MAXIMUM RATINGS (Absolute Maximum Values)

Parameter

Value

Supply Voltage

Between Anode and Cathode

Between Anode and Last Dynode

1250

250

0.1

Vdc

Vdc

mA

Unit

CHARACTERISTlCS (at 25

°C)

NOTES

Parameter

Min.

Typ.

Typ.

Max.

R7447

for General Purpose

R7447P

for Photon Counting

Cathode Sensitivity

Anode Sensitivity

After 30minutes Storage in the darkness

0.2

2.0

A:

B:

C:

D:

E:

F:

G:

H:

J:

Averaged over any interval of 30 seconds maximum.

The light source is a tungsten filament lamp operated at a distribution tem-

perature of 2856K. Supply voltage is 150 volts between the cathode and all

other electrodes connected together as anode.

The value is cathode output current when a blue filter(Corning CS-5-58

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 anode-to-

cathode supply voltage and voltage distribution ratio shown in Table 1 be-

low.

Measured with the same supply voltage and voltage distribution ratio as

Note D after removal of light.

Measured at the voltage producing the gain of 1

ENI is an indication of the photon-limited signal-to-noise ratio. It refers to

the amount of light in watts to produce a signal-to-noise ratio of unity in the

output of a photomultiplier tube.

where

q = Electronic charge (1.60

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.

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.

The electron transit time is the interval between the arrival of delta function

light pulse at the entrance window of the tube and the time when the anode

output reaches the peak amplitude. In measurement, the whole photo-

cathode is illuminated.

K:

L:

Also called transit time jitter. This is the fluctuation in electron transit time

between individual pulses in the signal photoelectron mode, and may be

defined as the FWHM of the frequency distribution of electron transit times.

Hysteresis is temporary instability in anode current after light and voltage

are applied.

ENI =

S

2q.ldb.G. f

Current Hysteresis

Voltage Hysteresis

0.1

1.0

Radiant at 410nm (Peak)

70

8

2.2

22

1.2

Electrodes

K

Dy1 Dy2 Dy3 Dy4 Dy5 Dy6 Dy7 Dy8 Dy9

P

Distribution

Ratio

1

111

1

1

1111

SuppIy Voltage : 1000Vdc

K : Cathode,

Dy : Dynode,

P : Anode

Quantum Efficiency at 300nm

80

100

24

Unit

PHOTOMULTlPLlER TUBES R7447, R7447P (For Photon Counting)

Radiant at 400nm

8.4

1200

1000

3.30

Min.

Max.

0.2

0.5

nA

0.1

1.0

%

%

70

mA/W

8

µA/lm-b

2.2

22

1.2

ns

ns

ns

80

100

µA/lm

24

%

8.4

A/W

1200

A/lm

1000

1.2

1.2

10

50

cps

3.30

W

Table 1:Voltage Distribution Ratio

Hysteresis =

× 100(%)

lmax.

li

lmin.

(1)Current Hysteresis

The tube is operated at 750 volts with an anode current of 1 micro-ampere for

5 minutes. The light is then removed from the tube for a minute. The tube is

then re-illuminated by the previous light level for a minute to measure the

variation.

(2)Voltage Hysteresis

The tube is operated at 300 volts with an anode current of 0.1 micro-ampere

for 5 minutes. The light is then removed from the tube and the supply voltage

is quickly increased to 800 volts. After a minute, the supply voltage is then

reduced to the previous value and the tube is re-illuminated for a minute to

measure the variation.

TPMSB0002EA

TIME

max.

l

min.

l

i

l

0

5

6

7 (minutes)