The pulsed electron accelerator selected for use in the development of ultraviolet laser capability suitable for use in photoexcitation and photoionization studies of the upper atmosphere is reported. Performance figures, installation specifications, and total cost of the equipment are briefly shown, and plans for further studies are outlined

Walters, G. K.

English

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FINAL REPORT
NASA Grant NGR 44-006-169
For Development of Ultraviolet Lasers
Submitted by Professor G. K. Walters, Physics Department, Rice University
This grant of $25,000 made possible the development of an
ultraviolet laser laboratory at Rice University. The proposal
called for purchase, installation, radiation shielding and test
of an intense pulsed electron accelerator as a first step toward
development of an ultraviolet laser capability suitable for use
in photoexcitation and photionization studies of upper atmospheric
species. All proposed tasks were fully accomplished in the grant
period.
The accelerator selected - - a Physics International Modified
Pulsrad 102 - - delivers a current of approximately 1.5 x 104
amperes at about 106 electron volts for about 10- 8 seconds. It is
installed with necessary concrete and lead shielding in the base-
ment of Rice's Space Science and Technology Building. Photographs
of the facility are attached to the original copy of this report.
Our tests have shown that the accelerator performs according to
specifications, perhaps slightly better.
The $18,200 base cost of the accelerator, plus the costs of
shipping, installation, shielding and tests account in full for
the $25,000 grant.
Our. intention is to continue toward the ultimate goal of a
useful ultraviolet laser facility. However, while both argon and
(NAS-C -138632) DEVELOPMENT OF N74-27 0
ULRAVIOLc1 LASERS Final ieport (Rice
Univ.) 3 p HC $4.T CSCL 2E i
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https://ntrs.nasa.gov/search.jsp?R=19740018891 2020-03-23T08:44:53+00:00Z
21-3
xenon lasers have been realized in several US laboratories l-, work
done in this and other laboratories during the past year has demon-
strated that these rare-gas molecular dissociation UV lasers operate
at unexpectedly and disappointingly low efficiency compared to
theoretical expectations. 4 There is'concensus agreement that much
more work must be done on studying lifetimes and de-excitation
processes involved in the sequences of reactions leading to popu-
lation of the levels important for laser action. Therefore the Rice
laboratory is currently concentrating its efforts on such fundamental
dynamics studies with the belief that in the long run this is the
most direct route to realization of useable molecular disociation
UV lasers. This program of fundamental research is funded as part
of an on-going AEC research contract; hence it does not seem appro-
priate to request additional NASA support at this time.
It is our intention, however, to re-activate molecular
dissociation UV laser development at Rice after the fundamental
program reaches full productivity and is providing the kinds of
information needed to guide the laser effort. We expect this to
occur within the next few months. At that time we would like to
request NASA support for the continuation of the program begun
under the original grant.
REFERENCES
1H. A. Koehler, L. J. Ferderber, D. L. Redhead and P. J. Ebert,
Appl. Phys. Letters 21, 198 (1972).
J. B. Gerardo and A. W. Johnson, IEEE Journal of Quantum
Electronics QE-9, 748 (1973).
C. K. Rhodes, IEEE Journal of Quantum Electronics QE-10, 153 (1974).
4Laser Fusion Research Progress Report, January-June 1973, Sandia
Laboratories. p. 22.
April 15, 1974
G. K..Walters
Principal Investigator
UV Laser Facility - Rice University
-7f
Pulsrad 102 Accelerator Installed on Tracks
- i i--
in Space Science and Technology Building
E 0L
E o .'i
a)
Pulsrad 102 Control Desk
showing Concrete Block Shielding
- -3--


Development of ultraviolet lasers

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