04/2020 - 03/2024

Raman Absorption and eMission Spectroscopy in an intEgrated Sensor Circular Economy

As a follow-up to the very successful InSPECtor project, Freiberg Instruments is developing a Raman sensor in this project. Together with the partner Helmholtz center Rossendorf HZDR and TU Bergakademie Freiberg and the Geological Survey of Finland GTK, the sensor will be implemented in a spectroscopy-based multi-sensor system for the recycling and re-mining industry. We focus on (1) the development of a Raman sensor unit, (2) the integration into the already developed LiF-HSI sensor system (inSPECtor) and (3) advanced data processing including multi-source data fusion and machine learning.
The core innovation contributes to the digitalization of recycling streams. It allows for the identification of critical raw materials as well as energy stored in plastics as key inputs for simulations of energy and material cycles required for the transition towards a Circular Economy.

Contact person:

Dr. Nadine Schüler (

Automated Lithium-Fluorid OSL Low-Dose-Measurement (ALFON)

2020/12/01 - 2021/11/30

The increasing use of ionising radiation in medical application (CT/X-ray; treatment) and other aspects of modern societies (radiation facilities, power plants), requires the active and passive measurement of radiation. This is paired with more and more stringent regulations on monitoring of radiation exposure and levels. Passive dosimeters are the most widespread and cheapest way to monitor the exposure to ionising radiation of large numbers of people. However, the widely used technique of film dosimetry was replaced by thermally stimulated luminescence (TL), which in turn is now out-phased in personnel dosimetry and slowly replaced by optically stimulated luminescence (OSL). New techniques require the development of new automated measurement equipment, e.g. myOSLraser. Especially dosimetry services, which are handling thousands of dosimeters every day, are faced with large costs of such transitions to new techniques, which are required to keep up with legislation and developments. This is accounted for in the ALFON project by the development of a 4-element OSL-dosimeter, which is shaped like the widespread used Panasonic 4-element TLDs, and thus will allow the  continued use of peripheries for Panasonic TL-dosimetry with UD-readers in existing facilities.

The artificial phosphors BeO and LiF are providing radiation responses close to human tissue and are therefore the material of choice in personnel dosimetry. The project aims to provide dosimeters and measurement equipment exceeding the requirements of EN/IEC 62387, especially on the detection of very low radiation doses. This will be the first commercial use of the new OSL material based on LiF (Sadel et al., 2019), and its favourable properties paired with the possibilities of 4 measurement positions in a single dosimeter, which opens many possibilities beyond the measurement of Hp0.07 and Hp10.

In addition to develop optimized measurement conditions of the new material, the capacities for OSL-measurement are scaled up from the my OSLraser 2-element BeO reader (200 dosimeters), with automations for 500 and 4000 dosimeters. This requires 3-axle feeding mechanisms and a parallel line for dosimeters not meeting user or regulatory specifications, which have to be sorted out for inspection or  re-measurement. The option to measure the same dosimeter again is special in OSL-dosimetry and not possible in TL-dosimetry, thus  fulfilling the legal requirements in some countries..

The 2-element OSL-reader 'myOSLraser' for BeO is used as the basis of the development of the larger 4-element equipment.

Sądel M, Bilski P & Kłosowski M (2019) Optically stimulated luminescence of LiF:Mg,Cu,P with different dopant concentrations. Radiation Measurements 123, 58-62.

Contact person:

Dr. Daniel Richter (

SISor - Sensor for Intelligent Sorting


The separation of waste, especially from electronic and electric devices (WEEE) is a topic, which has drawn a fast-growing interest on a global scale. Due to decreasing availability and rising production costs for raw materials such as rare earth elements (REEs) and precious metals, the mining of secondary resources from waste gained extremely in importance. In 2016, 44.4 million metric tons of e-waste were generated globally, an amount which is expected to increase steadily for the next decades.

Within the SISor (Sensors for Intelligent Sorting) project the core aim is the development of an integrated sensor system for the automated detection of raw materials in the WEEE. An improved detection of valuable materials such as Au, Cu and rare earth elements would strengthen the sorting process of the e-waste, increasing the separation success tremendously. The consortium of the Helmholtz institute HZDR-HIF, the Canadian company Telops Inc. and Freiberg Instruments is going to develop a modular system, containing sensors based on hyperspectral mid-wave infrared (HS-MWIR) absorption spectroscopy and laser-induced fluorescence (LIF) emission spectroscopy. Both techniques are high-sensitive, non-invasive and can be optimized for fast-imaging. Thus, larger streams of recyclates could be processed more accurately in shorter time.

This project is funded by the BMWi.

Contact person:

Dr. Nadine Schüler (

inSPECtor - integrated Spectroscopy Sensor System

The core aim of this project is to gather the respective partner competences to upscale an innovative product based on emission and absorption spectroscopy able to identify and map critical elements as rare earth elements in primary resources as drilling cores and secondary products.

