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Dear Diana Carolina Herrera Muñoz,

The submission of your abstract has been successfully processed.

Abstract submitted: https://indico.cern.ch/event/192695/call-for- abstracts/my-abstracts.

Status of your abstract: https://indico.cern.ch/event/192695/call- for-abstracts/255/.

See below a detailed summary of your submitted abstract:

Conference: Tipp 2014 - Third International Conference on Technology and Instrumentation in Particle Physics

Submitted by: HERRERA MUÑOZ, Diana Carolina

Submitted on: 24 February 2014 10:30

Title: Study of Columnar Recombination in Xe+trymethilamine Mixtures using a Micromegas-TPC

Abstract content Electron-ion recombination is experimentally studied in Xe+trimethylamine mixtures, motivated by its potential use for directional dark matter searches. A time projection chamber of 2.4 l with a novel configuration formed by two symmetric drift regions with two microbulk-Micromegas readouts is used to measure the recombination of $\alpha$- and $\gamma$-particles, which are emitted in coincidence by an $^{241}$Am source. A gas mixture of 98%Xe+2%TMA is used, varying the pressure from 2 to 10 bar, and the reduced drift field within 10-400 V/cm/bar range. Both $\alpha$- and $\gamma$-particles exhibit recombination as the electric drift field decreases, being stronger for $\alpha$- particles. This is partially explained by columnar recombination due to the dependency observed with the track angle (relative to the direction of electric drift field). The comparison of the data with the theoretical models for recombination will be shown and discussed. These results support a suggestion that has been recently put forward on how to obtain a directional signal in the recoils induced by Dark Matter interactions with xenon-gas. In fact, there are already efforts trying to pursue directionality but with very low masses.

Summary

Primary Authors: Ms. HERRERA MUÑOZ, Diana Carolina (Universidad de Zaragoza (ES)) dcherreramu@gmail.com

Co-authors: GARCIA IRASTORZA, Igor (Universidad de Zaragoza (ES)) igor.irastorza@cern.ch GONZALEZ DIAZ, Diego (Universidad de Zaragoza (ES)) diego.gonzalez.diaz@cern.ch Mr. DAFNI, Theopisti (Universidad de Zaragoza (ES)) theopisti.dafni@cern.ch BASTOS DE OLIVEIRA, Carlos Alberto (Lawrence Berkeley National Lab, CA, USA) cabdoliveira@lbl.gov LONG, Megan (L) mlong@lbl.gov IGUAZ GUTIERREZ, Francisco Jose (Universidad de Zaragoza (ES)) francisco.jose.iguaz.gutierrez@cern.ch RENNER, Joshua (UC Berkeley / Lawrence Berkeley National Lab) jrenner@lbl.gov Dr. GOLDSCHMIDT, Azriel (UC Berkeley /Lawrence Berkely National Lab) agoldschmidt@lbl.gov

Abstract presenters: Ms. HERRERA MUÑOZ, Diana Carolina

Track classification: Sensors: 1c) Gaseous Detectors Sensors: 1e) Novel technologies

Presentation type: Oral

Comments: This work is the continuation of a previous experimental investigation performed with this mixture for double beta decay searches. The main conclusions are in the following contributions 1. D. C. Herrera et al., Micromegas-TPC operation at high pressure in Xenon-trimethylamine mixtures, JINST, 460 - 1742-6596, pp. 1 - 8. 2013. ISSN 1748-0221 Tipo de producción: Artículo 2. S. Cebrián et al., Micromegas-TPC operation at high pressure in xenon-trimethylamine mixtures, JINST, 8, pp. 0 - P01012 [17 pp]. 2013. ISSN 1748-0221