1. UNIVERSIDAD NACIONAL DE COLOMBIA CRYOMAG Group Hector Castro Physics Department Medical Physics Group Maria C. Plazas Physics Department

2. PARTICLE DETECTORS

3. PARTICLE DETECTORS FOR HIGH ENERGY PHYSICS AND MEDICINE

4. GAZ DETECTORS - RESISTIVE PLATE CHAMBERS (RPC’s) Dr. Archana Sharma, CERN-CMS Dr. George Mikenberg, Weisman Inst.- ATLAS - PIXEL DETECTOR Dr. Crispin Williams, LAD-ALICE ACTUAL STATUS STARTING CONSTRUCTION OF A SMALL RPC PROTOTYPE PROPOSAL SUBMITTED TO COLCIENCIAS Micromegas GEM THGEM MHSP Ingrid

6. NO WIRES

7. SUPERCONDUCTING PARTICLE DETECTORS - TRANSITION EDGE - JOSEPHSON JUNCTION ARRAYS - SQUID’s ARRAY - GRANULAR MATRIX Fast, Robust, Precise, Rad. Resistant STATUS: PROPOSAL SUBMITTED TO COLCIENCIAS

8. IMAGES RADIOGRAPHY: Plates, Solid State, Multiwire PORTAL IMAGES: X Rays COMPUTED TOMOGRAPHY (CT) X-Rays ANGIOGRAPHY: X-RAYS, Synchrotron Rad. MEDICAL APPLICATIONS

9. CLINICAL DOSIMETRY RADIOTHERAPHY & RADIOPROTECTION IRRADIATION PLANNING QUALITY CONTROL SAFETY ANALYSIS NEW

10. IONIZATION CHAMBER - Analog signal - Point to point measurement - Off-line measurement (before or after treatment) - Used to ensure dose from a therapy unit or radiopharmaceutical is what is intended. - Readout by electrometers or nanoamperimeters CLASICAL DOSIMETER

11. CONSTRUCTION OF A PIXEL GAS-DETECTOR FOR MEDICAL DOSIMETRY 2. EXPERIMENTAL SETUP 1. High voltage source 2. Pixel Gas-Detector 3. Gas flow control 4. Istrumentation: preamplifier (Canberra mod. ), Spectroscopy Amplifier (Canberra mod.), ADC unit (Canberra mod. ), PC 1.CLINICAL SIGNIFICANCE - Distribution of absorbed dose by patients is the main control parameter to ensure radiation protection. - Semiconductor detectors, are used today but are expensive. - Particle detectors can be used as dosimeters in radiation therapy. - Gas detectors are excellent choice for dosimetry: cheap, technology at hand, online monitoring. Fig. 4. Photo of Pixel Gas Chamber Fig. 3. Experimental setup 3. PAST PRESENT AND FUTURE This type of detector has been pioneered by C. Williams at CERN, who demonstrated good performance of a similar device [1,2]. We are starting measurements with this prototype in order to optimize it for measurements of X rays and electrons. Clinical tests and dose calibration will be made using radiation sources typical of radiology and radiotherapy treatments. REFERENCES [1] D. Mattern, C. Williams and A. Zichichi, CERN/PPE 90-147, 2 Oct. 1990 [2] Latest Results on the Development of The Gaseous Pixel Chamber D. Antreasyan, H. Castro et al. Proceedings of the 12th Workshop of the INFN ELOISATRON Project, Erice, Italy, 15-20 September 1990, Plenum Press, New York- London, 1991, 153 1 2 3 4 5 Fig. 5 Electric field map of pixel detector with ground plate on top. Fig. 6. Cross section of the pixel detector layer. WORKSHOP ON SCIENCE AND TECHNOLOGY AT CERN, Bogota 20-22 October 2010 E.E.Rozo.A 1,3, H. Castro 1, F. Cristancho 2 CRYOMAG 1, Nuclear Physics (GFNUN) 2, Medical Physics 3 group Universidad Nacional de Colombia, Sede Bogotá Radiotherapy, Nuclear Medicine and Radiology procedures require precise measurements of dose distributions over irradiated areas in order to ensure quality treatments and radiation protection to patients. In this work we address this need by proposing the development of an economical and reliable pixel gas-detector. At this stage of the project we present construction details and instrumentation of the prototype built, which is now being submitted to preliminary tests in order to optimize its operation conditions like voltage, gas mixture and pixel’s size. This work constitutes a first attempt in the development of this technology in our country.

12. NEW DETECTORS FROM HEP TO MEDICINE CERN PROJECTS WE ARE INTERESTED IN - RD51 - CERIMED - ENLIGHT - MEDIPIX

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