[Clas12_high_luminosity] Gaseous detector seminar on Wednesday 2nd at 3 pm - IJCLab

[Kondo Gnanvo]

Dear all, 
Please find below the details of upcoming seminar at IJCLab tomorrow at 9 am EST 
Best regards 
Kondo

-----Original Message-----
From: Gabriel Charles <gabriel.charles at ijclab.in2p3.fr> 
Sent: Tuesday, April 1, 2025 4:08 PM
To: Kondo Gnanvo <kagnanvo at jlab.org>
Subject: [EXTERNAL] Fwd: Next seminar on Wednesday 2nd at 3 pm

Hi Kondo,

 Could you forward the invitation to attend the next seminar, please?


Objet: Next seminar on Wednesday 2nd at 9 am (East Coast Time)

Hello everybody,

 Just a kind reminder about our next seminar.

 Link for the presentation: https://urldefense.proofpoint.com/v2/url?u=https-3A__ijclab.zoom.us_j_9524961034-3Fpwd-3DRGZXcnJiRWJWVUdUU25GTk9rWWhoZz09&d=DwIFaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=8RkWGK8Ehr23aQ4XZaeJkKhdeUjRK7rjlS9Ivaen0wM&m=RRZzp4YLmukBXCjly4sKjIW0YrCvch9z7UoLGWQSRGgBjv3JVVGkrGSebi7jAE0I&s=ss3hb66wbc6PzvhvCLFsBnsMgbz3P1A4ow4IsgjHCbI&e=
 Feel free to forward the invitation to anyone that could be interested.
 
 Speaker: Carole Chatel
 Title: Experimental validation of a the Gaseous Proton Recoil Telescope for quasi-absolute neutron flux measurements for fission cross section
 
 You can find the abstract here:
The improvement of neutronics simulations makes their accuracy more sensitive to the precision of the input data, such as neutron-induced cross sections. Among the most important ones, fertile actinides fission cross sections play a key role as they become fissile in a fast neutron flux, above
1 to 2 MeV, which is the peak of neutron population in a thermal, as well as fast, reactor core.

In order to obtain a precise fission cross section, high accuracy neutron flux measurements are essential. The standard technique is a comparison between the nucleus of interest and a reference.
The later can be the 1H(n,n)p cross section, known with an accuracy of 0.2 to 0.5% over the energy range 0-20 MeV, using the proton recoil technique. The neutron flux is then converted through a hydrogenated sample of chosen thickness into a more easily countable proton flux that a proton recoil detector detects. An accurate cross section measurement requires an accurate count of recoil protons.
The use of a recoil proton detector having a perfectly known intrinsic efficiency in all operating regimes and a linear response with respect to the input signal is therefore mandatory.

Above 1 MeV, a silicon junction is fully adequate and commonly used. However, at lower energies, the large number of gamma and electrons generated by the neutron source creates a crippling background noise, making this detector not suitable anymore. The other already-existing detectors not fitting all the requirements, the Gaseous Proton Recoil Telescope (GPRT) is developed for accurate measurement below 1 MeV and down to 200 keV. Its aim is to provide a quasi-absolute neutron flux measurement with an accuracy better than 2%, achievable because insensitive to gamma and electrons noise.

This presentation will thus focus on the description and characterization of this detector, composed of a double ionization chamber and using a segmented Micromegas detection plane. The pressure of the gas in the chamber can be adjusted to protons stopping range – and therefore to neutrons energy. The use of a slow gas enables the access to the third dimension. The possibility to reconstruct tracks and to reject background will hence be presented.

A particular attention has been paid to the optimal operation conditions of the detector, and especially to its intrinsic efficiency. The works carried out successively with an alpha source, a proton micro-beam and a test bench to verify a 100% intrinsic efficiency will be highlighted and the quantification of a dead time of 7.3 ms will be explained.


Have a nice day,
--
Gabriel
IJCLab/IN2P3/CNRS, University Paris-Saclay
+33 1 69 15 64 42
Pictures about detectors:
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.instagram.com_particledetectors_&d=DwIFaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=8RkWGK8Ehr23aQ4XZaeJkKhdeUjRK7rjlS9Ivaen0wM&m=RRZzp4YLmukBXCjly4sKjIW0YrCvch9z7UoLGWQSRGgBjv3JVVGkrGSebi7jAE0I&s=dPH2vv8Pebwi0EK2pfhMDzikgxP4uZyHzb5J5ROo1jI&e=