Sadiq Proposal Defense - Revision history

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2012-08-21T23:38:21Z

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2012-08-21T23:14:47Z

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2012-08-21T23:05:44Z

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2012-08-21T16:52:30Z

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2012-08-20T21:17:52Z

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Setisadi at 19:59, 16 August 2012

2012-08-16T19:59:23Z

Setisadi at 10:23, 17 June 2012

2012-06-17T10:23:22Z

Setisadi at 10:23, 17 June 2012

2012-06-17T10:23:05Z

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2012-06-17T10:22:42Z

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Setisadi at 10:21, 17 June 2012

2012-06-17T10:21:04Z

@@ Line 172: / Line 172: @@
         electron beam peak current $I_{\textnormal{peak}}$ &  mA      &  80     \\
          \midrule
-         macro-pulse repetition rate                   &   Hz       &  1000  \\
+         macro-pulse repetition rate                   &   Hz       &  300  \\
          \midrule
          macro-pulse pulse length (FWHM)          &   ns       &  250    \\

@@ Line 159: / Line 159: @@
-I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 300~Hz. The HRRL beamline had recently been reconfigured to generate and collect positrons, see Fig.~\ref{fig:HRRL-e+-line} and Table~\ref{tab:hrrl}.
+I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 300~Hz. The HRRL beamline has recently been reconfigured to generate and collect positrons, see Fig.~\ref{fig:HRRL-e+-line} and Table~\ref{tab:hrrl}.
 \begin{table}[hbt]
@@ Line 241: / Line 241: @@
 An Optical Transition Radiation (OTR) based viewer was installed to allow measurements at the high electron currents available from the HRRL. The visible light from the OTR based viewer is produced when a relativistic electron beam crosses the boundary of two mediums with different dielectric constants.  Visible radiation is emitted at an angle of 90${^\circ}$ with respect to the incident beam direction~\cite{OTR} when the electron beam intersects the OTR target at a 45${^\circ}$ angle. These emitted photons are observed using a digital camera and can be used to measure the shape and intensity of the electron beam based on the OTR distribution.
-The emittance of the HRRL was measured to be less than 0.4~$\mu$m using the OTR based tool at an energy of 15~MeV.  The details of this emittance measurement using quadrupole scanning method were described in the IPAC12 proceedings~\cite{setiniyaz-q-scan}. The results are summarized in Table~\ref{results}.
+The emittance of the HRRL was measured to be less than 0.4~$\mu$m using the OTR based tool at an energy of 15~MeV.  The details of this emittance measurement using the quadrupole scanning method were described in the IPAC12 proceedings~\cite{setiniyaz-q-scan}. The results are summarized in Table~\ref{results}.
 \begin{table}[hbt]