Contact person:

Dr. Nadine Schüler (

Development of measurement equipment for OSL-dosimetry with BeO

2016/03/15 - 2018/09/14

Personnel working in environments with potential exposure to artificial or increased radiation, like hospitals with CT/X-ray equipment, nuclear power plants, radiation facilities, etc., are required to be monitored for their radiation exposure. The availability of film material, which is one of the most important materials in such personal dosimetry, is not warranted on the long term. Other materials have been sought as possible replacements. The dependency of sintered BeO to radiation energy is close to tissue. Because of this favourable property, BeO is one of the phosphors of choice in personal dosimetry. Combined with the technique of Optically Stimulated Luminescence (OSL) for readout, BeO-OSL dosimetry is believed to supersede film dosimetry and at least to some extend thermoluminescence (TL) dosimetry.

The projects aims towards the development of OSL-equipment (EN/IEC 62387) to efficiently read out a new 2-element BeO-OSL dosimeter (Hp07 and Hp10). The modular equipment provides the manual readout of a single BeO-dosimeter. An automation attachment provides the opportunity to measure batches of 20 dosimeters stored in magazines. A total of 10 of such magazines are located in a wheel, which is software driven for dosimeter measurement according to user definitions. In OSL dosimetry it is sufficient to measure part of the signal, which allows re-reading, for dose determination. This usually requires the zeroing before a dosimeter can be used again. Instead of a separate device the bleaching to zero will be achieved within the OSL-reader, which speeds up the process. For calibration purposes a special beta source for irradiation of the dosimeters is constructed. Some application require on-site immediate analysis (e.g. in a phantom) and dose determination. This will be achieved by a single-element BeO-OSL equipment, which is handheld and can be independently operated from batteries, providing immediate dose assessment.


Bos AJJ (2001) High sensitivity thermoluminescence dosimetry. Nuclear Instruments and Methods in Physics Research B 184, 3-28.


2016/06/01 - 2019/05/31

READ - Rare EArth ceramic phosphors for 3D optical readout Dosimetry

Dosimetry for radiation processing applications, as used e.g. in sterilization procedures for medical devices, is often tedious due to the constraints of quality assurance  and fulfillment of the required standards (e.g. ISO 11137, ISO/ASTM 51204, 51608, 51649, …). It is moreover time consuming. As an industrial application it is desired to release irradiated products as quickly as possible.

The project aims at the development of a handheld measurement device, which will provide instant dose information for user defined numbers of dosimeters attached to the product/product pallet, which will allow the immediate release if the specified requirements are met. While this can provide 3-D dose information based on the selected measurement spots, more details are sometimes required for product objects of very complex geometries, where it is essential to verify the dose at positions where dosimeters cannot be attached. For this purpose, a dosimeter material which can be sprayed onto surfaces and measured with a 3D-dose-scanner will be developed.

The dosimetric properties of doped NaYF4 will be employed to develop dosimeters as labels and as spray. These ceramic phosphors exhibit an upconversion effect, denoting the transformation of long-wavelength (infrared or near-infrared) light into short-wavelength radiation (luminescence) with higher photon energy. Here, a dependency of the lifetime of the luminescence with dose (Figure 1) has been shown (Härtling et al., 2012; Reitzig et al, 2013; 2016). This allows the use of a broad dose range of few kGy to 150 kGy (Figure 2). Its high stability under ambient conditions corroborates the application of the material for industrial dosimetry, where the dose information is retained and readout is contactless. These properties make the material a promising candidate for optical dosimetry below 5 kGy, a dose range addressed so far only with more complex non-optical systems.


Christiane Schuster, Florent Kuntz, Alain Strasser, Thomas Härtling, Kay Dornich, Daniel Richter
3D relative dose measurement with a μm thin dosimetric layer, Radiation Physics and Chemistry, 2020,109238, ISSN 0969-806X

High dose dosimetry, Optical dosimetry, gamma irradiation, Electron beam irradiation, X Ray irradiation, ceramic phosphors, luminescence decay time, industrial radiation processing.


Härtling, T., Reitzig, M., Mayer, A., Wetzel, C., Röder, O., Schreiber, J., and Opitz, J. (2012). Nondestructive testing of electron beam sterilization by means of an optically active marker material. In "Optical Components and Materials IX." pp. 825713-825713-6. Proceedings SPIE 8257.

Reitzig, M., Goodband Rachel, J., Schuster, C., and Härtling, T. (2016). Optical electron beam dosimetry with ceramic phosphors as passive sensor material for broad dose ranges. tm - Technisches Messen 83, 171-179.

Reitzig, M., Härtling, T., Winkler, M., Powers, P., Derenko, S., Toro, C., Röder, O., and Opitz, J. (2013). Time-resolved luminescence measurements on upconversion phosphors for electron beam sterilization monitoring. In "Smart Sensor Phenomena, Technology, Networks, and Systems Integration." (K. J. Peters, W. Ecke, and T. E. Matikas, Eds.), pp. 86930R-86930R-7.

Mr. Florent Kuntz