[proxy] www.crtsite.com← back | site home | direct (HTTPS) ↗ | proxy home | ◑ dark◐ light

The Cathode Ray Tube site, X-Ray tubes.

Ion X-Ray tubes
The second page

          William David Coolidge 1873-1975

Triple cascade X-ray tube in the lab of Dr. Coolidge 1928
In this lab model every bulb is fed with 300KV, the tube was 2,4 meter long with bulb diameters of 30cm!

Lodge X-ray High Tension Valve ca 1912
This rare rectifier tube invented by the physicist Sir Oliver Lodge prevented reverse currents which occurred using Ruhmkorff coils. The inversed voltage had a negative effect on the pressure in the Ion tubes. These rectifier valves prevented these inversed voltages. The valves were used in series with the X-ray tube.
The Cathode inside the tube is an aluminum spiral which creates a larger surface for handling high currents. The distinctive red colored glass is the result of a specific exhaustion method which keeps the vacuum stable under all conditions.

Pictures courtesy of Alastair Wright.

From Ion X-ray tubes to Hot Filament tubes

  In the early times Crookes or Hittorf tubes consist of a few simple electrodes projecting into a
  glass bulb. With one of these tubes Wilhelm Röntgen made his discovery for which he was
  awarded for the first Nobel Prize. The classic cold cathode ion X-ray tube was born. A tube with two
  electrodes. The tube developed qiuck into a three electrode tube with an anticathode and platinum 
  target (due to the high melting point of  this metal).
  Soon after the discovery of Conrad Röntgen the production of these tubes started, not only in the
  German factories of Gundelach, Müller, Pressler and Siemens. But also Andrews in England.
  In the US by Victor and General Electric. But these ion tubes had many disadvantages like unstable
  vacuum and cooling. Some described them as unpredictable as a woman.

  The great breakthrough came in 1913 when William Coolidge and Lilienfeld made there first hot filament
  cathode X-ray tube, he replaced the cold cathode with a heated spiral filament cathode and tungsten
  anode. The third anticathode disappeared, the angle of the anode in his tube was set at 45º. X-rays
  could now be better controlled and were more reliable. The only practical problem was cooling the
  Anode, (which got extremely hot) this was a huge problem due to its small size. New designs were
  developed, a heavy copper base to the anode, sometimes with water or air cooling, this conducted the
  heat away and therefore increased the capacity of the tube to withstand a high current.

  Philips developed in 1924 the Metalix tube. The glass tube was fitted in a metal housing and also
  incorporated the principle of line focus. This tube had sufficient shielding for physician and patient and
  was safe to use with the high voltage.
  The anode face was changed to an angle of 19º in respect to the cathode.

X-ray demonstration tube for Gaede pump use.
Leybolds Nachfolger 1910-1930
This tube has blue glass terminals.

Picture from the Leybolds Nachfolger catalogue 1911.
Leybold sold many types of tubes for the use on a
Gaede vacuum pump.

This picture comes from the Leybolds Nachfolger catalogue from 1929.
In this catalogue the tube is only printed in combination with the Gaede pump and not available anymore as a separate item. The reference number points at a new type. This dates this tube before 1929.

Another X-ray demonstration tube
for use on a Gaede pump.
ca 1910-1930  Height 30cm

Like it? Sign the Guestbook!

Didactical and Toy X-ray Tubes

Rectifier Valves

Hot filament Coolidge X-Ray Tubes

  Glass
blowers

Traders

Tube
 info

With a bulb diameter of only 4,5cm dates from early 1900. It was probably part of a German experiment box sold by Bing or Meiser&Mertig

Advert from the Bing 1912 toy catalogue.[62]
Around 1900 many educational different Physics boxes were sold for amusement or Christmas gift. Many kids were experimenting with the newly discovered techniques like electricity and even X-rays without warning!

Home entertainment X-ray tubes.

  These rather small X-ray tubes were used in school and for  
  home entertainment sold as part of Physics
  experiment boxes together with small Ruhmkorff coils or
  Wimshurststatic machines. The drawings from the
  original catalogues show how the set was used.

Page from the 1909 German
100 Schülerexperimente
von Dr. C. Richard Schultze.[58]

Activated tube

Small Gundelach Ion tube for school demonstrations ca1910
On the sphere there is a J etched, this was used by Gundelach for marking tubes made for rectified alternating voltages, probably for use with the "Ideal Apparat" made by Reiniger Gebbert & Schall.

Smallest working X- ray setup ever seen, sold for child use!

Working tube on the smallest
German coil I know.
Due to it's age the tube is gassy
and no harmfull x-rays are produced.

A small 15cm fluoroscope screen made by the German company Heyden ca1910, an Ampere meter made by the French maker C.G de Radiologie and an English indicator tube ca 1910.
The indicator tube was placed in series with the X-Ray tube to see if there was a reverse current present.

The working of an indicator tube shows the typical reversed current of a Ruhmkorff coil, Ionisation around both wires, there is a bit more forward current than reversed. Due to this phenomena most early X-ray tubes degraded and eventually were not useful anymore.
Placing a valve tube in series with the X-ray tube prevented this negative effect. With a true DC current only one wire will ionize.

Fluoroscope
A viewing device with a fluorescent screen in the front.

X-ray tube ca 1910 likely from the French Gaiffe & Pilon company. Bulbsize 15cm.

A complete toy X-ray setup from early 1900 with a 5cm X-ray tube
In front a German DIY X-ray booklet for kids.

An indicatortube made by CHF Müller.

Stages of hardness
Glass makers added manganese dioxide to the glass for the distinct green fluorescence which helped the x-ray operators to judge the correct hardnees for optimum results.

                         X-ray tube production in England
  Cuthbert Andrews (1882-1972) was a leading English manufacturer of X-ray 
  tubes in the early days. C.H.F Müller a large German X-ray tube maker, 
  wanted to produce and sell X-ray tubes in Britain. In 1909 Andrews
  came in contact with Mr. Müller and by 1912 Andrews started producing X-ray 
  tubes for the English market. Andrews his company was virtual the only 
  manufacturer of conventional X-ray tubes in Britain after 1930.
  His company produced over more than 30.000 tubes of 75 different shapes. 

  This text is extracted from an article which can be found on site of RHHCT.

The Cathode Ray Tube site  
150 years of  CRT evolution
The Dutch collection

HOME

 CRT

 X-ray
 tubes

Geissler
  tubes

Crookes
  tubes

Induction
    coils

Camera
 tubes

Info
page

The set sold by Radiguet