@@ Line 3: / Line 3: @@
 = text =
 %% The comment character in TeX / LaTeX is the percent character.
 %% The following chunk is called the header
@@ Line 109: / Line 108: @@
 \indent
-I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the HRRL. A polarized positron source, as a new probe to explore nuclear and particle physics at Jefferson Lab, is being studied at the Continuous Electron Beam Accelerator Facility (CEBAF). While their main mission is to optimize polarization, ISU's goal is to optimize positron production efficiency. Additionally, a  positron beamline at ISU is also potential tool for more nuclear physics studies. I have measured the emittance of the HRRL electron beam and constructed PMT bases for four NaI detectors. I will install the collection system and associated beam line components to measure the positron production efficiency using the HRRL.
+I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the HRRL. A polarized positron source, as a new probe to explore nuclear and particle physics at Jefferson Lab, is being studied at the Continuous Electron Beam Accelerator Facility (CEBAF). While their main mission is to optimize polarization, ISU's goal is to optimize positron production efficiency. Additionally, a positron beamline at ISU is also a potential tool for nuclear physics studies. I have measured the emittance of the HRRL electron beam and constructed PMT bases for four NaI detectors. I will install the collection system and associated beam line components to measure the positron production efficiency using the HRRL.
 \section{Previous Measurements}
 \indent
-Earlier positron production measurements were conducted at ISU's IAC in the May of 2008. The setup is shown in Fig.~\ref{fig:2008-pos-beamline} and the beamline elements are described in Table~\ref{tab:2008-pos-beamline-elements}. The accelerator was operated at a 300~Hz repetition rate and 10~MeV energy. Electrons were bent by the first dipole and sent to a 2~mm thick tungsten target. Any positrons produced were focused using two quadrupoles and bent 45 degrees by a second dipole which was set to transport 3~MeV positrons. Positrons were transported to the end of the linac where they annihilated in a Ta target. 511~keV photons were observed in both a HpGe and a NaI detector. Fig.~\ref{fig:2008-spectrum} shows the spectrum taken over a 600 second time interval.
+Earlier positron production measurements were conducted at ISU's IAC in the May of 2008. The setup is shown in Fig.~\ref{fig:2008-pos-beamline} and the beamline elements are described in Table~\ref{tab:2008-pos-beamline-elements}. The accelerator was operated at a 300~Hz repetition rate and 10~MeV energy. Electrons were bent by the first dipole and sent to a 2~mm thick tungsten target. Any positrons produced were focused using two quadrupoles and bent 45 degrees by a second dipole which was set to transport 3~MeV positrons. Positrons were transported to the end of the linac where they annihilated in a Ta target. A HpGe and a NaI detector were used to detect the 511~keV positrons produced as a result of annihilation. Fig.~\ref{fig:2008-spectrum} shows the spectrum taken over a 600 second time interval.
@@ Line 160: / Line 159: @@
-I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 1~kHz. The HRRL beamline had recently been reconfigured to generate and collect positrons, see Fig.~\ref{fig:HRRL-e+-line} and in Table~\ref{tab:hrrl}.
+I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 300~Hz. The HRRL beamline had recently been reconfigured to generate and collect positrons, see Fig.~\ref{fig:HRRL-e+-line} and Table~\ref{tab:hrrl}.
 \begin{table}[hbt]
@@ Line 183: / Line 182: @@
 \end{table}
