MATROSHKA Instrumentation


The MATROSHKA facility basically consists of a human phantom upper torso, a Base Structure and a Container with a total weight of about 65 kg. The container as well as the phantom torso are mounted to the base structure which serves as a footprint for the human phantom. The container is a Carbon Fiber structure and forms with the Base Structure a closed volume that contains a dry oxygen atmosphere at ambient pressure and protects the phantom against e.g. space vacuum, space debris, solar UV, and material off-gasing. It acts also as a simulation of the space suit. The phantom body is made of commercial phantom parts, well introduced in the field of radiotherapy. It consists of 33 slices composed of natural bones, each with a thickness of 25 mm, embedded in tissue equivalent plastic of different densities for tissue and lungs. The Phantom slices are equipped with channels and cut-outs to allow the accommodation of active and passive dosemeter systems as well as temperature and pressure sensors (Housekeeping data). A total number of six temperature sensors, three of them in the phantom torso in the slices # 2 (head), #16 (upper torso) and #26 (lower torso) and three in the base structure as well as two pressure sensors allow the observation of the temperature and pressure profiles in the facility. Besides the dose determination inside the body the torso is also equipped with a Poncho and a Hood for skin dose determination. The cables indicate the positions of the Plastic Szintillation detectors (SSD) inside the body. The Silicon Telescope DOSTEL is mounted atop of the Head, whereas the Tissue Equivalent Proportional Counter (TEPC) is mounted in front of the upper body on the base structure.

The 33 slices of the phantom are equipped with 356 channels where the TLDs from the participating groups are located at a total number of 1634 positions arranged in a way that the TLDs are positioned in a one inch grid at each of the slices. The TLDs are located in tubes with tissue equivalent spacers. At each of the 1634 points a minimum number of 6 up to 12 TLDs made out of different TLD materials (e.g. a combination of TLD 600 (6LiF:Mg, Ti), TLD 700 (7LiF:Mg, Ti) and TLD 700H (7LiF: Mg, Cu, P) are located. This allows besides the determination of the absorbed dose also information about the thermal and epithermal neutron dose using the pair method.

Besides the TLDs in the 33 slices the Phantom has five cut outs where so called NTDP (Nuclear Track Detector Packages) packages are installed. These cut outs enable the positioning of the NTDP packages with an inner dimension of 55 x 35 x 21 mm in five slices measuring the dose in the eye, lung, stomach, kidney and intestines. These boxes are equipped with a combination of TLDs (total number of TLDs per box : 60) and CR-39 detectors, where the CR-39 are arranged in three orthogonal directions to enable LET and particle spectra in the x, y and z axes. Further on the packages contain CR-39 detectors covered with converter foils to account for the neutron organ doses.

The Torso is equipped with a Poncho and a Hood. The Poncho and the Hood are equipped with polyethylene stripes with sewed in TLDs (around the whole torso) to measure the skin dose. Further on the Poncho is equipped with six NTDP packages in similar dimensions as in the organs (two in front, two in the back and one on each side of the torso) to measure the skin dose.

Atop the phantom head a NTDP as well as the Silicon Telescope DOSTEL are located. Inside the torso – in the organ dose slices – besides the NTDP packages active Silicon Szintillator Devices (SSD) – a plastic szintillator covered with silicon diodes with anticoincidence to measure the neutron dose - are positioned.

The Carbon fiber glas container of the facility is covered with a Mulit Layer Insulation (MLI) for thermal control. At the MLI five packages are mounted (three at the front and two at the back). These packages contain passive TLD and CR-39 experiments for the determination of the depth dose.

The HAMLET project is funded by the European Commission under the EU’s
Seventh Framework Programme (FP7) and coordinated by the
German Aerospace Center (DLR)

Site last modified: Friday 24 October 2014, 12:52