| Records |
| Author |
Beneke, M.; Hellmann, C.; Ruiz-Femenia, P. |
| Title |
Non-relativistic pair annihilation of nearly mass degenerate neutralinos and charginos III. Computation of the Sommerfeld enhancements |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
05 |
Issue |
5 |
Pages |
115 - 57pp |
| Keywords |
Cosmology of Theories beyond the SM; Supersymmetric Standard Model; Nonperturbative Effects |
| Abstract |
This paper concludes the presentation of the non-relativistic effective field theory formalism designed to calculate the radiative corrections that enhance the pair-annihilation cross sections of slowly moving neutralinos and charginos within the general minimal supersymmetric standard model (MSSM). While papers I and II focused on the computation of the tree-level annihilation rates that feed into the short-distance part, here we describe in detail the method to obtain the Sommerfeld factors that contain the enhanced long-distance corrections. This includes the computation of the potential interactions in the MSSM, which are provided in compact analytic form, and a novel solution of the multi-state Schrodinger equation that is free from the numerical instabilities generated by large mass splittings between the scattering states. Our results allow for a precise computation of the MSSM neutralino dark matter relic abundance and pair-annihilation rates in the present Universe, when Sommerfeld enhancements are important. |
| Address |
[Beneke, M.; Hellmann, C.] Tech Univ Munich, Phys Dept T31, D-85748 Garching, Germany, Email: charlotte.hellmann@tum.de; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Springer |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1029-8479 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000354959300001 |
Approved  |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2235 |
| Permanent link to this record |
| |
|
| |
| Author |
Vincent, A.C.; Fernandez Martinez, E.; Hernandez, P.; Mena, O.; Lattanzi, M. |
| Title |
Revisiting cosmological bounds on sterile neutrinos |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
006 - 23pp |
| Keywords |
particle physics – cosmology connection; cosmological neutrinos; cosmology of theories beyond the SM |
| Abstract |
We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter R-CMB and the sound horizon r(s) from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin(2) theta less than or similar to 0.026(m(s)/eV)(-2). |
| Address |
[Vincent, Aaron C.] Univ Durham, Dept Phys, IPPP, Durham DH1 3LE, England, Email: aaron.vincent@durham.ac.uk; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1475-7516 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000355742500007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2261 |
| Permanent link to this record |
| |
|
| |
| Author |
Pallis, C.; Shafi, Q. |
| Title |
Gravity waves from non-minimal quadratic inflation |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
03 |
Issue |
3 |
Pages |
023 - 31pp |
| Keywords |
inflation; supersymmetry and cosmology; cosmology of theories beyond the SM |
| Abstract |
We discuss non-minimal quadratic inflation in supersymmetric (SUSY) and non-SUSY models which entails a linear coupling of the inflaton to gravity. Imposing a lower bound on the parameter c(R), involved in the coupling between the inflaton and the Ricci scalar curvature, inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity up to the Planck scale. Working in the non-SUSY context we also consider radiative corrections to the inflationary potential due to a possible coupling of the inflaton to bosons or fermions. We find ranges of the parameters, depending mildly on the renormalization scale, with adjustable values of the spectral index n(s), tensor-to-scalar ratio r similar or equal to (2 – 4) . 10(-3), and an inflaton mass close to 3 . 10 (13) GeV. In the SUSY framework we employ two gauge singlet chiral superfields, a logarithmic Kahler potential including all the allowed terms up to fourth order in powers of the various fields, and determine uniquely the superpotential by applying a continuous R and a global U(1) symmetry. When the Kahler manifold exhibits a no-scale-type symmetry, the model predicts n(s) similar or equal to 0.963 and r similar or equal to 0.004. Beyond no-scale SUGRA, n(s) and r depend crucially on the coefficient involved in the fourth order term, which mixes the inflaton with the accompanying non-inflaton field in the Kahler potential, and the prefactor encountered in it. Increasing slightly the latter above (-3), an efficient enhancement of the resulting r can be achieved putting it in the observable range. The inflaton mass in the last case is confined in the range (5 – 9) . 10(13) GeV. |
| Address |
[Pallis, Constantinos] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: cpallis@ific.uv.es; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1475-7516 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000355633800023 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2263 |
| Permanent link to this record |
| |
|
| |
| Author |
de Azcarraga, J.A.; Fedoruk, S.; Izquierdo, J.M.; Lukierski, J. |
| Title |
