Surface degradation of laminated metalRa foils used in school sealed sources in the UK.

In the few years leading up to this research, CLEAPSS noticed a small but steadily increasing number of calls from UK schools regarding a red-brown discolouration on the surface of the foil of their radium source. There were no reports of this type of discolouration on foils of other radionuclides. CLEAPSS and the University of Liverpool collaborated to investigate the nature and cause of this discolouration and the likelihood that the foils were becoming unsafe.

The advantages of creating a positive radiation safety culture in the higher education and research sectors.

The safety culture of any organisation plays a critical role in setting the tone for both effective delivery of service and high standards of performance. By embedding safety at a cultural level, organisations are able to influence the attitudes and behaviours of stakeholders. To achieve this requires the ongoing commitment of heads of organisations and also individuals to prioritise safety no less than other competing goals (e.

Strategies for engaging with future radiation protection professionals: a public outreach case study.

It is evident that there is a nuclear skills shortage within the UK, and logically it can be assumed that the shortfall extends to the radiation protection arena. Plans for nuclear new-build and the decommissioning of existing nuclear sites will require many more people with radiological knowledge and practical competencies. This converts to a nuclear industry requirement in the order of 1000 new recruits per year over at least the next ten years, mainly as new apprentices and graduates.

Evidence for age-related performance degradation of (241)Am foil sources commonly used in UK schools.

The characteristics of alpha radiation have for decades been demonstrated in UK schools using small sealed (241)Am sources. There is a small but steady number of schools who report a considerable reduction in the alpha count rate detected by an end-window GM detector compared with when the source was new. This cannot be explained by incorrect apparatus or set-up, foil surface contamination, or degradation of the GM detector.

A Monte Carlo method to calculate the average solid angle subtended by a detector to an ellipsoidal surface or solid source at any position and orientation.

This note discusses and implements an algorithm for modelling a uniform distribution over a scalene ellipsoidal surface or in a solid so that a Monte Carlo method, suitable for a personal computer, can be used to calculate the average solid angle subtended by a right cylinder or rectangular cuboid detector to the ellipsoidal surface or solid at any position and orientation. The distributions over the surface include 2π and 4π surface sources. The algorithm is developed for truncated ellipsoidal solid and surface sources (where the planes of truncation are restricted to those normal to one of the semi-axes).

A Monte Carlo method to calculate the average solid angle subtended by a right cylinder to a source that is circular or rectangular, plane or thick, at any position and orientation.

This note describes the development of a short program for a personal computer to calculate the solid angle subtended by a right cylinder detector to a circular or rectangular, plane or thick source at any position and orientation to the cylinder. The program also calculates the number of hits on the cylinder side and on each end, and the average pathlength through the detector volume (assuming no scattering or absorption). The current performance of personal computers makes it realistic to model the order of 10(9) simulations of radiation emission and achieve accuracies of solid angle estimates typically better than 0.

The use of a Monte Carlo method to calculate the average solid angle subtended by a detector to source in a non-parallel plane.

In a previous scientific note, a short computer program for a personal computer was described that calculated the average solid angle subtended by a circular or rectangular detector window to a circular or rectangular source in a parallel plane by a Monte Carlo method. This note describes the development of the program for conditions where the detector window is not parallel to the plane of the source, and in particular looks at a method of analysing orientations that relates straightforwardly to practical measurement.

Calculation of the average solid angle subtended by a detector to source in a parallel plane by a Monte Carlo method.

A short computer program is described for a PC which uses a Monte Carlo method to calculate the average solid angle subtended by a rectangular or circular detector window to a coaxial or non-coaxial rectangular, circular or point source. The advantage of the Monte Carlo method is that it allows the calculation of average solid angle for source-detector geometries that are difficult to analyse by analytical methods. The values of solid angle are calculated to accuracies of typically better than 0.

Time-resolved beam structure of an active Q-switched ruby laser.

Time-resolved observations show that the near field and far field patterns of an active Q-switched ruby laser remain almost constant for the duration of the output pulse. This is in marked contrast to the reported behavior of a passive Q-switched laser.