October 2000 Newsletter - Naval Postgraduate School

Professor Alan Ross, the Navy TENCAP Chair Professor, has
studied soft errors in microprocessors and space systems.
Associate Professors John Ciezki and Robert Ashton, Department
of Electrical and Computer Engineering, have examined
radiation effects in power devices and circuits, and Assistant
Professor Todd Weatherford has examined solid state
transistor modeling and material manufacturing issues.
The radiation facilities at NPS are unique. The LINAC
provides an electron beam pulse train of 100 MeV electrons
(up to 1000 rads per microsecond pulse) useful for studying
displacement damage in microelectronics or solar cells for
applications in the Van Allen belts and even Jupiter’s radiation
belts. This is the only LINAC in operation that produces
electrons in the 100 MeV energy range. The facility
can also be used to study both Total Dose and some weapons
effects. The Flash X-ray facility produces a gamma pulse of
100 rads in approximately 10-20 nanoseconds to simulate a
weapons effect.
Both facilities are available to NPS faculty and outside
users for periods of one month at a time, with up to 80
hours of “beam time” in a month. Charges are $2500/month
for faculty and $9000/month for outside users.
As mentioned earlier, the availability of thesis students
with clearance provides an advantage with many of the
projects that are classified or limited to U.S. citizens. Addi-
RESEARCH CENTER
RAD-HARD SEMICONDUCTOR CHIPS, continued from page 16
THE “LINAC,”continued from page 16
The realization of the NPS LINAC is shown in
Figure 1, where each of three high power klystrons
deliver power to one ten foot accelerator section. The
klystrons require a high voltage high current source,
called a modulator in the diagram. The electron beam
is deflected by magnets to the experiment area. The
energy of the electron beam is expressed in electron
volts, one eV is the energy of an electron accelerated by
one volt. Each 10-foot section gives energy of 30
million electron volts, i.e. 30 MeV per section. An
advantage of the LINAC concept is that higher energy
is obtained by having more accelerator sections. The
NPS LINAC yields about 100 MeV from 3 sections,
the Stanford Mark 3 accelerator yielded 1000 MeV
from 30sections, while the 960 section, 2 mile long
Stanford Linear Accelerator Center (SLAC) accelerator
yielded 20,000 MeV before the several upgrades.
--continued on page 49
tionally the NPS students are familiar with the satellite or
weapon programs in which the research supports. Most
student research has been involved in collaborations with
industry such as; Motorola, Honeywell, Lockheed-Martin,
Hughes, TRW, Vitesse Semiconductor, universities; UC
--continued on page 49
The Flash X-ray facility shown opened for maintenance.
X-rays are produced in an adjacent room after 1,200,000
volts are discharged from the capacitor banks shown inside
the oil chamber.
Figure 1. Design of NPS Linear Accelerator.
NPS Research page 17
October 2000