USES OF X-RAY

Nelson Evening Mail, Volume LXVI, 19 August 1933, Page 3

USES OF X-RAY

TWO HUGE PLANTS CLINIC INSTALLATION EMPLOYMENT BY ENGINEERS Since th? .discovery of the, X-ray in 1595 by Wilhelm, Rontgen; the application of his knowledge has, been extended to the fields of medicine, dentistry and engineering,. . • , ' The Announcement'.of a grant from a Christchurch estate for the purpose of special investigation into the most modern ' therapeutic use'and uses of Xray and radium comes at a time when Chicago is placing before the world, two outstanding examples of the magnitude of the X-ray (reports thp Auckland “Star”). One plant is for clinical purposes, and is an 800,000-volt unit. The other is the display of the tremendous undertaking of producing 75 miles of radiographs of the seams in a penstock tunnel. At the Mercy Hospital, Chicago, the installation of tlie greatest X-ray plant in .tlie' world was completed three months ago. IF marks a notable advance‘in the' battle of medical science against cancer. Built to operate continuously at its conservatively" rated capacity of 800,000 volts and 10 milliamps, the apparatus exceeds by 100,000 volts the working voltage of any otlfer installation "known to be in regular operation, and has a current capacity twice as groat as any other X-ray tube and machine, in the world. It is calculated that tlie radiation from the apparatus is equal in quantity to the radiation from £15,000,000 worth of radium at current prices for radium salts.

FOR CANCER TREATMENT In .the opinion of Dr Schmitz, one of the pioneers of radiation therapy in the United States, the X-ray is the economic solution for the treatment of large and deep-seated cancer tissue. He says: “Radium radiations lose very rapidly in intensity as the distance betwen the radium and the body is increased, because the ’ radiations are • diffused in, the' air, With the X-ray. tube, however, the" initial intensity is very great, and loss by diffusion is relatively slight'. The direction of the rays from their source may he controlled by using long distances between tlie tube and the patient, arid a series of beams directed diagonally toward the tumor. Thus by a summation of tlie energy .of several successive beams the dose in the tumor surpasses the dose received on any area of the skin surface.” ... . - • Tlie building in which tlie apparatus is installed is constructed specially for the safe employment of radium and X-ray. It is 03 feet long, 32 feet wide and 30 feet High. Over 40 tons of lead were used in the construction for protection against the cumulative eeffets of the X-rays upon those who are constantly working in the laboratory. The room in which the patient is placed is lined with 22 tons of lead. The giant X-ray tube is. 1-1 feet long, and is in

two sections, built by Dr D. W. Cool' idge and his associates. AUTOMATIC SAFETY DEVICES Through a periscopic _ device the operator lias the patient in full view during the treatment, and may converse with him through the same, pfihbipg. Automatic safety devices throughout the installation are prominent features. If the door to the patient’s treatment room is opened the X-ray is automatically cut off; it is also nut off if the door to the high-voltage room is opened for tlie “dose” is pre-determined, and automatically indicated by a. device in front of the operator at his controls. * Thus there is a constant check on the dosage while the tube is working. A TRAVELLING UNIT " | In the realm of,metallurgy the X-ray is becoming indispensable. The greatest undertaking of X-ray service jjn engineering is that performed by the minute examination of the seams of the huge penstock tunnels for the Hoover Dam, for the waters of the' Colorado River. Every inch of fusion welded seam in these tubes is being .checked over by a travelling, unit using 300,000 volts. . ..: The contractors agreed to this radiographic inspection of all fusion welds, which involves a distance of 75' miles of X-ray photography. Here are some of the requirements:. Longitudinal and circumferential welds up to \3in thick, in penstock sections;ranging, from B|ft to 30ft in diameter must he radiographically inspected. .(To accomplish this, more .than 159,000 separate X-ray exposures must, he made, involving tlio use of more than 24,000,000 square- m dies of X-ray film. X-ray facilities must be such that exposures can be made conveniently, rapidly, accurately, safely and consistently. IMMERSED IN OIL ' V

To comply with this last clause the manufacturers supplied an .equipment with its complete high-tension systemtransformers, condensers, Kenotroiis and X-ray tube—completely immersed in oil arid sealed within a compact tarik Tlie rays can be - quickly ' directed at any angle requiored.Tliere is no possibility of accidental shock from the high tension, as the only external wiring is at low tension. The complete Unit travels on rails along ' turinds, and is an Invaluable insurance against faults in a.ihuge And expensive hydroelectric system.