Photosensor
is meant for:
- Automatic
launching of streak cameras from the beginning
stage (the low-illuminating one as
usual) of registered process
(launching channel);
- Lockout
pulse supply at a camera for rapid (≤ 0, 2 μs) decrease of streak
transferor’s
microcannel plate gain under registered process brightness rise to a
value
exceeding the critical one and being able to total or partial loss of
registered information under over-illumimation (saturation) of image
sweep.
Possible
application of the photosensor:
synchronization of various detectors –streak cameras, oscilographes,etc with light emitting processes in
such
fields of science and technologies as:
- Physics of shock waves,
- Laser physics,
- Nuclear physics,
- Plasma physics,
- electrical raptures and discharges including
lightnings , artificial
as well as nature (lightnings).
Main components
of FD-001 photosensor:
- two optical systems with replaceable lenses
supplied with an aperture and limiting masks;
- set of color and interference
filters;
- periscope;
- two photoamplifiers;
- two comparators of photocurrent;
- two lockout pulses formation systems.
Operational principle
Launching channel is usually used for
camera synchronization at the beginning
(low- illuminating) stage of a charge, the control channel is meant for
camera’s sensitivity decrease at the moment of the final (extremely
bright)
stage of a charge with the photosensor use with streak cameras special
intended
for charge image registration in
long
air intervals
and
for lightnings image
detections.
Light signal of a registered
process is transferred into the electrical one with using a photomultiplier and
supplied to the
comparator. After electrical signal amplitude is achievement the
control level
established by the comparator a limited scheme is acted. The scheme
signal
amplified and transferred into a rectangular pulse is transmitted from
launching channel’s input to the streak camera’s launch. A signal
obtained from
control unit’s output is used for control of streak tube’s microchannel
plate
gain.
Two types of input single-lens input objectives are possible. The first
objective of 50 mm focus length procures 100
angle of vision.
Another one of 28 mm focus length is meant for
380 angle
of vision
achievement
. Selection of one of the input
objectives is made
according to a type of the objective located at streak camera’s input,
for
example «UVO-01» - ultraviolet (F=50mm), «Industar-61» (F=50mm) or
«Mir-10»
(F=28mm).
In
order to filter a signal and background color filters SZS-21, ZhS-18
and
interference filter at 386nm wavelength are provided. To stepped
decrease of a
signal and background neutral filters of D=0.6; D=1.4 and D=3 density
are set
at the input objectives.
Photosensor characteristics
|
Range
of photoamplifier spectral sensitivity, nm
|
≤ 300
– ≥
800
|
|
Sensitivity
of the photocathode at the maximum of spectral characteristic, mA / W
|
≥ 40
|
|
Diameter
of photocathode useful area, mm
|
10
|
Focus length and replaceable objective's aperture
First
objective
second
objective
|
50 / 1:2
28 / 1:1.5
|
|
Dead
time, µs
|
≤ 0.3
|
Input lockout pulse parameters at 50 Ohm
burden,
Launching channel/control unit
polarity
amplitude, V
duration, µs
rise time, µs
|
+
6-10
10-30
≤
0.2
|
|
Dimensions,
mm ×mm × mm
|
400×260×240
|
|
Weght,
kg
|
≤
3
|
Power
supply, W:
alternating
current of 50-60 Hz frequency
constant current (option)
|
85
– 264
18
– 36
|
|
Power
consumption, W
|
≤ 5
|
