1 / 9

µ M egas used at n_TOF

µ M egas used at n_TOF. µMGAS principles. µMGAS is a two stage ionization chamber (improved version of a ionization with frish - grid) 1 st : ionization&drift (low field) 2 nd : amplification (high field) Converted needed to ionize the gas ( n, a ) 10 B, 6 Li

bevis
Download Presentation

µ M egas used at n_TOF

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. µMegas used at n_TOF

  2. µMGAS principles • µMGAS is a two stage ionization chamber (improved version of a ionization with frish-grid) • 1st : ionization&drift (low field) • 2nd : amplification (high field) • Converted needed to ionize the gas • (n,a) 10B, 6Li • Elastic recoil in the foil or in the gas • (n,f) 235U or any other fissioning nuclide

  3. µMGAS advantages • Thanks to its two stages µMGAS is a very versatile detector. • By playing on the applied voltages can be sensitive from X-ray to fission fragments • Gas mixture can also enhanced or diminish sensitivity to some particles: • Gas easily available at CERN: • Ar + 10%CF4 + 2%iCH4 (fast, and good resolution) • He + 2% iCH4 (slower, not so good resolution but almost insensitive to g-flash)

  4. The micromesh technology • Micromesh is built by chemical treatments applied on coppered kapton • Support removed to increase the transparency

  5. The monitoring µMGAS used in 2010 • 10B4C (~0.7 µm) on a 1 µm coppered kapton(12.5 µm) • 5/25/5 µm (Cu/kapton/Cu) micromesh • ~18.5 mg 235UF4 (70 mm diam.) on 20 µm Al • 5/50/5 (Cu/kapton/Cu) micromesh • Entrance and exit windows: 12.5 µmkapton • Gas (~1 atm): Ar (88%) + CF4 (8%) + iCH4 (2%)

  6. Transmission from monitoring µMGAS(from Raul Sarmento)

  7. The XY-MGAS • Charges are collected through strips used to create an X–Y structure out of electrically connected pads • n_TOF XY µMGAS consists in: • 106x106 strips with a pitch of 550 µm • Strips are read by means of two 96 channels Gassiplex cards The effective center of the detector is not the geometrical one

  8. XY-signals

  9. Ongoing work with µMGAS • Fabrication of a new XY-MGAS since the current one shown some malfunctioning zones this year. • Mounting and electric connection of fission tagging µMGAS has to be improved. • Electronic needs to be improved: • signal is built by combining the energy output of a preamp and a TFA -> signal is too slow and the preamp is not suited for big signals or high count rate.

More Related