360 research outputs found
Energy Resolution from a Silicon Detector’s Interstrip Regions
No full textIn this work, we present a novel approach for improving the energy resolution from particles impinging on the interstrip regions of silicon strip detectors. We employed three double-sided strip detectors from the GRIT array and a triple (Formula presented.) -source under laboratory conditions. The results showed that the interstrip resolution depends not only on the impinging side but also on whether it is a P- or an N-interstrip. We obtained the interstrip energy resolution down to 0.4%, and, depending on the scenario, the resolution was enhanced by a factor of 2. We believe that this new rotation method allows for the possibility of applying particle identification methods on interstrip events, which in most cases are dismissed during data recording
Test Bench for Highly Segmented GRIT Double-Sided Silicon Strip Detectors: A Detector Quality Control Protocol
No full textThis work deals with the characteristics of highly segmented double-sided silicon detectors. These are fundamental parts in many new state-of-the-art particle detection systems, and therefore they must perform optimally. We propose a test bench that can handle 256 electronic channels with off-the-shelf equipment, as well as a detector quality control protocol to ensure that the detectors meet the requirements. Detectors with a large number of strips bring new technological challenges and issues that need to be carefully monitored and understood. One of the standard 500 (Formula presented.) m thick detectors of the GRIT array was investigated, undergoing studies that revealed its IV curve, charge collection efficiency, and energy resolution. From the data obtained, we calculated, among other things, the depletion voltage (110 V), the resistivity of the bulk material (9 k (Formula presented.) cm), and the electronic noise contribution (8 keV). We present, for the first time, a methodology called “the energy triangle’’ to visualize the effect of charge sharing between two adjacent strips and to study the hit distribution with the interstrip-to-strip hit ratio (ISR)
Lifetime measurements in
No full textOne of the most studied case to explore the evolution of shell closures far from stability is the doubly-magic and self-conjugated 100Sn nucleus. Information on its doubly-magic nature can be extracted fromthe systematic study of the tin isotopic chain. In this context, the lifetimes of the neutron deficient 105Sn have been investigated with the coincidence Recoil Distance Doppler Shift (RDDS) technique throughthe reaction 50Cr(58Ni,2pn)105Sn. Preliminary results concerning the lifetimesof 105In excited states are in good agreement with the adopted lifetimes, demonstrating the feasibility to extract lifetimes with this experimental technique
Nuclear structure of the semi-magic tin isotopes close to 100Sn: lifetime measurements of low-lying states in 106Sn and 108Sn
No full textNegli ultimi anni la struttura dei nuclei con pochi nucleoni oltre la doppia chiusura di shell Z=N=50 è stato argomento di discussione sia dal punto teorico che sperimentale. Infatti molti studi sono stati fatti in questa regione per esaminare l'evoluzione dell'interazione nucleone-nucleone in prossimità del nucleo doppio magico 100Sn.
Lungo la catena isotopica dello stagno, l'energia d'eccitazione degli primi stati 2+ e 4+ è ben nota e l'andamento è pressoché costante. Per quanto riguarda la probabilità di transizione ridotta, invece, per gli isotopi dello stagno ricchi di neutroni tale valore sembra seguire il tipico andamento parabolico con il massimo a metà della shell; tuttavia, per i nuclei poveri di neutroni le informazioni su B(E2; 2+→0+) sono affetti da grandi incertezze sperimentali. In aggiunta, per i nuclei di questa regione la mancanza di informazioni relative a B(E2; 4+→2+) rende difficile ottenere una robusta interpretazione teorica.
Infatti, negli ultimi decenni diversi calcoli teorici sono stati fatti ma finora nessuna di queste predizioni è in grado di riprodurre in maniera consistente l'andamento dei risultati sperimentali lungo tutta la catena isotopica.
L'esperimento discusso in questa tesi era finalizzato alla misura della vita media degli stati 2+ e 4+ per i nuclei 106,108Sn con il metodo Recoil-Distance Doppler-Shift (RDDS), per poi derivarne la probabiltà di transizione ridotta. I nuclei di interesse sono stati popolati per mezzo di una reazione di trasferimento di multi-nucleoni: un fascio di 106Cd, fornito dal ciclotrone dei laboratori di GANIL (Francia) all'energia di 770 MeV, ha inciso su un bersaglio di 92Mo. Dopo tale target è stato posto un foglio di 24Mg con lo scopo di rallentare i prodotti della reazione.
Questa misura è complementare ai precedenti esperimenti di eccitazione coulombiana e rappresenta la prima vera misura diretta di vita media per gli isotopi dello stagno poveri di neutroni.
