Bir polarize döteron hedefin polarizasyon miktarının ölçülmesi
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Date
1994
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İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü
Abstract
Avrupa Nükleer Araştırma Merkezi (CERN)’de Spin Muon Collaboration (SMC) deneyinde nükleonların spine bağlı yapı fonksiyonları (gp1 ve gn1) ölçülmektedir. Bunun için enerjisi 200 GeV’ye kadar olan polarize leptonların (µ+), polarize edilmiş nükleonlardan (proton ve nötron için döteron) derin inelastik saçılmasına bakılmaktadır.
Bu spine bağlı yapı fonksiyonlarını hesaplayabilmek için deneyin kalbi sayılan hedefin polarizasyon miktarını iyi bir doğrulukla bilmek gereklidir. Bu nedenle polarizasyonu ölçmek için Nükleer Manyetik Rezonans (NMR) tekniği kullanılmaktadır. Bunun için Radyofrekans (RF), Alçakfrekans (LF) ve sayısal (dijital) bölümlerinden oluşan NMR devresi kullanıldı. Bu devreden elde edilen NMR spektrumlarını kullanarak Isısal Denge (TE) veya Asimetri metotlarıyla hedefin polarizasyonu ölçülebilir.
Deneyin çalışması esnasında diğer adı Alan metodu olan TE metotu kullanılmaktadır. Bu metotda hedefin polarizasyonu ile TE(NMR) spektru- munun altındaki alan arasında bir doğru orantı vardır. Buradaki orantı sabiti ise TE kalibrasyonu yapılarak bulunmaktadır. Diğer bir metot olan asimetri metotunda ise polarizasyon, NMR devresinden elde edilen spektrumun bir fonksiyona fit edilmesi ile spektrumun tepeleri arasındaki oran (R) bulunmaktadır.
Bu iki metotla bulunan polarizasyon değerlerinin birbirlerine çok iyi bir uyum içinde oldukları görülmektedir.
The NA47 experiment at CERN of Spin Muon Collaboration (SMC) is aimed at measuring the deep inelastic scattering of polarised muons from polarised nucleons to provide information on the spin dependent structure function of the proton and the neutron. Recently 100 GeV/c muons have been scattered from a deuterated butanol polarised target to provide information on the spin structure function of the neutron. SMC experiment setup consists of polarised target, which is the heart of the experiment, the spectrometer and polarimeter. The spectrometer has been adapted to the high flux of 4 xlO7 muons per pulse of 2.6 s repeated every 14.4 s. The scattered muon, whose momentum is analysed by the Forward Spectrometer Magnet (FSM), is identified by a set of trigger hodoscopes after having penetrated an iron absorber wall (Fig. 1 a). Besides there is an array of streamer and drift tubes, altogether consisting of 44 planes. Another 8 planes of proportional chambers exist in this region. Additional chambers upstream of the absorber increase the redundancy also in this region. The polarimeter, which is located downstream of the main spectrometer, (Fig. 1 b) determines the beam polarisation by two independent methods. A combination of both methods will result in a beam polarisation measurement of about 5 % overall accuracy. The polarised target which is the heart of the experimental setup consists of the 3He - 4He dilution refrigerator, superconducting solenoid providing a longitudinal magnetic field of 2.5 Tesla, two seperate microwave systems for Dynamic Nuclear Polarisation (DNP) and the Nuclear Magnetic Resonance (NMR) measuring the polarisation of polarised target. During Dynamic Nuclear Polarisation (DNP), the temperature in the target region is about 0.5°K. Under these conditions free electron spins are completely aligned, whereas protons and deuterons are essentially unpolarised. DNP transfers the electron polarisation to the protons or deuterons by means of microwave radiation close to the electron spin resonance line of 70 GHz. The slightly different frequencies needed to generate parallel and antiparallel longitudinal polarisation are provided by two seperate microwave systems. This allows to build up opposite polarisations in the two target sections simultaneously. So the polarised target consists of an upstream and a
The NA47 experiment at CERN of Spin Muon Collaboration (SMC) is aimed at measuring the deep inelastic scattering of polarised muons from polarised nucleons to provide information on the spin dependent structure function of the proton and the neutron. Recently 100 GeV/c muons have been scattered from a deuterated butanol polarised target to provide information on the spin structure function of the neutron. SMC experiment setup consists of polarised target, which is the heart of the experiment, the spectrometer and polarimeter. The spectrometer has been adapted to the high flux of 4 xlO7 muons per pulse of 2.6 s repeated every 14.4 s. The scattered muon, whose momentum is analysed by the Forward Spectrometer Magnet (FSM), is identified by a set of trigger hodoscopes after having penetrated an iron absorber wall (Fig. 1 a). Besides there is an array of streamer and drift tubes, altogether consisting of 44 planes. Another 8 planes of proportional chambers exist in this region. Additional chambers upstream of the absorber increase the redundancy also in this region. The polarimeter, which is located downstream of the main spectrometer, (Fig. 1 b) determines the beam polarisation by two independent methods. A combination of both methods will result in a beam polarisation measurement of about 5 % overall accuracy. The polarised target which is the heart of the experimental setup consists of the 3He - 4He dilution refrigerator, superconducting solenoid providing a longitudinal magnetic field of 2.5 Tesla, two seperate microwave systems for Dynamic Nuclear Polarisation (DNP) and the Nuclear Magnetic Resonance (NMR) measuring the polarisation of polarised target. During Dynamic Nuclear Polarisation (DNP), the temperature in the target region is about 0.5°K. Under these conditions free electron spins are completely aligned, whereas protons and deuterons are essentially unpolarised. DNP transfers the electron polarisation to the protons or deuterons by means of microwave radiation close to the electron spin resonance line of 70 GHz. The slightly different frequencies needed to generate parallel and antiparallel longitudinal polarisation are provided by two seperate microwave systems. This allows to build up opposite polarisations in the two target sections simultaneously. So the polarised target consists of an upstream and a
Description
TENMAK D.N. 10511
Keywords
Forward Spectrometer Magnet (FSM), İleri Spektrometre Mıknatısı (FSM), Dynamic Nuclear Polarisation (DNP), Dinamik Nükleer Polarizasyon (DNP), Nuclear Magnetic Resonance (NMR), Nükleer Manyetik Rezonans (NMR), Nucleons, Nükleonlar, Measurement of polarisation, Polarizasyon ölçümü, Spin muon collaboration, Spin muon işbirliği
Citation
Reyhancan, İ. A. (1994). Bir polarize döteron hedefin polarizasyon miktarının ölçülmesi. (Yayımlanmamış yüksek lisans tezi). İstanbul : İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü.