My projects at a glance

Transcription

1 My projects at a glance Michał Gumiela Student at The Faculty of Computer Science, Electronics and Telecommunications AGH University of Science and Technology in Cracow October 31, 2013 Abstract The article is about two of my technical and scientific projects carried out during my secondary school. It contains short descriptions of my scientific works related to measurements of ionising radiation and the mission of the KrakSat s model of planetary probe. 1

2 Contents 1 Introduction 3 2 The KrakSat mission - building a CanSat planetary probe About CanSats The KrakSat Team About our CanSat Sensors Results CMOS and CCD image sensors as ionising radiation detectors The Aims How it works? Used detectors Detection of different types of ionising radiation Summary

3 1 Introduction All my works I have done are reflections of my interests. Since I started secondary school I am mainly interested in electronics, physics and computer sciences. In my projects I am trying to combine all mentioned fields of science e.g. creating the electronic devices and software for physics measurements. 2 The KrakSat mission - building a CanSat planetary probe 2.1 About CanSats A CanSat is a type of sounding rocket payload used to teach space technology similar to the technology used in miniaturized satellites. No CanSat has ever left the atmosphere or even orbited earth.in CanSat competitions, it s required to fit inside of a soda can (66mm diameter and 115mm height) and have a mass below 350g. The CanSats are deployed from small rocket at height which varies depending on the competition. Source: en.wikipedia.org/wiki/cansat In the case of ESA CanSat Competitions 2013 the height of deployment was 1 km. 3

4 CanSats are equipped with a recovery system, usually a parachute, to limit damage upon recovery and to allow the CanSat to be reused. CanSats are used to teach space technology, because of their inexpensive price and small volume. Source: en.wikipedia.org/wiki/cansat Figure 1: All CanSats of European CanSat Competitions 2013 European CanSat Competitions 2013 The competition was held in the Netherlands, from 10th to 14th April It was the third European CanSat campaign. After months of preparations, 12th April was the day of the launch, the day when 15 student teams from 8 different ESA Member States had an opportunity to carry out their own space-related experiments. The rockets had been prepared by T-Minus Engineering Team with ESA cooperation. But due to technical problems only 12 out of 15 CanSats were successfuly deployed from the rockets. The day after launch campaing was the day of the results of presentations. 4

5 2.2 The KrakSat Team The team consisted of eight secondary school students from Andrychów and Cracow. Each member of our team was a specialist in a particular field. Combining ours all skills we made a very strong team and finally we won the competition. I was a team leader as well as hardware and software (mainly LabVIEW) designer. PhD Aleksander Cianciara supervisor Michał Gumiela team leader, hardware and software designer Grzegorz Gajoch hardware and embedded software designer Łukasz Gurdek software designer Michał Zieliński software designer Bartosz Dziewoński software designer Mateusz Cianciara hardware designer Antoni Odrobina modeler Ewelina Badak public relations 5

6 Figure 2: The KrakSat Team. Starting from left: PhD Aleksander Cianciara, Łukasz Gurdek, Michał Zieliński, Antoni Odrobina, Ewelina Badak, Mateusz Cianciara (in the back row), Michał Gumiela, Grzegorz Gajoch (in the back row) and Bartosz Dziewoński. 2.3 About our CanSat We were building a planetary probe. We wanted to find out if a human could survive on explored planet and how dangerous it would be. We aimed to collect data about various parameters during the fall and the landing. 6

7 Figure 3: Our CanSat (without carbon fiber case) charging before second launch. 2.4 Sensors Ionising radiation sensor Primarily, we wanted to measure the level of ionising radiation, which is dangerous for human beings. Radiation level data is necessary to construct a proper shield against the particles; it may also help determine if life can exist on this planet. As a detector STS-5 Geiger tube was used. UV radiation sensors UV radiation causes skin cancer. It s emitted by stars so it s required to know level of UV radiation. The intensity of UV radiation can be calculated using following formula: for the first sensor: I(D UV1 ) = D UV [ ] W m 2 for the second sensor: I(D UV2 ) = D UV [ ] W m 2 where D UV1 and D UV2 are digital values from ADC. 7

