MAXIMUM RATINGS (Absolute Maximum Values)

Parameter

Value

Unit

Supply Voltage

Ambient Temperature

Vdc

Vdc

mA

°C

2500

500

0.2

-80 to +50

Between Anode and Cathode

Between Anode and Last Dynode

PHOTOMULTIPLIER TUBES R331, R331-05

CHARACTERISTICS (at 25

°C)

Table 1: Voltage Distribution Ratio

Parameter

Min.

Unit

Cathode

Sensitivity

Anode

Sensitivity

Anode Dark

Time

µA/lm

%

mA/W

µA/lm-b

A/lm

A/W

—

cpm

cpm

ns

ns

ns

60

—

—

9.0

30

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

Max.

Typ.

90

25

85

10.5

120

1.1

1.3

16

18

2.6

48

1.1

Quantum Efficiency

at 390nm

Radiant at 420nm

Radiant at 420nm

R331

R331-05

NOTES

A: Averaged over any interval of 30 seconds maximum and

the whole photocathode is illuminated.

B: The light source is a tungsten filament lamp operated at

a distribution temperature of 2856K. The light input is

0.01 lm and 150 volts are applied between the cathode

and all other electrodes connected together as anode.

C: 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.

D: Measured with the same light source as Note B and the

light input is 0.1µlm. The anode-to-cathode supply vol-

tage and voltage distribution ratio are shown in Table 1.

E: Background noise after 30 minute storage in darkness.

F: The rise time is the time for the output pulse to rise from

10% to 90% of the peak amplitude when the entire pho-

tocathode is illuminated by a delta function light pulse of

400nm.

G:

The electron transit time is the interval between the

arrival of a delta function light pulse at the input window

of the tube and the time when the output pulse reaches

the peak amplitude. In measurement the entire

photocathode is illuminated.

H: Also called transit time jitter. This is the fluctuation in

electron transit time between individual pulses in the

single photoelectron state, and may be defined as the

FWHM of the frequency distribution of the transit times.

Supply Voltage: 1500Vdc, K: Cathode, Dy: Dynode, P: Anode, G: Grid

* Shield should be connected to Dy5.

Electrodes

Distribution Ratio

K

G

Dy1

4

Dy2

0

Dy3

1

Dy4

1.4

Dy5

1

Dy6

11

1

1

1

1

P

Dy7 Dy8 Dy9 Dy10 Dy11Dy12

111