HAMAMATSU R928, R955 Datasheet
Extended Red, High Sensitivity, Multialkali Photocathode
28mm (1-1/8 Inch) Diameter, 9-Stage, Side-On
FEATURES
Wide Spectral Response
R928 ........................................................
R955 ........................................................
High Cathode Sensitivity
Luminous ......................................................
Radiant at 400nm .............................................
High Anode Sensitivity (at 1000V)
Luminous ........................................................
Radiant at 400nm .....................................
Low Drift and Hysteresis
The R928 and R955 feature extremely high quantum efficiency,
high current amplification, good S/N ratio and wide spectral response from UV to near infrared. The R928 employs a UV glass
envelope and the R955 has a fused silica envelope for UV sensitivity extension.
The R928 and R955 are well suited for use in broad-band spectrophotometers, atomic absorption spectrophotometers, emission spectrophotometers and other precision photometric instruments.
185 to 900 nm
160 to 900 nm
250 A/lm
74mA/W
2500A/lm
7.4 10
5
A/W
PHOTOMULTlPLlER TUBES
R928, R955
GENERAL
Parameter Description/Value Unit
Spectral Response
R928
R955
Wavelength of Maximum Response
Photocathode
MateriaI
Minimum Effective Area
Window Material
R928
R955
Dynode
Secondary Emitting Surface
Structure
Number of Stages
Direct Interelectrode Capacitances
Anode to Last Dynode
Anode to All Other Electrodes
Base
Weight
SuitabIe Socket
SuitabIe Socket Assembly
185 to 900 nm
160 to 900 nm
400
Multialkali
8 24
UV glass
Fused silica
Multialkali
Circular-cage
9
Approx. 4 pF
Approx. 6 pF
11-pin base
JEDEC No. B11-88
Approx. 45
E678–11A (option)
E717–21 (option)
nm
mm
g
Figure 1: Typical Spectral Response
TPMSB0001EB
100
R955
10
1
QUANTUM EFFICIENCY (%)
0.1
CATHODE RADIANT SENSITIVITY (mA/W)
0.01
100 200 300
R928
QUANTUM EFFICIENCY
400 500 600 700
WAVELENGTH (nm)
CATHODE
RADIANT
SENSITIVITY
900
800
1000
Subject to local technical requirements and regulat ions, availability of products included in this promotional material may va r y. Please consult with our sales office.
lnformation furnished by HAMA M ATSU is believed to be reliabIe. However, no respon sibility is assumed for possibIe inaccuracies or ommissions. Specifications are
subject to change without notice. No patent right are granted to any of the circuits described herein.
1997 Hamamatsu Photonics K.K.
©
PHOTOMULTlPLlER TUBES R928, R955
MAXIMUM RATINGS (Absolute Maximum Values)
Parameter Value
Supply Voltage
Between Anode and Cathode
Between Anode and Last Dynode
Average Anode Current
Ambient Temperature
–80 to +50
CHARACTERISTlCS (at 25 )
Parameter
Cathode Sensitivity
Quantum Efficiency at Peak Wavelength
Luminous
Radiant at 194nm 18
Red/White Ratio
Blue
Anode Sensitivity
Luminous
Radiant at 194nm 1.8 10
Gain
Anode Dark Current
After 30 minute Storage in the darkness 3 50
B
254nm 52
400nm 74
633nm 41
852nm 3.5
C
D
E
254nm
400nm
633nm
852nm
E
F
1250
250
0.1
Min. Max.
Unit
Vdc
Vdc
mA
R928
Typ.
25.4
(at 260nm)
140 250
0.2
0.3
8
2500400
5.2 10
7.4 10
4.1 10
3.5 10
1.0 10
5
5
5
5
4
7
R955
Min. Max.
Typ.
29.0
Unit
%
(at 220nm)
140 250 A/lm
43 mA/W
56 mA/W
74 mA/W
41 mA/W
3.5 mA/W
0.2
0.3
8 A/lm-b
2500 A/lm400
4.3 10
5.6 10
7.4 10
4.1 10
3.5 10
1.0 10
5
5
5
5
4
7
A/W
A/W
A/W
A/W
A/W
350 nA
ENI(Equivalent Noise Input)
Time Response
E
Anode Pulse Rise Time
Electron Transit Time
Transit Time Spread (TTS)
Anode Current Stability
H
I
J
K
L
Current Hysteresis
Voltage Hysteresis
NOTES
Averaged over any interval of 30 seconds maximum.
A:
The light source is a tungsten filament lamp operated at a distribution tem-
B:
perature of 2856K. Supply voltage is 100 volts between the cathode and
all other electrodes connected together as anode.
Red/White ratio is the quotient of the cathode current measured using a
C:
red filter(Toshiba R-68) interposed between the light source and the tube
by the cathode current measured with the filter removed under the same
conditions as Note B.
The value is cathode output current when a blue filter(Corning CS-5-58
D:
polished to 1/2 stock thickness) is interposed between the light source and
the tube under the same condition as Note B.
Measured with the same light source as Note B and with the voltage distri-
E:
bution ratio shown in Table 1 below.
Table 1:Voltage Distribution Ratio
Electrode K Dy1 Dy2 Dy3 Dy4 Dy5 Dy6 Dy7 Dy8 Dy9 P
Distribution
Ratio
SuppIy Voltage : 1000Vdc
K : Cathode, Dy : Dynode, P : Anode
1111111111
1.3 10
2.2
22
1.2
0.1
1.0
-16
F:
Measured with the same supply voltage and voltage distribution ratio as
Note E after removal of light.
G:
Measured at a supply voltage adjusted to provide an anode sensitivity of
100 A/lm.
ENI is an indication of the photon-limited signal-to-noise ratio. It refers to
H:
the amount of light in watts to produce a signal-to-noise ratio of unity in the
output of a photomultiplier tube.
ENI =
where q = Electronic charge (1.60 10
ldb = Anode dark current(after 30 minute storage) in amperes.
G = Gain.
f = Bandwidth of the system in hertz. 1 hertz is used.
S = Anode radiant sensitivity in amperes per watt at the wave length of peak response.
I:
The rise time is the time for the output pulse to rise from 10% to 90% of the
peak amplitude when the entire photocathode is illuminated by a delta
function light pulse.
2q.ldb.G
S
1.3 10
2.2
22
1.2
0.1
1.0
.
f
-16
-19
coulomb).
W
ns
ns
ns
%
%
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