MAXIMUM RATINGS (Absolute Maximum Values)

CHARACTERISTlCS (at 25

°C)

PHOTOMULTIPLIER TUBES R2949

NOTES

A:

B:

C:

D:

E:

Averaged over any interval of 30 seconds maximum.

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

temperature of 2856K. Supply voltage is 100 V between the cathode and

all other electrodes connected together as anode.

Red/White ratio is the quotient of the cathode current measured using a

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

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.

H:

J:

K:

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.

Hysteresis is temporary instability in anode current after light and voltage

are applied.

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.

F:

G:

Measured with the same supply voltage and voltage distribution ratio as

Note E after 30 minute storage in darkness.

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.

ENI =

S

2q.ldb.G.

∆f

Electrode

K

Dy1 Dy2 Dy3 Dy4 Dy5 Dy6 Dy7 Dy8 Dy9

P

Distribution

Ratio

11

1

1

1

1

1

1

1

1

SuppIy Voltage: 1000 V, K: Cathode,

Dy: Dynode,

P: Anode

Table 1:Voltage Distribution Ratio

Hysteresis =

× 100 (%)

lmax.

li

lmin.

TPMSB0002EA

TIME

max.

l

min.

l

i

l

0

5

6

7 (minutes)

Value

1250

250

0.1

V

V

mA

Unit

Parameter

Supply Voltage

Typ.

Unit

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

500

—

25

—

—

—

—

—

%

µA/lm

mA/W

mA/W

mA/W

mA/W

mA/W

—

—

A/lm

A/W

A/W

A/W

A/W

A/W

—

nA

W

ns

ns

%

%

25.3

200

18

52

68

41

3.5

0.3

7.5

2000

1.8

5.2

6.8

4.1

3.5

1.0

300

3

2

1.2

2.2

22

0.1

1.0

Max.

Min.

Quantum Efficiency

Radiant

Radiant

Light Hysteresis

Voltage Hysteresis

at 255 nm

at 194 nm

at 254 nm

at 400 nm

at 633 nm

at 852 nm

at 194 nm

at 254 nm

at 400 nm

at 633 nm

at 852 nm

at +25

°C

at -20

°C

—

140

—

—

—

—

—

0.1

—

1000

—

—

—

—

—

—

—

—

—

—

—

—

—

—

Parameter

Cathode Sensitivity

Anode Sensitivity

Between Anode and Cathode

Between Anode and Last Dynode