Artículos de revistas
Espectrógrafo magnético para el estudio de reacciones nucleares
Autor
MAZARI , MARCOS
ALBA , FERNANDO
CASTRO , IGNACIO
VÁZQUEZ R., MARIO
Institución
Resumen
A BROAD-RANGE MAGNETIC ESPECTROGRAH, SIMILAR TO THE ONE BUILT BY DE HIGH VOTAGE LABORATORY GROUP OF DE MASSACHUSETTS INSTITUTE OF TECHNOLOGY, HAS BEEN DESIGNED AND BUILT TO BE USED FOR NUCLEAR REACTION STUDIES OF THE LIGHT NUCLEI WITH THE 2 MEV, VAN DE GRAFF MACHINE OF THE NATIONAL UNIVERSITY OF MEXICO. SOME USEFUL CHANGES WERE MADE SUCH AS A NEW DESIGN OF DE VACUUM CHAMBER AND OF THE POWER SUPPLY FOR THE STABILIZATION SYSTEM FOR THE MAGNET. IN THE LAST RUMS THE VACUUM IN THE SYSTEM AS A WHOLE HAS BEEN OF THE ORDER OF 2 X 10_ MM HG. THE ELECTRONIC STABILIZATION SYSTEM AND THE NUCLEAR MAGNETIC FLUXMETER WERE PUT INTO OPERATION WITH STABILITIES OF THE ORDER OF (1/8000). THE PHOTOGRAPHIC CAMERA WAS FOCUSED AND AN ACCURATE CALIBRATION WAS CARRIED ON USING MONOENERGETIC A PARTICLES FROM A PO_ STANDARD SOURCE. OPTIC CHARACTERISTICS AND LIMITATIONS OF DE SPECTROGRAH ARE DISCUSSED IN DEATAIL, AS WELL AS THE EQUATIONS INCLUDING RELATIVISTIC CORRECTIONS TO BE USED IN THE CALCULATION OF THE NUCLEAR REACTIONS WHERE PARTICLES ARE INVOLVED. THE VAN DE GRAFF MACHINE WAS IMPROVED BY MEANS OF A STRONG FOCUSING ELECTROSTATIC LENS PLACED BETWEEN THE DEFLECTING MAGNET AND THE TARGET CHAMBER, IN ORDER TO AVOID ELASTIC SCATTERING THAT PRODUCES A HIGH BACKGROUND IN THE SPECTRA WHEN SLITS OR DIAPHRAGMS ARE USED. AS EXAMPLES OF THE ACCURACY IN THE STUDIES TAHT CAN BE CARRIED OUT WITH THE NEW INSTRUMENT, A O_ (D,P) O_ REACTION WAS STUDIED IN ORDER TO DETERMINE WHETHER THE FIRST EXCITED STATE OF O_ WAS A DOUBLET OR A SINGLET. THE OXYGEN REACTION AND ELASTIC SCATTERING ON C_ AND AU _ WERE USED TO CALIBRATE THE RADIUS OF CURVATURE OF THE DEFLECTING MAGNET. DUE TO THE CROSS SECTION STUDIES THAT THE LABORATORY IS CARRYING ON USING FAST NEUTRONS AND TO THE GENERAL INTEREST IN KNOWING THE ACCURATE Q VALUE OF THE REACTION T(D, A)N, EXPOSURES AT 90_, 80_ AND 60_ WITH RESPECT THE DIRECTION OF A BEAM BITTING A TRITSUM TARGET, WERE DONE BOMBERDING IT WITH 0.63 MEV DEUTERONS. THE MEAN Q VALUE OBTAINED INCLUDING RELATIVISTIC CORRECTIONS IS 17.580 + 0.025 MEV. THE OUTSTANDING CHARACTERISTICS OF THIS SPECTROGRAH ARE THE HIGH RESOLUTION ENERGY RANGE (2.74) COVERED SIMULTANEOUSLY IN AN EXPOSURE AND THE