La completa identificazione dei prodotti di reazione è stata ottenuta grazie all'uso dello spettrometro magnetico VAMOS++, mentre la rivelazione dei raggi gamma è avvenuta per mezzo dello spettrometro AGATA. Grazie alla combinazione dello spettrometro magnetico con il particolare meccanismo di reazione, è stato possibile ricostruire il Q-valore della reazione: tale informazione è cruciale per il successo della misura in quanto permette di controllare il popolamento diretto degli stati eccitati.
Concludendo, è stato possibile misurare la vita media degli stati 2+ e 4+ per 106,108Sn. Con lo scopo di ridurre il più possibile l'errore della misura, per il nucleo 108Sn diversi test sono stati fatti sia con il Decay-Curve Method (DCM) che con il Differential Decay-Curve Method (DDCM).
Le probabilità di transizione ridotte B(E2), ottenute a partire dalle nuove vite medie, sono state confrontate con calcoli di Large-Scale Shell-Model (LSSM). Da questo confronto è risultato che tali proprietà nucleari sono molto sensibili alla forma della funzione d'onda: in particolare il nuovo valore B(E2; 4+→2+) del 108Sn mostra l'estrema importanza di includere termini di grande seniorità nella funzione d'onda per poter riprodurre le probabilità di transizione ridotta in questa regione.
Questo risultato mette in dubbio la validità delle precedenti predizioni teoriche, le quali limitavano i valori della seniorità nel riprodurre l'andamento dei valori sperimentali di B(E2)
SLICES : Spes Low-energy Internal Conversion Electron Spectrometer
No full textThe Spes Low-energy Internal Conversion Electron Spectrometer (SLICES) is a new electron spectrometer designed to perform off-beam measurements at the beta decay station of the SPES facility at the Legnaro National Laboratories (LNL). SLICES consists of a large area Si(Li) detector cooled at -150 degrees C and a magnetic transport system. Four permanent N52 magnets, located around a central photon shield focus the electrons on the detector. In this paper, a detailed description of the SLICES components is presented. The strength of the measured magnetic field has been compared with calculations. The efficiency of the apparatus has been simulated and compared with the experimental data obtained using a radioactive Bi-207 source. The commissioning of the spectrometer at the CN accelerator at LNL is also presented
Lifetime measurements using a plunger device and the EUCLIDES Si array at the GALILEO gamma-ray spectrometer
No full textThe GALILEO gamma-ray spectrometer, installed at the Laboratori Nazionali di Legnaro (LNL), benefits from intense stable beams provided by the Tandem-ALPI-PIAVE accelerator complex and from radioactive beams to be delivered in the near future by the SPES facility. the spectrometer is complemented with a variety of ancillary devices to allow for nuclear structure and reaction studies. the 4 pi Si-ball array EUCLIDES coupled to the GALILEO gamma-ray spectrometer represents one of the commonly used setup for experiments aiming at spectroscopic studies. High-efficiency detection of light-charged particles in a fusion-evaporation reaction guarantees good discrimination of different reaction channels and provides essential information for the kinematic reconstruction. in this paper we discuss a configuration of the EUCLIDES array developed for the lifetime measurements of nuclear excited states populated in a fusion-evaporation reaction. in such a configuration a part of the EUCLIDES detectors is disassembled allowing for the installation of a plunger device in the reaction chamber. the reduced configuration of EUCLIDES provides high detection efficiency necessary for reliable light charged-particle discrimination. We report on the commissioning experiment focused on the Ni-58(Ni-58,3p)I-113 reaction. the lifetimes of 11/2(-) and 15/2(-) states were measured by applying the Recoil Distance Doppler Shift method to be equal to 206(20) ps and 7.9(12) ps correspondingly and were in good agreement with the values cited in the literature. Thus, the combination of the GALILEO and EUCLIDES arrays, and the plunger device has resulted in a powerful experimental setup to determine lifetimes of excited states in neutron-deficient nuclei in the picosecond range.National Science Centre, Poland (NCN)National Science Center, PolandNational Science Centre, Poland [2017/25/B/ST2/01569]; CARIPARO foundationFondazione CariparoThe authors would like to thank the technical staff of the LNL-INFN facility for their assistance in providing excellent operation of the XTU-Tandem accelerator. the authors wish to acknowledge the support of local engineers P. Cocconi and R. Isocrate. the work of G. Jaworski was supported by the National Science Centre, Poland (NCN) (grant no. 2017/25/B/ST2/01569). A. Goasduff acknowledges the support of the CARIPARO foundation under the Starting Grant 2017
A high resolution gamma-ray array for the pandora plasma trap [A high resolution γ-ray array for the pandora plasma trap]
