National Physical Laboratory

The National Physical Laboratory is the National Metrology Institute (NMI) of the United Kingdom which has the most experience worldwide in light-ion beam dosimetry. NPL has a strategic interest in light-ion beam dosimetry given the metrology support requested by the proton-therapy community within the UK. NPL’s experience in the field of light-ion beam dosimetry includes the development of dedicated graphite calorimeters, the characterization of ionization chambers and other dosimeters, such as alanine, the development of dedicated phantom materials and the use of Monte Carlo simulations in support of developing dosimetric capabilities

Non-Ionising Radiation

Non-ionising radiation is electromagnetic radiation with insufficient energy to ionise an atom or molecule and therefore cannot cause alterations in the cells of living organisms. Non-ionising radiation is for example: electric and magnetic fields, heat radiation, light and ultraviolet radiation.


Figuratively speaking, photons are what electromagnetic radiation is made of. The term “light particles” is also used frequently. Every electromagnetic radiation, from radio waves to gamma radiation, is quantised in photons. This means that the smallest amount of electromagnetic radiation of any frequency is a photon. Photons have an infinite natural life, but can be produced or destroyed by a variety of physical processes. A photon is never at rest but always moves at the speed of light. Therefore it has no rest mass.

Proton Gantry

A proton gantry is a rotating device allowing the irradiation of a tumour from different directions with a proton beam. It is therefore not necessary to move the area to be irradiated.


The proton (hydrogen ion) is a hydrogen atom ionised by the loss of an electron. It is a building block, like neutrons and electrons, making up everyday matter. Like carbon ions, protons are used in medicine for ion beam therapy.

Radiation Biology

Radiation biology, as an interdisciplinary science, studies the biological effects of ionising and non ionising radiation. It works with molecular, cytogenetic and cytometric methods in different organisms and cell systems. At DNA level, radiation-induced mutagenesis and its repair is being investigated.

Radiation Therapy

Radiation therapy (radiotherapy, radiation oncology) deals with the medical use of ionising radiation on humans and animals to cure disease or retard its progression. As ionising, high-energy beams mainly gamma rays, X-rays and electrons are used. In recent years, plants for treatment with neutrons, protons, and carbon ions have been built. Radiation therapy includes the treatment of benign and malignant diseases.

Secondary Malignancies

Malignancy is a synonym for cancer or a tumour. Secondary malignancies are cancers that arise in the background of another malignancy treated by radiotherapy or chemotherapy.

Secondary Radiation

Radiation generated by the passage of ionising radiation through matter is called secondary radiation. For example in ion beam therapy nuclear reactions with the nuclei of the tissue matter produce highly energetic secondary particles such as neutrons, protons, deuterons, and helium nuclei.


The synchrotron is a circular particle accelerator that can accelerate charged fundamental particles or ions to very high (relativistic) velocities. For acceleration, a suitably synchronised high-frequency alternating electric field (microwaves) is used. In order to keep the particles on a closed track, the magnetic fields of the electromagnets in use need to be readjusted depending on the achieved energy of the particles. To avoid the loss of particles by collisions with gas particles, the particle trajectory lies in a complete vacuum tube system with ultra high vacuum.

Tumour Board

A tumour board is a multidisciplinary tumour committee, where experts from various clinical areas such as surgery, radiotherapy, radiology, and oncology meet at regular intervals to determine the therapeutic method for patients with tumours. With this interdisciplinary review of individual cases, each patient can obtain a tailor-made treatment according to the latest discoveries in medical science.