-The new beamline was first designed by Dr. G. Stancari, to use a quadrupole triplet system to collect positrons~\cite{stancari}. The design was further optimized by Dr. Y Kim. The final design of the beamline is shown in Fig.~\ref{fig:HRRL-e+-line}. The HRRL accelerator room is divided into two parts by an L-shaped cement wall. The accelerator cell houses the cavity and other elements needed to transport electrons to an experimental cell. The experimental cell is located in an adjacent room to the accelerator cell. The HRRL beamline was reconfigured into an achromat by moving the accelerator cavity to accommodate two dipoles and a system of quadrupole magnets optimized for collecting positrons.
+The new beamline was first designed by Dr. G. Stancari to use a quadrupole triplet system to collect positrons~\cite{stancari}. The design was further optimized by Dr. Y Kim. The final design of the beamline is shown in Fig.~\ref{fig:HRRL-e+-line}. The HRRL accelerator room is divided into two parts by an L-shaped cement wall. The accelerator cell houses the cavity and other elements needed to transport electrons to an experimental cell. The experimental cell is located in a room adjacent to the accelerator cell. The HRRL beamline was reconfigured into an achromat by moving the accelerator cavity to accommodate two dipoles and a system of quadrupole magnets optimized for collecting positrons.
 In the new beamline, shown in Fig.~\ref{fig:HRRL-e+-line}, the electron beam exits the cavity and passes through a quadruple triplet  that will focus the electron beam onto the positron target. Positrons produced from the positron target will be collected by the second quadruple triplet that will be optimized to collect positrons. The first dipole magnet bends the positrons/electrons, depending on the magnet polarity, by 45 degrees towards the second dipole magnet. The second dipole will bend the beam another 45 degrees, thus completing a 90 degree bend. A third quadruple triplet will focus the e-/e+ beam, as users desire. All beam elements are described in Table~\ref{tab:new-hrrl-line-elements}.
@@ Line 242: / Line 241: @@
 An Optical Transition Radiation (OTR) based viewer was installed to allow measurements at the high electron currents available from the HRRL. The visible light from the OTR based viewer is produced when a relativistic electron beam crosses the boundary of two mediums with different dielectric constants.  Visible radiation is emitted at an angle of 90${^\circ}$ with respect to the incident beam direction~\cite{OTR} when the electron beam intersects the OTR target at a 45${^\circ}$ angle. These emitted photons are observed using a digital camera and can be used to measure the shape and intensity of the electron beam based on the OTR distribution.
-The emittance of the HRRL was measured to be less than 0.4~$\mu$m as using the OTR based tool at an energy of 15~MeV.  The details on this emittance measurement using quadrupole scanning method were described in the IPAC12 proceeding~\cite{setiniyaz-q-scan}. The results are summarized in Table~\ref{results}.
+The emittance of the HRRL was measured to be less than 0.4~$\mu$m using the OTR based tool at an energy of 15~MeV.  The details of this emittance measurement using quadrupole scanning method were described in the IPAC12 proceedings~\cite{setiniyaz-q-scan}. The results are summarized in Table~\ref{results}.
 \begin{table}[hbt]
@@ Line 271: / Line 270: @@
 \indent
-For detecting positrons, an annihilation target will be placed at the end of the 90 degree beamline. I want to use two NaI detectors to detect 511~keV photons.
+A tungsten target will be placed at the end of the 90 degree beamline to annihilate positrons. I want to use two NaI detectors to detect the 511~keV photons created when positrons annihilate. I acquired some NaI crystals from Idaho Accelerator Center (IAC). Since their original bases used a slow post-amplifier, I built new PMT bases. I modified the design of model PA-14 from Saint-Gobain Crystals \& Detectors Ltd. These detectors are tested, calibrated, and ready to be used for the measurement. Fig.~\ref{fig:IAC-dets} shows the crystals and the bases I built. Fig.~\ref{fig:IAC-dets-Co60-Na22-spec} shows the spectrum taken by the detector using button sources.
 %I expect by doing coincidence, the resolution of 511~keV peak in the spectrum will be improved.

