CHIPS Run Feb-2008 - Revision history

Oborn: /* Analysis */

2008-04-05T20:29:54Z

Analysis

2008-03-13T19:37:48Z

Beam Profile

2008-03-08T01:49:13Z

Analysis

2008-03-08T01:32:41Z

Analysis

2008-03-08T01:25:07Z

Analysis

2008-03-08T00:56:08Z

Analysis

2008-03-08T00:37:37Z

02-29-08

2008-03-03T22:22:45Z

Beam Profile

2008-03-03T22:19:40Z

Beam Profile

2008-02-28T17:39:46Z

02-29-08

← Older revision		Revision as of 20:29, 5 April 2008
Line 230:		Line 230:
	(25 positrons)/(4e14 electrons) = 6.e-13 positrons/electrons.		(25 positrons)/(4e14 electrons) = 6.e-13 positrons/electrons.
	This yield is so low that it could all be secondary positrons from gammas hitting the beam pipe.		This yield is so low that it could all be secondary positrons from gammas hitting the beam pipe.
		+
		+
		+
		+	[http://www.iac.isu.edu/mediawiki/index.php/Positrons Go back]

@@ Line 38: / Line 38: @@
 ----
 Analysis of exposed glass plate.   Glass plate exposed to 4mA of beam current, positioned at exit of straight ahead section on D2.
 Raw Image:

← Older revision		Revision as of 01:49, 8 March 2008
Line 227:		Line 227:

	(25 positrons)/(4e14 electrons) = 6.e-13 positrons/electrons.		(25 positrons)/(4e14 electrons) = 6.e-13 positrons/electrons.
		+	This yield is so low that it could all be secondary positrons from gammas hitting the beam pipe.

← Older revision		Revision as of 01:32, 8 March 2008
Line 223:		Line 223:
	ADC11 saturated/overflow from channel 3800 (4 MeV).		ADC11 saturated/overflow from channel 3800 (4 MeV).
	Need to remove amplifier gain of 50 to reduce 87 MeV signal to channel 1700		Need to remove amplifier gain of 50 to reduce 87 MeV signal to channel 1700
		+
		+	4 mA beam at 60 Hz = 4mC/(60 burst) = (4.e-3 C) / (60 burst * 1.6e-19 C/e-) = 4.e14 e-/burst
		+
		+	(25 positrons)/(4e14 electrons) = 6.e-13 positrons/electrons.

@@ Line 189: / Line 189: @@
 Relative intensity (Beam photons above 1 MeV)/(Beam Positrons) = (5058/ (50% relative detection probability) ) / 22090
 Relative intensity = 0.5
 Of the 22090 coincidence events roughly 17000 were positrons in beam
@@ Line 199: / Line 205: @@
 From the 0.5 relative gamma/positron intensity, we
 extrapolate a photon intensity above 1 MeV = 12 gamma/burst
 gamma peak in ADC at around channel 500

@@ Line 176: / Line 176: @@
 =Analysis=
+CEH & SG
 Run 407.
 % of charged particles less than 10MeV/c should be deflected by magnet into wall before target/detector in
@@ Line 188: / Line 188: @@
 Run 407 number of positron annihilation candidates                =  5058
 Relative intensity (Beam photons above 1 MeV)/(Beam Positrons) = (5058/ (50% relative detection probability) ) / 22090
-                   = 0.5
+Relative intensity = 0.5

← Older revision		Revision as of 00:37, 8 March 2008
Line 173:		Line 173:

	Run 409 : Changed the setting from coincidence to straight ahead measurement. Jlab NaI was put on the beamline.		Run 409 : Changed the setting from coincidence to straight ahead measurement. Jlab NaI was put on the beamline.
		+
		+
		+	=Analysis=
		+
		+	Run 407.
		+	100% of charged particles less than 10MeV/c should be deflected by magnet into wall before target/detector in
		+	experimental cell.
		+	Target in Exp cell = 4 in Al = approx 1 Radiation length
		+	Probability of conversion of photon above 1 MeV to e+e- pair = 1-exp(X/X0) approx 60%
		+	dEdX in Al = 1.6 MeV/cm. All positrons produced in first 8cm of Al will stop in Al == 80% positron annihilation probability.
		+	Target X coinc NaI configuration, run 406 & 407
		+	Ratio (Detection efficiency for beam photons of energy > 1.0 MeV)/(Beam positron detection efficiency) = (0.6)*(0.8) = 50%
		+	Run 406 number of positron annihilation candidates (ADC7 X ADC11) = 22090
		+	Run 407 number of positron annihilation candidates = 5058
		+	Relative intensity (Beam photons above 1 MeV)/(Beam Positrons) = (5058/ (50% relative detection probability) ) / 22090
		+	= 0.5

@@ Line 41: / Line 41: @@
 Raw Image:
-[[Image:scanned_glass_image.tif]]
+[[Image:scanned_glass_image.jpg]]
 Projections and fits:

← Older revision		Revision as of 22:19, 3 March 2008
Line 33:		Line 33:

	[[Image:BeamProfile_2-26-08_3.jpg \| 400 px]]		[[Image:BeamProfile_2-26-08_3.jpg \| 400 px]]
		+
		+
		+
		+	----
		+	Analysis of exposed glass plate. Glass plate exposed to 4mA of beam current, positioned at exit of straight ahead section on D2.
		+
		+	Raw Image:
		+
		+	[[Image:scanned_glass_image.tif]]
		+
		+	Projections and fits:
		+
		+	[[Image:plate_fits.jpg]]

	==Beam on ==		==Beam on ==

← Older revision		Revision as of 17:39, 28 February 2008
Line 155:		Line 155:
	HV: 1300/1500		HV: 1300/1500
	Coincidence Rate: 360 cnts/60secs		Coincidence Rate: 360 cnts/60secs
		+
		+	Run 408 : Skipped due to overflow
		+
		+
		+	Run 409 : Changed the setting from coincidence to straight ahead measurement. Jlab NaI was put on the beamline.