What is ISP?

The Ionising Radiation Laboratory (Dutch acronym: ISP) is part of Utrecht University and offers a hands-on practical on ionising radiation – specifically radioactivity and X-ray radiation. These sessions are primarily intended for final-year high school physics classes (HAVO and VWO).

The reasons for offering the ISP as a centralized facility for secondary schools are twofold. First of all, schools generally do not have the financial means to invest in the rather expensive radioactive and X-ray sources and measuring devices, and in the necessary permits and prescribed safety precautions. Secondly, without such a facility the teaching of the topic of ionizing radiation would be of a mainly theoretical nature, while the students’ hands-on experiences could positively influence their motivation and conceptual development concerning this socially relevant topic. The ISP was established to enable schools to give students safe, practical experience with this otherwise abstract topic.

The ISP owns three mobile laboratory facilities with twenty-two experiments. These experiments can be installed in a standard school laboratory for one day (or longer, if necessary). In addition, the ISP owns a comparable permanent laboratory with a regional function, located at Utrecht University.

When we bring a mobile set to your school, we arrive by car carrying the twenty-two experiments, set them up in a classroom, supervise the practical during the day, and take everything with us again afterwards.

• The practical lasts a maximum of 120 minutes, during which students perform two to three different experiments.
• During such a session, they are coached by the ISP staff member and their own teacher or the school’s laboratory technician.
• With enough setups available, classes of up to 32 students can participate simultaneously.
• We can provide up to three sessions a day. When there are more than 96 students, we can schedule two (or even more) days.
• The experiments are divided into three categories:
  • Half-life
  • Absorption
  • X-ray and miscellaneous

Because students perform experiments from two or three different categories, they experience a broad range of aspects of ionising radiation.

Registration

• Register for the mobile practical (we come to your school)
• Register for the fixed practical (you bring the students to the university)

The Variants

Nowadays, the practical can be conducted in two different variants, which are both available in English. Both the fixed and mobile practicals can be carried out in a closed variant and an open variant. The difference lies in the type of worksheets the students use:

• In the closed variant, the worksheets guide the students step by step through the measurements and processing of the results.
• In the open variant, students design their own work plan for conducting the experiment. Here, the detailed step-by-step instructions are omitted.

Some of our experiments, due to their qualitative nature or the complex processing of measurement results, are not suitable for an open variant.

Preparations

For the practical, students can preview the experiments and review the information booklet in advance. We recommend that students at least read the introduction and the section on radiation safety beforehand. Which can be downloaded below and on the student section of this website. The practical leaders will bring several physical copies of the booklet, but you may also choose to print additional copies yourself so that each student has their own booklet.

Open variant

When students are going to conduct an open experiment, it is advisable that they prepare a work plan in advance. They can prepare the open experiment in their own time outside of class and discuss the results with the teacher, who will evaluate them and address any necessary adjustments with the students. Such a work plan discussion takes about 10 to 15 minutes. Compared to the closed version of the practical, the open variant also requires a significantly larger time investment from the teacher during preparation, because the students’ research question, hypothesis, and associated measurement plan must be evaluated and discussed. If this is not done, or done insufficiently, problems may arise during the practical: students may not know what they are supposed to do. Under the constraints of limited time and class size, such issues can only be resolved by telling the students what to do, which defeats the purpose of an open variant.

For the evaluation and discussion of students’ submitted work plans, a second, one-time time investment is needed from the teacher: developing a clear understanding of the goal and possible execution of each experiment. This preparation is essential to properly assess the students’ work plans for feasibility and completeness. This preparation can be done using the worksheets from the closed variant and a number of instructions per experiment available on the student section of this website. This necessary preparation for the work plan discussions is the reason that the open variant should only be chosen if the teacher has a reasonably good familiarity with the ISP experiments.

Closed variant

When students only conduct closed experiments, they may decide on the spot which experiment to perform. Once they have finished that experiment, they can choose another free experiment from a different category (colour). This system prevents students from having to wait for a group still working on an experiment, or from being forced to give up their setup before finishing. In the information booklet, students can already browse the different experiments and get an idea of which ones they find most interesting. If you would still prefer to make a plan in advance, you can create a rotation schedule.

If it has been some time since students last had lessons on ionising radiation, it is recommended to refresh their knowledge beforehand. Core concepts such as activity, half-life, range, and half-value thickness are particularly important.

All information relevant for students in preparation for the practical can also be found on the student section of the website.

Information Booklet and Worksheets

• Download Information Booklet
• Download Worksheets [closed experiments]
• Download Worksheets [open experiments]

The passwords for the Worksheets can be obtained via the visiting staff member or by writing an email to science.isp@uu.nl

Information Sheets

1 Range of Alpha Particles in Air
5 Universal Range
6 Geiger-Müller Tube

Financing

The ISP is financed to a large extent by the Dutch Ministry of Education, Culture and Science supplemented with incidental contributions from the University of Utrecht. In addition, the Dutch schools for secondary education pay in school year 2025/2026 a fee of €9,- for each participating student with a minimum of €270,- for a school visit by one of the mobile laboratories.

Contact information

The ISP is an initiative of the Freudenthal Institute for Science and Mathematics Education at the University of Utrecht, currently supported by the Julius Institute at the Department of Physics and Astronomy.

The information about the ISP on the Dutch part of this website is summarized below. In case of further questions (and difficulties with reading Dutch), you can contact us in one of the following ways.

Staff members

Dagmar Jongenelen
Jeroen de Meij
Laura van Leeuwen
Rob van Rijn (coordinator)