@@ Line 104: / Line 104: @@
 \indent
-I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the High Repetition Rate Linac (HRRL) at Idaho State University's (ISU) Idaho Accelerator Center (IAC). Positrons were observed in May of 2008 at the IAC without the use of a quadrupole triplet collection system. When a 10~MeV electron beam used on the tungsten target, positrons escaping from the downstream side of the tungsten have a wide momentum spread of 0 to 2~MeV a large divergence of $\pi$ rad. A quad triplet collection system after the tungsten target is used to focus the positron beam and as a result increase our positron collection efficiency. I will install the collection system and associated beam line components and measure the positron production efficiency using the HRRL.}
+I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the High Repetition Rate Linac (HRRL) at Idaho State University's (ISU) Idaho Accelerator Center (IAC). Positrons were observed in May of 2008 at the IAC without the use of a quadrupole triplet collection system. When a 10~MeV electron beam is used on the tungsten target, positrons escaping from the downstream side of the tungsten have a wide momentum spread of 0 to 2~MeV and a large divergence of $\pi$ rad. A quad triplet collection system, after the tungsten target, is used to focus the positron beam and as a result increase our positron collection efficiency. I will install the collection system and associated beam line components and measure the positron production efficiency using the HRRL.}
 \section{Introduction}
 \indent
-I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the HRRL. A polarized positron source, as a new probe to explore nuclear and particle physics at Jefferson Lab, is being studied at the Continuous Electron Beam Accelerator Facility (CEBAF). While their main mission is to optimize polarization, ISU's, goal is to optimize positron production efficiency. Alternatively, a  positron beamline at ISU is also potential tool for more nuclear physics studies.I have measured the emittance of the HRRL electron beam and constructed PMT bases for four NaI detectors. I will install the collection system and associated beam line components to measure the positron production efficiency using the HRRL.
+I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the HRRL. A polarized positron source, as a new probe to explore nuclear and particle physics at Jefferson Lab, is being studied at the Continuous Electron Beam Accelerator Facility (CEBAF). While their main mission is to optimize polarization, ISU's goal is to optimize positron production efficiency. Additionally, a  positron beamline at ISU is also potential tool for more nuclear physics studies. I have measured the emittance of the HRRL electron beam and constructed PMT bases for four NaI detectors. I will install the collection system and associated beam line components to measure the positron production efficiency using the HRRL.
 \section{Previous Measurements}
 \indent
-Earlier positron production measurements were conducted at ISU's IAC in the May of 2008. The setup is shown in Fig.~\ref{fig:2008-pos-beamline} and the beamline elements are described in Table~\ref{tab:2008-pos-beamline-elements}. The accelerator was operated at a 300~Hz repetition rate and 10~MeV energy. electrons were bent by the first dipole, and sent to a 2~mm thick tungsten target. Positrons produced were focused using two quadrupoles and bent 45 degrees by a second dipole which was set to transport 3~MeV positrons. Positrons were transported to the end of the linac where they annihilated in a Ta target. 511~keV photons were observed in both a HpGe and a NaI detector. Fig.~\ref{fig:2008-spectrum} shows the spectrum taken over a 600 seconds.
+Earlier positron production measurements were conducted at ISU's IAC in the May of 2008. The setup is shown in Fig.~\ref{fig:2008-pos-beamline} and the beamline elements are described in Table~\ref{tab:2008-pos-beamline-elements}. The accelerator was operated at a 300~Hz repetition rate and 10~MeV energy. Electrons were bent by the first dipole and sent to a 2~mm thick tungsten target. Any positrons produced were focused using two quadrupoles and bent 45 degrees by a second dipole which was set to transport 3~MeV positrons. Positrons were transported to the end of the linac where they annihilated in a Ta target. 511~keV photons were observed in both a HpGe and a NaI detector. Fig.~\ref{fig:2008-spectrum} shows the spectrum taken over a 600 second time interval.
@@ Line 160: / Line 160: @@
-I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 1~kHz. The HRRL beamline had recently been reconfigured to generate and collect positrons, see Fig.~{fig:HRRL-e+-line} and in Table~\ref{tab:hrrl}.
+I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 1~kHz. The HRRL beamline had recently been reconfigured to generate and collect positrons, see Fig.~\ref{fig:HRRL-e+-line} and in Table~\ref{tab:hrrl}.
 \begin{table}[hbt]
@@ Line 183: / Line 183: @@
 \end{table}
-The new beamline was first designed by Dr. G. Stancari, it uses quadrupole triplet system to collect positrons~\cite{stancari}. The design was further optimized by Dr. Y Kim. The final design of the beamline is shown in Fig.~\ref{fig:HRRL-e+-line}. The HRRL accelerator room is divided into two parts by an L-shaped cement wall. The accelerator cell houses the cavity and other elements needed to transport electrons to an experimental cell. The experimental cell is located in an adjacent room to the accelerator cell. The HRRL beamline was reconfigured into an achromat by moving the accelerator cavity to accommodate two dipoles and a system of quadrupole magnets optimized for collecting positrons.
+The new beamline was first designed by Dr. G. Stancari, to use a quadrupole triplet system to collect positrons~\cite{stancari}. The design was further optimized by Dr. Y Kim. The final design of the beamline is shown in Fig.~\ref{fig:HRRL-e+-line}. The HRRL accelerator room is divided into two parts by an L-shaped cement wall. The accelerator cell houses the cavity and other elements needed to transport electrons to an experimental cell. The experimental cell is located in an adjacent room to the accelerator cell. The HRRL beamline was reconfigured into an achromat by moving the accelerator cavity to accommodate two dipoles and a system of quadrupole magnets optimized for collecting positrons.
 In the new beamline, shown in Fig.~\ref{fig:HRRL-e+-line}, the electron beam exits the cavity and passes through a quadruple triplet  that will focus the electron beam onto the positron target. Positrons produced from the positron target will be collected by the second quadruple triplet that will be optimized to collect positrons. The first dipole magnet bends the positrons/electrons, depending on the magnet polarity, by 45 degrees towards the second dipole magnet. The second dipole will bend the beam another 45 degrees, thus completing a 90 degree bend. A third quadruple triplet will focus the e-/e+ beam, as users desire. All beam elements are described in Table~\ref{tab:new-hrrl-line-elements}.
@@ Line 240: / Line 240: @@
 Emittance, a key parameter in accelerator physics, is used to quantify the quality of an electron beam produced by an accelerator. The beam size and divergence at any point in the beamline can be described using emittance and Twiss parameters.
-An Optical Transition Radiation (OTR) based viewer was installed to allow measurements at the high electron currents available using the HRRL. The visible light from the OTR based viewer is produced when a relativistic electron beam crosses the boundary of two mediums with different dielectric constants.  Visible radiation is emitted at an angle of 90${^\circ}$ with respect to the incident beam direction~\cite{OTR} when the electron beam intersects the OTR target at a 45${^\circ}$ angle. These emitted photons are observed using a digital camera and can be used to measure the shape and intensity of the electron beam based on the OTR distribution.
+An Optical Transition Radiation (OTR) based viewer was installed to allow measurements at the high electron currents available from the HRRL. The visible light from the OTR based viewer is produced when a relativistic electron beam crosses the boundary of two mediums with different dielectric constants.  Visible radiation is emitted at an angle of 90${^\circ}$ with respect to the incident beam direction~\cite{OTR} when the electron beam intersects the OTR target at a 45${^\circ}$ angle. These emitted photons are observed using a digital camera and can be used to measure the shape and intensity of the electron beam based on the OTR distribution.
-The emittance of the HRRL was measured to be less than 0.4~$\mu$m as using the OTR based tool at an energy of 15~MeV.  The details on this emittance measurement using quadrupole scanning method were described in the IPAC12 proceeding~\cite{setiniyaz-q-scan}. The results are summarized in table~\ref{results}.
+The emittance of the HRRL was measured to be less than 0.4~$\mu$m as using the OTR based tool at an energy of 15~MeV.  The details on this emittance measurement using quadrupole scanning method were described in the IPAC12 proceeding~\cite{setiniyaz-q-scan}. The results are summarized in Table~\ref{results}.
 \begin{table}[hbt]
@@ Line 272: / Line 272: @@
 For detecting positrons, an annihilation target will be placed at the end of the 90 degree beamline. I want to use two NaI detectors to detect 511~keV photons.
-I acquired some NaI crystals from Idaho Accelerator Center (IAC). Since their own bases used a slow post-amplifier, I built new PMT bases. I modified the design of model PA-14 from Saint-Gobain Crystals \& Detectors Ltd. These detectors are tested, calibrated, and ready to be used for the measurement. Fig.~\ref{fig:IAC-dets} shows the crystals and the bases I built. Fig.~\ref{fig:IAC-dets-Co60-Na22-spec} shows the spectrum taken by the detector using button sources.
+I acquired some NaI crystals from Idaho Accelerator Center (IAC). Since their original bases used a slow post-amplifier, I built new PMT bases. I modified the design of model PA-14 from Saint-Gobain Crystals \& Detectors Ltd. These detectors are tested, calibrated, and ready to be used for the measurement. Fig.~\ref{fig:IAC-dets} shows the crystals and the bases I built. Fig.~\ref{fig:IAC-dets-Co60-Na22-spec} shows the spectrum taken by the detector using button sources.
 %I expect by doing coincidence, the resolution of 511~keV peak in the spectrum will be improved.

@@ Line 2: / Line 2: @@
-=text =
+= text =
 %% The comment character in TeX / LaTeX is the percent character.
 %% The following chunk is called the header
@@ Line 103: / Line 104: @@
 \indent
-I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the High Repetition Rate Linac (HRRL) at Idaho State University's (ISU) Idaho Accelerator Center (IAC). Positrons were observed in May of 2008 at the IAC without the use of a quadrupole triplet collection system. Positrons escaping from the downstream side of the tungsten target have a wide momentum spread of 0 to 2~MeV when using a 10~MeV electron beam and a large divergence of $\pi$ rad. A second quad triplet collection system is used to focus the positron beam and as a result increase our positron collection efficiency. I will install the collection system and associated beam line components to measure the positron production efficiency using the HRRL.}
+I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the High Repetition Rate Linac (HRRL) at Idaho State University's (ISU) Idaho Accelerator Center (IAC). Positrons were observed in May of 2008 at the IAC without the use of a quadrupole triplet collection system. When a 10~MeV electron beam used on the tungsten target, positrons escaping from the downstream side of the tungsten have a wide momentum spread of 0 to 2~MeV a large divergence of $\pi$ rad. A quad triplet collection system after the tungsten target is used to focus the positron beam and as a result increase our positron collection efficiency. I will install the collection system and associated beam line components and measure the positron production efficiency using the HRRL.}
 \section{Introduction}
 \indent
-I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the HRRL. A polarized positron source, as a new probe to explore nuclear and particle physics at Jefferson Lab, is being studied at the Continuous Electron Beam Accelerator Facility (CEBAF). While their main mission is to optimize polarization, ISU's, goal is to optimize positron production efficiency. On the other hand, positron beamline at ISU is also potential tool for more nuclear physics studies. 4 NaI detectors available for positron detection, and I have measured the emittance of the electron beam optimization. I will install the collection system and associated beam line components to measure the positron production efficiency using the HRRL.
+I propose to measure the positron production efficiency for a positron source that uses a quadrupole triplet system to collect positrons from a tungsten target that are produced when the target is impinged by electrons from the HRRL. A polarized positron source, as a new probe to explore nuclear and particle physics at Jefferson Lab, is being studied at the Continuous Electron Beam Accelerator Facility (CEBAF). While their main mission is to optimize polarization, ISU's, goal is to optimize positron production efficiency. Alternatively, a  positron beamline at ISU is also potential tool for more nuclear physics studies.I have measured the emittance of the HRRL electron beam and constructed PMT bases for four NaI detectors. I will install the collection system and associated beam line components to measure the positron production efficiency using the HRRL.
 \section{Previous Measurements}
 \indent
-Earlier measurements were conducted at ISU's IAC in the May of 2008. The setup is shown in Fig.~\ref{fig:2008-pos-beamline} and the beamline elements are described in Table~\ref{tab:2008-pos-beamline-elements}. The accelerator was operated at a 300~Hz repetition rate and 10~MeV energy. The electron was bent by the first dipole, and sent to a 2~mm thick tungsten target. Positrons produced were focused using two quadrupoles and bent 45 degree by the second dipole which was set to transport 3~MeV positrons. Positrons were transported to the end of the linac where they annihilated in Ta target. 511~keV photons were observed in both HpGe and NaI detectors. Fig.~\ref{fig:2008-spectrum} shows the spectrum was taken over 600 seconds.
+Earlier positron production measurements were conducted at ISU's IAC in the May of 2008. The setup is shown in Fig.~\ref{fig:2008-pos-beamline} and the beamline elements are described in Table~\ref{tab:2008-pos-beamline-elements}. The accelerator was operated at a 300~Hz repetition rate and 10~MeV energy. electrons were bent by the first dipole, and sent to a 2~mm thick tungsten target. Positrons produced were focused using two quadrupoles and bent 45 degrees by a second dipole which was set to transport 3~MeV positrons. Positrons were transported to the end of the linac where they annihilated in a Ta target. 511~keV photons were observed in both a HpGe and a NaI detector. Fig.~\ref{fig:2008-spectrum} shows the spectrum taken over a 600 seconds.
@@ Line 159: / Line 160: @@
-I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 1~kHz. The HRRL beamline had recently been reconfigured to generate and collect positrons. More details about the HRRL are shown in Table~\ref{tab:hrrl}.
