MAXIMUM RATINGS (Absolute Maximum Values)

Parameter

Value

Supply Voltage

Between Anode and Cathode

Between Anode and Last Dynode

1250

250

0.1

–80 to +50

Vdc

Vdc

mA

Average Anode Current

A

Unit

Ambient Temperature

CHARACTERISTlCS (at 25

)

NOTES

Parameter

Min.

Typ.

Typ.

Max.

R2693

for General Purpose

R2693P

for Photon Counting

Cathode

Sensitivity

Anode Dark Current

E

(After 30min. storage in darkness)

Anode Dark Counts

E

Anode

Sensitivity

0.5

5.0

Anode Current

K

Stability

A:

B:

C:

D:

E:

F:

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 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

voltage distribution ratio shown in Table 1 below.

Measured with the same supply voltage and voltage distribution

ratio as Note D after removal of light.

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 minutes 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

wavelength of peak response.

G:

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 amplitube. In

measurement, the whole photocathode is illuminated.

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

transit time between individual pulses in the single 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

0.5

1.0

Radiant at 375nm (Peak)

62

Blue

C

7.0

Anode Pulse Rise Time

G

1.2

Electron Transit Time

H

18

Transit Time Spread (FWHM)

J

1.0

Time Response

D

Quantum Efficiency at 375nm

30

50

20.5

Gain

D

ENI(Equivalent Noise Input)

F

Unit

PHOTOMULTlPLlER TUBES R2693, R2693P

Luminous

B

Radiant at 375nm

3.7

Luminous

D

300

100

8.6

Min.

Max.

0.1

2.0

nA

0.5

1.0

%

%

62

mA/W

7.0

A/lm-b

1.2

18

1.0

ns

ns

ns

30

50

A/lm

20.5

%

3.7

A/W

300

A/lm

100

6

6

15

50

cps

3.9

W

(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.

Electrodes

R2693

K Dy1 Dy2 Dy3

Dy9

P

Ratio

1

1

1

••••

••••••••

11

SuppIy Voltage : 1000Vdc, K : Cathode,Dy : Dynode, P : Anode

Electrodes

R2693P

K Dy1 Dy2 Dy3

Dy9

P

Ratio

2.5 1.5

1

••••

••••••••

11

Table 1:Voltage Distribution Ratio

Hysteresis =

100(%)

lmax.

li

lmin.

TPMSB0002EA

TIME

max.

l

min.

l

i

l

0

5

6

7 (minutes)