POSSIBILITI OF ROTATING THE SPECTROGRAH FROM 0_ TO 130_ WITH RESPECT TO THE BEAM DIRECTION. A BROAD-RANGE MAGNETIC ESPECTROGRAH, SIMILAR TO THE ONE BUILT BY DE HIGH VOTAGE LABORATORY GROUP OF DE MASSACHUSETTS INSTITUTE OF TECHNOLOGY, HAS BEEN DESIGNED AND BUILT TO BE USED FOR NUCLEAR REACTION STUDIES OF THE LIGHT NUCLEI WITH THE 2 MEV, VAN DE GRAFF MACHINE OF THE NATIONAL UNIVERSITY OF MEXICO. SOME USEFUL CHANGES WERE MADE SUCH AS A NEW DESIGN OF DE VACUUM CHAMBER AND OF THE POWER SUPPLY FOR THE STABILIZATION SYSTEM FOR THE MAGNET. IN THE LAST RUMS THE VACUUM IN THE SYSTEM AS A WHOLE HAS BEEN OF THE ORDER OF 2 X 10_ MM HG. THE ELECTRONIC STABILIZATION SYSTEM AND THE NUCLEAR MAGNETIC FLUXMETER WERE PUT INTO OPERATION WITH STABILITIES OF THE ORDER OF (1/8000). THE PHOTOGRAPHIC CAMERA WAS FOCUSED AND AN ACCURATE CALIBRATION WAS CARRIED ON USING MONOENERGETIC A PARTICLES FROM A PO_ STANDARD SOURCE. OPTIC CHARACTERISTICS AND LIMITATIONS OF DE SPECTROGRAH ARE DISCUSSED IN DEATAIL, AS WELL AS THE EQUATIONS INCLUDING RELATIVISTIC CORRECTIONS TO BE USED IN THE CALCULATION OF THE NUCLEAR REACTIONS WHERE PARTICLES ARE INVOLVED. THE VAN DE GRAFF MACHINE WAS IMPROVED BY MEANS OF A STRONG FOCUSING ELECTROSTATIC LENS PLACED BETWEEN THE DEFLECTING MAGNET AND THE TARGET CHAMBER, IN ORDER TO AVOID ELASTIC SCATTERING THAT PRODUCES A HIGH BACKGROUND IN THE SPECTRA WHEN SLITS OR DIAPHRAGMS ARE USED. AS EXAMPLES OF THE ACCURACY IN THE STUDIES TAHT CAN BE CARRIED OUT WITH THE NEW INSTRUMENT, A O_ (D,P) O_ REACTION WAS STUDIED IN ORDER TO DETERMINE WHETHER THE FIRST EXCITED STATE OF O_ WAS A DOUBLET OR A SINGLET. THE OXYGEN REACTION AND ELASTIC SCATTERING ON C_ AND AU _ WERE USED TO CALIBRATE THE RADIUS OF CURVATURE OF THE DEFLECTING MAGNET. DUE TO THE CROSS SECTION STUDIES THAT THE LABORATORY IS CARRYING ON USING FAST NEUTRONS AND TO THE GENERAL INTEREST IN KNOWING THE ACCURATE Q VALUE OF THE REACTION T(D, A)N, EXPOSURES AT 90_, 80_ AND 60_ WITH RESPECT THE DIRECTION OF A BEAM BITTING A TRITSUM TARGET, WERE DONE BOMBERDING IT WITH 0.63 MEV DEUTERONS. THE MEAN Q VALUE OBTAINED INCLUDING RELATIVISTIC CORRECTIONS IS 17.580 0.025 MEV. THE OUTSTANDING CHARACTERISTICS OF THIS SPECTROGRAH ARE THE HIGH RESOLUTION ENERGY RANGE (2.74) COVERED SIMULTANEOUSLY IN AN EXPOSURE AND THE POSSIBILITI OF ROTATING THE SPECTROGRAH FROM 0_ TO 130_ WITH RESPECT TO THE BEAM DIRECTION.