+I propose a measurement of the positron production efficiency using the HRRL. The HRRL can provide electron beams with energies between 3~MeV and 16~MeV, and a maximum repetition rate of 1~kHz. The HRRL beamline had recently been reconfigured to generate and collect positrons, see Fig.~{fig:HRRL-e+-line} and in Table~\ref{tab:hrrl}.
 \begin{table}[hbt]
@@ Line 184: / Line 185: @@
 The new beamline was first designed by Dr. G. Stancari, it uses quadrupole triplet system to collect positrons~\cite{stancari}. The design was further optimized by Dr. Y Kim. The final design of the beamline is shown in Fig.~\ref{fig:HRRL-e+-line}. The HRRL accelerator room is divided into two parts by an L-shaped cement wall. The accelerator cell houses the cavity and other elements needed to transport electrons to an experimental cell. The experimental cell is located in an adjacent room to the accelerator cell. The HRRL beamline was reconfigured into an achromat by moving the accelerator cavity to accommodate two dipoles and a system of quadrupole magnets optimized for collecting positrons.
-In the new beamline, shown in Fig.~\ref{fig:HRRL-e+-line}, the electron beam from the cavity passes first through a quadruple triplet  that will focus the electron beam onto the positron target. Positrons produced from the positron target will be collected by the second quadruple triplet that will be optimized to collect positrons. The first dipole magnet bends the positrons/electrons, depending on the magnet polarity, by 45 degrees towards the second dipole magnet. The second dipole will bend the beam another 45 degrees, thus completes a 90 degree bend. A third quadruple triplet will focus the e-/e+ beam, as users desire. All beam elements are described in Table~\ref{tab:new-hrrl-line-elements}.
+In the new beamline, shown in Fig.~\ref{fig:HRRL-e+-line}, the electron beam exits the cavity and passes through a quadruple triplet  that will focus the electron beam onto the positron target. Positrons produced from the positron target will be collected by the second quadruple triplet that will be optimized to collect positrons. The first dipole magnet bends the positrons/electrons, depending on the magnet polarity, by 45 degrees towards the second dipole magnet. The second dipole will bend the beam another 45 degrees, thus completing a 90 degree bend. A third quadruple triplet will focus the e-/e+ beam, as users desire. All beam elements are described in Table~\ref{tab:new-hrrl-line-elements}.
@@ Line 237: / Line 238: @@
-Emittance, a key parameter in accelerator physics, is used to quantify the quality of an electron beam produced by an accelerator. The beam size and divergence at any point in the beamline can he obtained using emittance and Twiss parameters by simulation.
+Emittance, a key parameter in accelerator physics, is used to quantify the quality of an electron beam produced by an accelerator. The beam size and divergence at any point in the beamline can be described using emittance and Twiss parameters.
 An Optical Transition Radiation (OTR) based viewer was installed to allow measurements at the high electron currents available using the HRRL. The visible light from the OTR based viewer is produced when a relativistic electron beam crosses the boundary of two mediums with different dielectric constants.  Visible radiation is emitted at an angle of 90${^\circ}$ with respect to the incident beam direction~\cite{OTR} when the electron beam intersects the OTR target at a 45${^\circ}$ angle. These emitted photons are observed using a digital camera and can be used to measure the shape and intensity of the electron beam based on the OTR distribution.
@@ Line 270: / Line 271: @@
 \indent
-For detecting positrons, an annihilation target will be placed at the end of the 90 degree beamline. I want to use NaI detectors to detect 511~keV photons.
+For detecting positrons, an annihilation target will be placed at the end of the 90 degree beamline. I want to use two NaI detectors to detect 511~keV photons.
-I acquired some NaI crystals from Idaho Accelerator Center (IAC). Since their own bases relied on slow post-amplification, I built new PMT bases. I modified the design of model PA-14 from Saint-Gobain Crystals \& Detectors Ltd. These detectors are tested, calibrated, and ready to be used for the measurement. Fig.~\ref{fig:IAC-dets} shows the crystals and the bases I built. Fig.~\ref{fig:IAC-dets-Co60-Na22-spec} shows the spectrum taken by the detector using button sources.
+I acquired some NaI crystals from Idaho Accelerator Center (IAC). Since their own bases used a slow post-amplifier, I built new PMT bases. I modified the design of model PA-14 from Saint-Gobain Crystals \& Detectors Ltd. These detectors are tested, calibrated, and ready to be used for the measurement. Fig.~\ref{fig:IAC-dets} shows the crystals and the bases I built. Fig.~\ref{fig:IAC-dets-Co60-Na22-spec} shows the spectrum taken by the detector using button sources.
 %I expect by doing coincidence, the resolution of 511~keV peak in the spectrum will be improved.

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