Temperature diagnostics of ECR plasma by measurement of electron bremsstrahlung

Abstract

The x-ray bremsstrahlung spectrum emitted by the electron population in a 14.5 GHz ECR plasma source has been measured using a NaI(Tl) detector, and hence the electron temperature of the higher energy electron population in the plasma has been determined. The x-ray spectra for Ne and Ar gases have been systematically studied as a function of inlet gas pressure from 7 × 10(-7) mbar to 7 × 10(-5) mbar and for input microwave power ∼1 W to ∼300 W. At the highest input power and optimum pressure conditions, the end point bremsstrahlung energies are seen to reach ∼700 keV. The estimated electron temperatures (T(e)) were found to be in the range 20 keV-80 keV. The T(e) is found to be peaking at a pressure of 1 × 10(-5) mbar for both gases. The T(e) is seen to increase with increasing input power in the intermediate power region, i.e., between 100 and 200 W, but shows different behaviour for different gases in the low and high power regions. Both gases show very weak dependence of electron temperature on inlet gas pressure, but the trends in each gas are different.

Electron emission from bromouracil and uracil induced by protons and radiosensitization

“…The experiments were performed in a crossed beam setup where the projectile beam collided with the vapour of uracil or bromouracil. The protons of energy 200 keV were generated from the 14.5 GHz 200 W electron cyclotron resonance (ECR) ion accelerator at TIFR, Mumbai [35][36][37]. The ECR ion accelerators are well known for producing the low velocity, highly charged ions.…”

A recoil ion momentum spectrometer for molecular and atomic fragmentation studies

“…This is a 14.5 GHz-600 W machine 32 with a maximum extraction voltage of 30 kV and mounted on a deck which can be raised up to 400 kV. 33,34 For the present experiment, we have used 120 kV/q proton and O 4+ beams (where q is the charge state of the projectile). The beam is focused on the target by using two sets of electrostatic quadruple lenses and a pair of X-Y deflectors.…”

Characterization of an electrically cooled BEGe detector till Eγ∼7 MeV

“…The present experiment was performed at TIFR, Mumbai, using ECR (Electron Cyclotron Resonance) ion-source based low energy ion accelerator [10,11,12]. An implanted 14 N target previously characterized [13] was bombarded by proton beam at lab energy E lab p = 278 keV.…”