8 Humidity sensor Measurements of humidity level allow to determine amount of water available in the atmosphere for astronauts and plants in the future missions. Water spreaed in the atmosphere is easy to collect. Light sensor Visible light sensor measure photons in visible range. It s necessary to plants grown and human too (seeing, good frame of mind). Temperature sensors Two different sensors of temperature were mounted in the CanSat. It allowed us to measure differences in temperature high above the ground as well as after landing with better reliability. One of ours sensors can measure temperatures from range of 10 K 293 K. Temperature in Celsius degrees from the first sensor can be obtained using following equation: T(D T1 ) = D T [ C] where D T1 is raw, digital data from sensor. Temperature from the second one can be calculated using such a formula: T(D T2 ) = D T ( 372, 1) + 169, 17 [ C] where D T2 is raw, digital data from sensor s ADC. Telemetry Accelerometer, pressure sensor, magnetometer, gyroscope were used for telemetry and measurements of planet s parameters. 2.5 Results The mission was successful. We can say that we have reached all goals developing such a thing gave us a lot of fun. We have learnt a lot of new things and now we have an experience in group working. Some of the results are shown on following graphs: height vs. time, velocity vs. time, acceleration vs. time, intensity of UV radiation vs. time. 8

9 GPS Pressure 1000 Height [m] Time [s] Figure 4: As it is shown on the graph, our CanSat reached altitude 1300 m above the ground and the mission lasted for 130 s. Velocity 150 Velocity [m/s] Time [s] Figure 5: The rocket with CanSats was lifting up at the speed of 150 m/s! 9

10 60 50 Acceleration from accelerometer Acceleration according to pressure sensor 40 Acceleration [m/s^2] Time [s] Figure 6: The maximum acceleration was lower than we expected - only about 6 g. 30 UV smaller range UV bigger range 25 UV radiation [W/m^2] Height [m] Figure 7: It was a quite sunny day and one of UV sensors (with small measurement range) was out of the range all the time. But the second one was working correctly. 10

11 3 CMOS and CCD image sensors as ionising radiation detectors Authors: Michał Gumiela, Rafał Kozik AGH University of Science and Technology in Cracow Supervisor: PhD Michał Krupin ski The Institute of Nuclear Physics, PAN in Cracow A photo of damaged Fukushima Daiichi nuclear power plant [fig. 8] was a motivation to begin the experiments. The whole surface of the photo was covered by strange dots. The dots have been suspected to be traces which occured under the influence of gamma quanta. Figure 8: Bright dots on the picture were suspected to be the signal occured under the influence of gamma quanta. [2] The main aims were: to explore responses of CCD and APS image sensors to different kind of ionising radiation to check whether cheap, commercial image sensors can be used in radiation intensity 11

12 measurement and radiation beams imaging. 3.1 The Aims The aim of the research was to examine a possibility of use/using popular and cheap CMOS (Active Pixel Sensor) and CCD (Charge-Coupled Device) image sensors as detectors of ionizing radiation. The study was conducted for sensors from photo cameras, web cameras and mobile phones. Responses to five types of ionizing radiation (alpha, beta, gamma, X-rays, protons) were investigated. It was shown that both CCD and CMOS arrays are sensitive to all above mentioned types of the ionizing radiation and after calibration procedure they are possible to measure level of radiation. 3.2 How it works? The principle of radiation detection of the image sensors is based on the specific interaction of the radiation particles with the semiconductor, leading to the production of charge carriers. When the particle interacted with a CMOS or CCD array, the dark current measured from the pixels surrounding the place of stroke significantly increases. On the frames gathered from the camera it occurs as bright pixels, which are easy to detect. 3.3 Used detectors Model Creative Live! Cam IM Pro Tytanum Onyx Number of pixels 640 x x 240 Dimensions of image sensor 2, 3 x 1, 73 mm 2 1, 27 x 1, 08 mm 2 Surface of image sensor 3, 98 mm 2 1, 37 mm 2 Dimensions of pixel 3, 6 x 3, 6 µm 4, 0 x 4, 4 µm Sampling frequency 30 Hz 30 Hz Connection port USB USB Price 20 zł 15 zł Table 1: The main parameters of used image sensors [1] 12