Two-twistor particle models and free massive higher spin fields |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
010 - 39pp |
| Keywords |
Field Theories in Lower Dimensions; Higher Spin Symmetry; Extended Supersymmetry; Space-Time Symmetries |
| Abstract |
We present D = 3 and D = 4 world-line models for massive particles moving in a new type of enlarged spacetime, with D-1 additional vector coordinates, which after quantization lead to towers of massive higher spin (HS) free fields. Two classically equivalent formulations are presented: one with a hybrid spacetime/bispinor variables and a second described by a free two-twistor dynamics with constraints. After first quantization in the D = 3 and D = 4 cases, the wave functions satisfying a massive version of Vasiliev's free unfolded equations are given as functions on the SL(2, R) and SL(2, C) group manifolds respectively, which describe arbitrary on-shell momenta and spin degrees of freedom. Further we comment on the D = 6 case, and possible supersymmetric extensions are mentioned as well. Finally, the description of interactions and the Ads/crr duality are briefly considered for massive IHS fields. |
| Address |
[de Azcarraga, J. A.] Univ Valencia, Dept Theoret Phys, E-46100 Burjassot, Valencia, Spain, Email: j.a.de.azcarraga@ific.uv.es; |
| Corporate Author |
|
Thesis |
|
| Publisher |
Springer |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1029-8479 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000356852000010 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2293 |
| Permanent link to this record |
| |
|
| |
| Author |
Hueso-Gonzalez, F.; Vijande, J.; Ballester, F.; Perez-Calatayud, J.; Siebert, F.A. |
| Title |
A simple analytical method for heterogeneity corrections in low dose rate prostate brachytherapy |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
| Volume |
60 |
Issue |
14 |
Pages |
5455-5469 |
| Keywords |
brachytherapy; low dose rate; heterogeneities; prostate; calcifications |
| Abstract |
In low energy brachytherapy, the presence of tissue heterogeneities contributes significantly to the discrepancies observed between treatment plan and delivered dose. In this work, we present a simplified analytical dose calculation algorithm for heterogeneous tissue. We compare it with Monte Carlo computations and assess its suitability for integration in clinical treatment planning systems. The algorithm, named as RayStretch, is based on the classic equivalent path length method and TG-43 reference data. Analytical and Monte Carlo dose calculations using Penelope2008 are compared for a benchmark case: a prostate patient with calcifications. The results show a remarkable agreement between simulation and algorithm, the latter having, in addition, a high calculation speed. The proposed analytical model is compatible with clinical real-time treatment planning systems based on TG-43 consensus datasets for improving dose calculation and treatment quality in heterogeneous tissue. Moreover, the algorithm is applicable for any type of heterogeneities. |
| Address |
[Hueso-Gonzalez, Fernando; Vijande, Javier; Ballester, Facundo] Univ Valencia, Dept Atom Mol & Nucl Phys, E-46100 Burjassot, Spain, Email: Javier.Vijande@uv.es |
| Corporate Author |
|
Thesis |
|
| Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0031-9155 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000357620400009 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2296 |
| Permanent link to this record |
| |
|
| |
| Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Identification of beauty and charm quark jets at LHCb |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
10 |
Issue |
|
Pages |
P06013 - 29pp |
| Keywords |
Performance of High Energy Physics Detectors; Analysis and statistical methods |
| Abstract |
Identification of jets originating from beauty and charm quarks is important for measuring Standard Model processes and for searching for new physics. The performance of algorithms developed to select b- and c-quark jets is measured using data recorded by LHCb from proton-proton collisions at root s = 7TeV in 2011 and at root s = 8TeV in 2012. The efficiency for identifying a b (c) jet is about 65%(25%) with a probability for misidentifying a light-parton jet of 0.3% for jets with transverse momentum pT > 20GeV and pseudorapidity 2 : 2 < eta < 4.2. The dependence of the performance on the pT and eta of the jet is also measured. |
| Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil |
| Corporate Author |
|
Thesis |
|
| Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1748-0221 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000358004200029 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2314 |
| Permanent link to this record |
| |
|
| |
| Author |
Ballester, F.; Tedgren, A.C.; Granero, D.; Haworth, A.; Mourtada, F.; Fonseca, G.P.; Zourari, K.; Papagiannis, P.; Rivard, M.J.; Siebert, F.A.; Sloboda, R.S.; Smith, R.L.; Thomson, R.M.; Verhaegen, F.; Vijande, J.; Ma, Y.Z.; Beaulieu, L. |
| Title |
A generic high-dose rate Ir-192 brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism |
Type |
Journal Article |
| Year |
2015 |
Publication |
Medical Physics |
