Beckhoff BX3100 bus terminal controllers and CX1000 embedded PCs, for which Hayes Control Systems is the exclusive UK distributor, are playing a vital role in a ground-breaking proton irradiation system which promises to provide a much more effective alternative to conventional radiotherapy in the treatment of cancer.
Unlike conventional X-rays, proton beams release their energy at a controllable penetration depth within cancerous tissue, and are much less susceptible to undesirable scatter. This means that higher energy densities can be achieved within the affected tissues, leading to an increased probability of curing the disease.
The first European installation to take advantage of these benefits has recently been brought into operation in Munich. At its heart is a cyclotron particle accelerator, which accelerates protons until they reach 60% of the speed of light. When they have achieved this speed, they are deflected by an electromagnetic field.
To target the resulting beam precisely at the required location within the cancerous tissue, 182 deflection and guide units are used.
The proton beam travels within an evacuated 160m long stainless steel tube system and, for monitoring the vacuum in this tube, five independent systems are used. All of these are controlled via Beckhoff BX3100 with Profibus interfaces. BX3100 communication terminals, together with KL6001 serial interfaces, are used for data acquisition.
The deflection and guide units used for beam targeting employ special electromagnets that are controlled via high-precision variable power supply units. Ten Beckhoff CX1000 embedded industrial PCs, each with two RS422 interfaces, provide continuous communication between the control system and the electromagnet supplies.
"The cycle time for data packets exchanged between the CX1000 PCs and the power supplies is just 2ms, which means that very fast calculations and also very high data throughput are needed," explains Mark Bates from Hayes Control Systems. "The ability to consistently meet these requirements was one of the key factors in the decision to use Beckhoff technology."
Uwe Behrens, a consultant for Accel Instruments, the company that supplied the control and measuring equipment for the project, says: "The excellent integration of the hardware and software supplied by Beckhoff has been very important to us and to the end user. There's no doubt that the support and advice we received from Beckhoff has played a big part in the company's success.
