A UV LED-based fast-pulsed photoelectron source for time-of-flight studies

New Journal of Physics (Impact Factor: 3.67). 02/2009; DOI: 10.1088/1367-2630/11/6/063018
Source: arXiv

ABSTRACT We report on spectroscopy and time-of-flight measurements using an 18 keV fast-pulsed photoelectron source of adjustable intensity, ranging from single photoelectrons per pulse to 5 photoelectrons per microsecond at pulse repetition rates of up to 10 kHz. Short pulses between 40 ns and 40 microseconds in length were produced by switching light emitting diodes with central output wavelengths of 265 nm and 257 nm, in the deep ultraviolet (or UV-C) regime, at kHz frequencies. Such photoelectron sources can be useful calibration devices for testing the properties of high-resolution electrostatic spectrometers, like the ones used in current neutrino mass searches. Comment: 16 pages, 11 figures

  • [Show abstract] [Hide abstract]
    ABSTRACT: The KArlsruher TRItium Neutrino experiment KATRIN aims to determine the mass of the electron antineutrino with a sensitivity of 0.2 eV/c2 on m(νe) at 90% confidence level by measuring the kinematics of the tritium beta decay with a spectrometer of MAC-E filter-type. To investigate the properties of the spectrometer, electron sources with special properties are needed. A pulsed UV LED photoelectron source with angular selectivity has been developed for this purpose. The principle has been successfully tested during measurements at the spectrometer of the Mainz neutrino mass experiment.
    Progress in Particle and Nuclear Physics 04/2010; 64(2):288-290. DOI:10.1016/j.ppnp.2009.12.031 · 2.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The KATRIN experiment aims at a measurement of the neutrino mass with a 90 % C.L. sensitivity of 0.2 eV/c$^2$ by measuring the endpoint region of the tritium $\beta$ decay spectrum from a windowless gaseous molecular tritium source using an integrating spectrometer of the MAC-E-Filter type. We discuss the idea of using the MAC-E-Filter in a time-of-flight mode (MAC-E-TOF) in which the neutrino mass is determined by a measurement of the electron time-of-flight (TOF) spectrum that depends on the neutrino mass. MAC-E-TOF spectroscopy here is a very sensitive method since the $\beta$-electrons are slowed down to distinguishable velocities by the MAC-E-Filter. Their velocity depends strongly on their surplus energy above the electric retarding potential. Using MAC-E-TOF, a statistical sensitivity gain is expected. Because a small number of retarding-potential settings is sufficient for a complete measurement, in contrast to about 40 different retarding potentials used in the standard MAC-E-Filter mode, there is a gain in measurement time and hence statistical power. The improvement of the statistical uncertainty of the squared neutrino mass has been determined by Monte Carlo simulation to be a factor 5 for an ideal case neglecting background and timing uncertainty. Additionally, two scenarios to determine the time-of-flight of the $\beta$-electrons are discussed, which use the KATRIN detector for creating the stop signal and different methods for obtaining a start signal. These comprise the hypothetical case of an `electron tagger' which detects passing electrons with minimal interference and the more realistic case of `gated filtering', where the electron flux is periodically cut off by pulsing the pre-spectrometer potential.
    New Journal of Physics 08/2013; 15(11). DOI:10.1088/1367-2630/15/11/113020 · 3.67 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this contribution, we review the status and perspectives of direct neutrinomass experiments, which investigate the kinematics of 𝛽-decays of specific isotopes (3H, 187Re, 163Ho) to derive model-independent information on the averaged electron (anti)neutrino mass. After discussing the kinematics of 𝛽-decay and the determination of the neutrino mass, we give a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for 3H, cryobolometers for 187Re). We then describe the Karlsruhe TritiumNeutrino (KATRIN) experiment currently under construction at Karlsruhe Institute of Technology, which will use the MAC-E-Filter principle to push the sensitivity down to a value of 200meV (90% C.L.). To do so, many technological challenges have to be solved related to source intensity and stability, as well as precision energy analysis and low background rate close to the kinematic endpoint of tritium 𝛽-decay at 18.6 keV.We then review new approaches such as the MARE, ECHO, and Project8 experiments, which offer the promise to perform an independent measurement of the neutrino mass in the sub-eV region. Altogether, the novel methods developed in direct neutrino mass experiments will provide vital information on the absolute mass scale of neutrinos.
    Advances in High Energy Physics 10/2012; 2013. DOI:10.1155/2013/293986 · 3.50 Impact Factor


Available from