Abbreviated Journal |
Med. Phys. |
| Volume |
42 |
Issue |
6 |
Pages |
3048-3062 |
| Keywords |
Ir-192; HDR brachytherapy; Monte Carlo methods; model-based dose calculation; TG-186 |
| Abstract |
Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) Ir-192 source and a virtual water phantom were designed, which can be imported into a TPS. Methods: A hypothetical, generic HDR Ir-192 source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic Ir-192 source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra (R) Brachy with advanced collapsed-cone engine (ACE) and BrachyVision AcuRos (TM)]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and pENELopE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201)(3) voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR Ir-192 source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by different investigators. MC results were then compared against dose calculated using TG-43 and MBDCA methods. Results: TG-43 and PSS datasets were generated for the generic source, the PSS data for use with the ACE algorithm. The dose-rate constant values obtained from seven MC simulations, performed independently using different codes, were in excellent agreement, yielding an average of 1.1109 +/- 0.0004 cGy/(h U) (k = 1, Type A uncertainty). MC calculated dose-rate distributions for the two plans were also found to be in excellent agreement, with differences within type A uncertainties. Differences between commercial MBDCA and MC results were test, position, and calculation parameter dependent. On average, however, these differences were within 1% for ACUROS and 2% for ACE at clinically relevant distances. Conclusions: A hypothetical, generic HDR Ir-192 source was designed and implemented in two commercially available TPSs employing different MBDCAs. Reference dose distributions for this source were benchmarked and used for the evaluation of MBDCA calculations employing a virtual, cubic water phantom in the form of a CT DICOM image series. The implementation of a generic source of identical design in all TPSs using MBDCAs is an important step toward supporting univocal commissioning procedures and direct comparisons between TPSs. |
| Address |
[Ballester, Facundo] Univ Valencia, Dept Atom Mol & Nucl Phys, E-46100 Burjassot, Spain, Email: Facundo.Ballester@uv.es |
| Corporate Author |
|
Thesis |
|
| Publisher |
Amer Assoc Physicists Medicine Amer Inst Physics |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0094-2405 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000356998300031 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2315 |
| Permanent link to this record |
| |
|
| |
| Author |
Doncel, M.; Cederwall, B.; Martin, S.; Quintana, B.; Gadea, A.; Farnea, E.; Algora, A. |
| Title |
Conceptual design of a high resolution Ge array with tracking and imaging capabilities for the DESPEC (FAIR) experiment |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
10 |
Issue |
|
Pages |
P06010 - 15pp |
| Keywords |
Gamma detectors (scintillators, CZT, HPG, HgI etc); Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc) |
| Abstract |
We present results of Monte Carlo simulations for the conceptual design of the high-resolution DESPEC Germanium Array Spectrometer (DEGAS) proposed for the Facility for Ion and Antiproton Research (FAIR) under construction at Darmstadt, Germany. The project is carried out in three phases, although only results for the two first phases will be addressed in this work. The first phase will consist of a re-arrangement of the EUROBALL cluster detectors previously used in the RISING campaign at GSI. The second phase is based on coupling AGATA-type triple-cluster detectors with EUROBALL cluster detectors in a compact geometry around the active ion implantation target of DESPEC. |
| Address |
[Doncel, M.; Cederwall, B.] Royal Inst Technol, Dept Phys, S-10691 Stockholm, Sweden, Email: doncel@kth.se |
| Corporate Author |
|
Thesis |
|
| Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1748-0221 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000358004200026 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2316 |
| Permanent link to this record |
| |
|
| |
| Author |
Candela-Juan, C.; Vijande, J.; Garcia-Martinez, T.; Niatsetski, Y.; Nauta, G.; Schuurman, J.; Ouhib, Z.; Ballester, F.; Perez-Calatayud, J. |
| Title |
Comparison and uncertainty evaluation of different calibration protocols and ionization chambers for low-energy surface brachytherapy dosimetry |
Type |
Journal Article |
| Year |
2015 |
Publication |
Medical Physics |
Abbreviated Journal |
Med. Phys. |
| Volume |
42 |
Issue |
8 |
Pages |
4954-4964 |
| Keywords |
x-ray beams; electronic brachytherapy; surface applicators; dosimetry; uncertainty |
| Abstract |