13 3.4 Detection of different types of ionising radiation Alpha particles In order to adapt an image sensor from camera as alpha particles detector, camera lens was removed but no other changes were introduced. Traces left by particles were counted and analyzed by specially prepared software. The sensor was tested using 241 Am and 2 39Pu alpha radiation sources. It was noted that the camera-based detector was two times more sensitive in comparison to a commercial Eco-C Geiger-Muller counter. The CCD image sensor endurance for alpha particles was investigated as well. Beta particles The measurements of CCD detector response for beta radiation were carried out in the same way as in the case of alpha radiation. 14 C, 90 Sr and 90 Y sources were used. The results show that image sensors are less sensitive to beta radiation, however it is still possible to detect it with reasonable efficiency. Dosimetry of gamma radiation During the studies it was also found that CMOS arrays can be successfully calibrated as gamma radiation dosimeters. 137 Cs gamma radiation source was utilized to determine the calibration factors in a wide range of dose rate from 3 mgy h up to 830 mgy h. The possibility of using mobile phones with a built-in camera as an alarm against a high level of gamma radiation was tested on the example of the SE XPeria Neo V mobile phone. Written application for Android OS allowed to detect dose rates as low as 9 µgy h. The application is available to download from Google Play store for free Radiation Alarm and allows everyone to have a portable gamma radiation sensor in own pocket. 13

14 Figure 9: Results of calibration of two the same tablets and the smartphone as gamma rays dosimeters. Imaging of X-ray beams Since X-ray is very similar to the gamma radiation but less energetic, CMOS and CCD arrays are more sensitive to X-rays than to gamma rays. In fact, from hundreds of thousands or millions of pixels making up the array, each pixel constitutes an independent radiation sensor. It made the imaging of X-rays beams possible with high spatial resolution. During the studies it has been shown that cheap camera sensors can be used for precision imaging and diagnostic of X-ray beams [fig. 10]. The CMOS sensor together with specially written software allows analysing gathered data, measure dimensions as well as browsing cross sections of the X-ray beams. The system based on image sensor from a photo camera was successfully used both for imaging beams of X-rays with very high spatial resolution as well as for making radiographs of small electronic elements (resistors, capacitors etc.). The resulting spatial resolution was better than 20 µm. 14

15 0 1 mm Pixels mm I/I0 I/I Pixels Figure 10: The example of image of the circle-shaped X-ray beam made using CMOS image sensor. Imaging of proton beams The last part of the studies concerned protons detection. For the purpose of the research the beam of 2 MeV protons was utilized and CMOS array from a web camera was used as detector. It has been shown that the sensor can both count protons and deliver information concerning the place where proton hit the array. The spatial resolution was determined to 5.4 µm. High resolution and sensitivity allows to diagnose the beams of single protons, determine the shape of the beam and investigate the probability of hitting a chosen area by single protons. It could be therefore useful in research with irradiating a biological set-up (for example cancer cells) by single protons. 15

16 3.5 Summary To sum up, cheap CCD and CMOS image sensors could be used both in laboratories and in everyday life. Their main advantages are: low price - starting at a few euros, high spatial resolution and in most cases satisfactory sensitivity. The paper is available to download on camdetector.eu webpage. References [1] Rafał Kozik Michał Gumiela. Studies of the applicability of cmos and ccd sensors for detection, dosimetry and imaging of alpha, beta, gamma, x-ray and proton beam spots. for_ionizing_radiatio.pdf, [2] TEPCO. Accessed: October