd
INGEST IEID ENQC1JNE9_ZFPV1F INGEST_TIME 2012-03-02T22:51:48Z PACKAGE AA00009269_00001
AGREEMENT_INFO ACCOUNT UF PROJECT UFDC
FILES