Purpose: A surface electronic brachytherapy (EBT) device is in fact an x-ray source collimated with specific applicators. Low-energy (<100 kVp) x-ray beam dosimetry faces several challenges that need to be addressed. A number of calibration protocols have been published for x-ray beam dosimetry. The media in which measurements are performed are the fundamental difference between them. The aim of this study was to evaluate the surface dose rate of a low-energy x-ray source with small field applicators using different calibration standards and different small-volume ionization chambers, comparing the values and uncertainties of each methodology. Methods: The surface dose rate of the EBT unit Esteya (Elekta Brachytherapy, The Netherlands), a 69.5 kVp x-ray source with applicators of 10, 15, 20, 25, and 30 mm diameter, was evaluated using the AAPM TG-61 (based on air kerma) and International Atomic Energy Agency (IAEA) TRS-398 (based on absorbed dose to water) dosimetry protocols for low-energy photon beams. A plane parallel T34013 ionization chamber (PTW Freiburg, Germany) calibrated in terms of both absorbed dose to water and air kerma was used to compare the two dosimetry protocols. Another PTW chamber of the same model was used to evaluate the reproducibility between these chambers. Measurements were also performed with two different Exradin A20 (Standard Imaging, Inc., Middleton, WI) chambers calibrated in terms of air kerma. Results: Differences between surface dose rates measured in air and in water using the T34013 chamber range from 1.6% to 3.3%. No field size dependence has been observed. Differences are below 3.7% when measurements with the A20 and the T34013 chambers calibrated in air are compared. Estimated uncertainty (with coverage factor k = 1) for the T34013 chamber calibrated in water is 2.2%-2.4%, whereas it increases to 2.5% and 2.7% for the A20 and T34013 chambers calibrated in air, respectively. The output factors, measured with the PTW chambers, differ by less than 1.1% for any applicator size when compared to the output factors that were measured with the A20 chamber. Conclusions: Measurements using both dosimetric protocols are consistent, once the overall uncertainties are considered. There is also consistency between measurements performed with both chambers calibrated in air. Both the T34013 and A20 chambers have negligible stem effect. Any x-ray surface brachytherapy system, including Esteya, can be characterized using either one of these calibration protocols and ionization chambers. Having less correction factors, lower uncertainty, and based on measurements, performed in closer to clinical conditions, the TRS-398 protocol seems to be the preferred option. |
| Address |
[Candela-Juan, C.; Perez-Calatayud, J.] La Fe Univ, Dept Radiat Oncol, Valencia 46026, Spain, Email: ccanjuan@gmail.com |
| Corporate Author |
|
Thesis |
|
| Publisher |
Amer Assoc Physicists Medicine Amer Inst Physics |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0094-2405 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000358933000051 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2323 |
| Permanent link to this record |
| |
|
| |
| Author |
Solevi, P.; Magrin, G.; Moro, D.; Mayer, R. |
| Title |
Monte Carlo study of microdosimetric diamond detectors |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
| Volume |
60 |
Issue |
18 |
Pages |
7069-7083 |
| Keywords |
ion-beam therapy; microdosimetry; diamonds; GATE |
| Abstract |
Ion-beam therapy provides a high dose conformity and increased radiobiological effectiveness with respect to conventional radiation-therapy. Strict constraints on the maximum uncertainty on the biological weighted dose and consequently on the biological weighting factor require the determination of the radiation quality, defined as the types and energy spectra of the radiation at a specific point. However the experimental determination of radiation quality, in particular for an internal target, is not simple and the features of ion interactions and treatment delivery require dedicated and optimized detectors. Recently chemical vapor deposition (CVD) diamond detectors have been suggested as ion-beam therapy microdosimeters. Diamond detectors can be manufactured with small cross sections and thin shapes, ideal to cope with the high fluence rate. However the sensitive volume of solid state detectors significantly deviates from conventional microdosimeters, with a diameter that can be up to 1000 times the height. This difference requires a redefinition of the concept of sensitive thickness and a deep study of the secondary to primary radiation, of the wall effects and of the impact of the orientation of the detector with respect to the radiation field. The present work intends to study through Monte Carlo simulations the impact of the detector geometry on the determination of radiation quality quantities, in particular on the relative contribution of primary and secondary radiation. The dependence of microdosimetric quantities such as the unrestricted linear energy L and the lineal energy y are investigated for different detector cross sections, by varying the particle type (carbon ions and protons) and its energy. |
| Address |
[Solevi, Paola; Magrin, Giulio; Mayer, Ramona] EBG MedAustron, A-2700 Wiener Neustadt, Austria, Email: paola.solevi@ovgu.de |
| Corporate Author |
|
Thesis |
|
| Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0031-9155 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000361124000004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2379 |
| Permanent link to this record |
