Hamamatsu R6095 photomultiplier tube

I’ve bought this R6095 PMT tube from iRad ebay seller. It cost me about 40$ plus shipping. iRad sells it as just tube or with socket and voltage divider kit. I’ve bought the complete kit.  A link to his auction: iRad

R6095 PMT from iRad
Minimum Wavelength 300 nm
Outside Diameter 28 mm
Peak Wavelength 420 nm
Maximum Wavelength 650 nm
Viewing Direction Head on
Rise Time 4 ns
Photocathode Material Bialkali
Window Material Borosilicate
Anode Current 0.1 mA
Typical Photocathode Luminous Sensitivity [µA/lm] 95
Photocathode Peak Radiant Sensitivity [A/W] 0.088
Gain 2.1 x 106
Max. Supply Voltage Between Anode and Cathode 1500 VDC
Max. Supply Voltage Between Anode and Last Dynode 250 VDC
Operating Temperature -80 to +50 °C

This tube could be used to make a nice scintillation probe coupling it with a 30mm diameter NaI(TI) crystal and feeding 800-900V. Yes… just 900 and you can expect a gain of 10^6. Within the box there is the datasheet of the tube plus an instruction sheet to wire the voltage divider network to the socket.

Tube plus socket and instructions

SI-19BG(M) си19бг-м mini Geiger tube

I’ve bought this cute mini Geiger tube from eBay. It’s cheap… in the order of 10-15€. The interesting thing about this tube is it’s size: 20mm lenght per 9mm diameter that makes it a good choice to make a portable dosimeter.

SI-19BG-M geiger tube

It’s sensibility is not hight but is better than SI-3BG. Another cool thing is it’s glass window. People around internet say that is a mica window for alpha particles but, I’ve testd it in contact with a piece of pechblende that, is a strong alpha+beta emitter sample and I’ve seen that it’s count rate is so small… like it ounts just beta+gamma.

SI-19BG window

Tech info:

  • Sensitivity: 1000-1500 Pulses/s/R/h
  • Plateau inclination: 0.25%/V
  • Working voltage: 360-440V
  • Maximum registering range: 900 Roentgen/hour
  • Lenght: 20mm
  • Diameter: 9.3mm
  • Weight: 4 grams

I’ve found on eBay a photo from a seller that sold it with it’s original connector… looks more an enclosure/socket than a connector.

SI-19BG connector

MST17 MCT17 Mica window Geiger tube

Searching for an alpha-sensible Geiger tube to buy, you’ll find for sure some Si8B and SBT11 pancale style tubes. This are great tubes but… if you found this MST17? It’s not a military surplus pancake tube, is from the professional series “M”. You must know that russian tubes that name starts with “M” are made for professional and scientific use. Usualy are made in glass and are fragile, they need higher voltage to operate but…. they are true scientific tools not cheap surplus!

MST17 Geiger tube

This is the MST17 tube, a professional tube used by russian in professional scientific equipment. Is cheaper than other mica windowed tubes because il hard to use. It need 1600V in order to operate. It was used to measure milk nuclear contamination after Cernobyl disaster in contamined ukrainian zones.

MST17 Front cap

The tube have a metal cap to protect the mica window and to filter out most od Alpha particles, i say “most” and not all because it have a small hole in the center. The mica window is not so thin so I think this tube is more suitable to beta and gamma use.

MST17 Mica window

I’ve found some other infos about this tube:

Tech. spec.:

  • Radiation determine: 
    1. Alpha *
    2. Beta (>0.16Mev)
    3. Gamma

*- the distance between source and mica window must be 25 mm or less (for alpha radiation only).

  • Voltage of start of counting: < 1600V
  • Operating voltage (recommended): 1620 – 1740V
  • Length of flat part of counting curve (plateau):  150 V
  • Slope of the counting curve:   < 0.05%
  • Own background:   < 0.41 counts/s
  • Maximum radiation: 10,000 counts/min
  • Load resistance: 7-10 MOhm
  • Allowable stray input capacitance: < 10 pF
  • Working temperature range: -30…+50 C
  • Anode material: Platinum
  • Mica window thickness: < 5 mg/cm2
  • Weight: ~20g
  • Dimensions: counter length 100mm, diameter 40mm
  • Mica window diameter: 20 mm.
DP100 milk dosimeter

The DP100 russian scientific instrument use the MST17, enclosed into a lead chamber to reduce background radiation, to mesure milk contamination.

CHERNOBYL ACCIDENT” there is a physical modelling and mathematical analysis of this device.

Random “Walker”

This program simulate the random motion of an object, the “walker”, that is governated by the trow of a dice. Face one? Go une pixel up. Face two? Go une pixel left, exc. I’ve implemented it first in Processing language following “The nature of code” book’s introduction. I sugest you to buy your copy http://natureofcode.com/ if you find interesting the simulation of nature (fractals, randomness, physics simulation, exc…). Finaly I’ve made a traduction of the code for mbed compiler. Now it runs on STM32F469-Disco board because of his very nice LCD display.

This is the mbed source code: main

All the needed include files to compile it in mbed are avaiable from mbed. Just select the proper board and create an LCD demo project. Then, copy the dependencies from the demo project files to your project and copy the content of the “main” link in your project’s main.cpp. More info in my video.

If you use Keil uVision 5 compiler here the project, complete: Walker_uvision5_disco_f469ni

Here how it works in Processing.

In this video you can see the program at work and his explanation.