No full textThe measurement of beta-decay rates in plasma, simulating stellar-like conditions, is of high interest for the investigation of radionuclides involved in nuclear astrophysics processes. In the new PANDORA plasma trap, to be built at the INFN-Laboratori Nazionali del Sud of Catania (Italy), the beta-decay rates will be estimated by detecting the gamma-rays emitted by the daughter nuclei trapped in the confined plasma. The present work describes the high efficiency High Purity Germanium (HPGe) detector array that will be placed around the magnetic trap for this purpose, as well as the front-end electronics and acquisition system suitable for the array operation in presence of a high counting rate background originating from Bremsstrahlung radiation
Simulation of the AGATA spectrometer and coupling with ancillary detectors
No full textThe design study of the AGATA array began with the development of the AGATA simulation code using GEANT4. The latter played a key part in the final design of the array and provided a cost effective solution for the early development of the tracking algorithm. The code has since been maintained and developed by the collaboration to provide more realistic simulations, with reaction chambers, ancillary detectors and surrounding mechanical structures completing the entire setup
Validation and Characterization of the GALTRACE Silicon Detector Array Demonstrator
No full textThe preliminary results of the GALTRACE (GALILEO TRacking Array for Charged Ejectiles) demonstrator are reported. GALTRACE is an array of Silicon PAD detectors for particle spectroscopy and discrimination to be employed in low-energy nuclear physics experiments with stable and radioactive beams at the Legnaro National Laboratories (LNL, Italy). The readout is perfomed with multi-channel, VLSI preamplifiers realized in AMS 350 nm technology, directly wire-bonded on the PCB. These preamplifiers have a resolution of 125 electrons rms and a risetime of 10 ns with a 4 pF capacitance referred to the input. The preamplifiers have a spectroscopic dynamic energy range of 40 MeV. This value is boosted by more than one order of magnitude by an innovative fast-reset device that allows for 40700 MeV spectroscopy with a resolution of less than 0.3% FWHM. After preamplifier test-bench characterization, a full validation of a TRACE demonstrator including detector, front-end electronics, single-ended to differential converters and digitalization system has been performed. The resolution of the 60 active channels, evaluated at the 5486 keV Am-241 alpha peak, is 35 +/- 5 ke
NEDA-NEutron Detector Array
No full textMillan, Vicente Gonzalez/0000-0001-6014-2586; Huyuk, Tayfun/0000-0003-0597-9767; GOASDUFF, Alain/0000-0003-3453-3297; carturan, sara maria/0000-0002-6702-2867; Sison, Andres Illana/0000-0003-0274-3388; SAYGI, BAHADIR/0000-0001-5406-506X; Jaworski, Grzegorz/0000-0003-2241-0329; Aliaga, Ramon J./0000-0002-2513-7711; Vidal, Rosa Maria Perez/0000-0002-4075-4152; Di Nitto, Antonio/0000-0002-9319-366X; Lazarus, Ian/0000-0003-1235-4984; Hadynska Klek, Katarzyna/0000-0003-1244-9561; Sanchis Peris, Enrique/0000-0002-9689-9131; Moszynski, Marek/0000-0002-1267-2838; Soderstrom, Par-Anders/0000-0002-9504-2814The NEutron Detector Array, NEDA, will form the next generation neutron detection system that has been designed to be operated in conjunction with gamma-ray arrays, such as the tracking-array AGATA, to aid nuclear spectroscopy studies. NEDA has been designed to be a versatile device, with high-detection efficiency, excellent neutron-gamma discrimination, and high rate capabilities. It will be employed in physics campaigns in order to maximise the scientific output, making use of the different stable and radioactive ion beams available in Europe. the first implementation of the neutron detector array NEDA with AGATA 1 pi was realised at GANIL. This manuscript reviews the various aspects of NEDA.Swedish Research Council, SwedenSwedish Research Council [VR 2014-6644]; Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [117F114, 114F473]; Polish National Science Centre, Poland [2017/25/B/ST2/01569, 2016/22/M/ST2/00269 COPIN-IN2P3]; COPIGAL projects, Poland; UK STFCScience & Technology Facilities Council (STFC) [ST/J000124/1, ST/L005727/1, STL005735/1, ST/P003885/1]; Generalitat ValencianaGeneralitat Valenciana [PROMETEO II/2014/019, FPA2017-84756-C4]; MICIU, Spain [PROMETEO II/2014/019, FPA2017-84756-C4]; Severo Ochoa, Spain [SEV-2014-0398]; E.C. FEDER, Spain fundsThis study is supported by the Swedish Research Council, Sweden (contract number VR 2014-6644), the Scientific and Technological Research Council of Turkey (TUBITAK Project No: 117F114 and 114F473), the Polish National Science Centre, Poland, grants nos. 2017/25/B/ST2/01569 and 2016/22/M/ST2/00269 COPIN-IN2P3 and COPIGAL projects, Poland, the UK STFC under grant nos. (ST/J000124/1, ST/L005727/1, STL005735/1, ST/P003885/1), the Generalitat Valenciana and MICIU, Spain, grants PROMETEO II/2014/019, FPA2017-84756-C4, Severo Ochoa, Spain SEV-2014-0398 and by the E.C. FEDER, Spain funds
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