Difference between revisions of "Solid Target Shift"

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(Created page with "== The Solid Target == The solid target is primarily meant for commissioning purpose. It consists of a support cart, an outer Al tube and an inner plastic nylon tube open to...")
 
(Change between Full and Empty Targets)
 
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== The Solid Target ==
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== Description of Solid Target for CPP-NPP ==
  
The solid target is primarily meant for commissioning purpose. It consists of a support cart, an outer Al tube and an inner plastic nylon tube open to air and terminated by a removable cap of 3.19 cm internal diameter. The cap can be either:
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* The 208Pb target, manufactured by Oak Ridge National Laboratory, is a 1-in.-diameter circular foil of 99.09% enriched 208Pb, with an approximate thickness of 12 mils.
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* A description of the target can be found in [https://doi.org/10.1016/j.nima.2009.09.063 P. Martel et al., "Nuclear Targets for a Precision Measurement of the Neutral Pion Radiative Width," NIMA 612 (2009) 46-49.]
  
* 10mm disk of CH2 (HDPE, high density polyethylene)
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Material near the target consists of the following:
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* exit beam pipe window: 125um Kapton
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* distance from exit beam pipe window and target: ~3cm
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* distance from lead target to entrance He bag: ~1cm
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* entrance and exit window He bag: 50um aluminized mylar
  
* 2mm disk  CH2 (HDPE)
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== Change between Full and Empty Targets ==
  
* CH2 (HDPE) cup of 2mm thickness for the 2cm-inner diameter and 7mm for the outer ring.
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The target holder has two positions:
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* Full (208Pb) - YELLOW FLAG (Tape) UP
* 3.4mm C12 graphite disk
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* Empty Target Frame - YELLOW FLAG BEAM LEFT
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Changes between the two configurations requires an access to the hall, which may be conducted in Rapid Access Mode. Changes between the configurations should be performed by personnel familiar with the procedure:
  
* Al. cross made of 1.59 mm diameter wires
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* [https://halldweb.jlab.org/DocDB/0056/005638/001/CPP_Lead_Target_Change_Procedure_v1.pdf Change from Full to Empty Target]
  
* 1cm long Al. cylinder with an equilateral triangle hole inside. The triangle edge lengths are 2.5 cm
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The position of the flag indicating the target position can be viewed using the camera in Hall D from the west wall. The camera can be accessed from [[Slow Controls Shift#Cameras in the halls | Cameras in Hall D]].  
  
The position of the cap with respect to the nominal center can be moved 12 cm downstream or 32 cm upstream.
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[[File:lead_target.gif | 200px]]
  
== Routine Operation ==
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== Original Solid Targets from 2014 ==  
  
There is no remote control for the target. Changing configuration (i.e. changing cap type or cap position) requires an access and a manual change and will be performed by experts.
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Note: Documentation of original Hall D target in 2014 can be found in the deprecated pages [[Solid Target Shift Original]]
 
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[[Procedure installing solid target | Instructions to install/change the solid target]]
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[https://halldweb1.jlab.org/wiki/index.php/Target_Conditions Table with target history]
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== Expert personnel ==
 
== Expert personnel ==
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{| border=1  
 
{| border=1  
|+ Table:  Expert personnel for the Cryogenic Target
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|+ Table:  Expert personnel for the CPP-NPP Solid Target
 
|- bgcolor=#DFDFDF   
 
|- bgcolor=#DFDFDF   
 
! width=200px | Name    !!  width=100px | Extension !! Date of qualification  
 
! width=200px | Name    !!  width=100px | Extension !! Date of qualification  
 
|-
 
|-
| Alexandre Deur  (1st contact) ||  align=center | Office: 757-269-7526 / Cell: 757-871-5931   ||  align=center | June 12, 2014
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| Tim Whitlatch ||  align=center | Office: 757-269-5087   ||  align=center | June 10, 2022
|-
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| Mark Ito  (2nd contact)        ||  align=center | Office: 757-269-5295 / Cell  757-504-0664 ||  align=center | June 12, 2014
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  |}
 
  |}

Latest revision as of 10:05, 10 June 2022

Description of Solid Target for CPP-NPP

Material near the target consists of the following:

  • exit beam pipe window: 125um Kapton
  • distance from exit beam pipe window and target: ~3cm
  • distance from lead target to entrance He bag: ~1cm
  • entrance and exit window He bag: 50um aluminized mylar

Change between Full and Empty Targets

The target holder has two positions:

  • Full (208Pb) - YELLOW FLAG (Tape) UP
  • Empty Target Frame - YELLOW FLAG BEAM LEFT

Changes between the two configurations requires an access to the hall, which may be conducted in Rapid Access Mode. Changes between the configurations should be performed by personnel familiar with the procedure:

The position of the flag indicating the target position can be viewed using the camera in Hall D from the west wall. The camera can be accessed from Cameras in Hall D.

Lead target.gif

Original Solid Targets from 2014

Note: Documentation of original Hall D target in 2014 can be found in the deprecated pages Solid Target Shift Original

Expert personnel

The individuals responsible for checking that the solid target is ready to take data and setting its operating parameters are shown in following table. Additional experts may be trained by the system owner and their name and date added to this table.


Table: Expert personnel for the CPP-NPP Solid Target
Name Extension Date of qualification
Tim Whitlatch Office: 757-269-5087 June 10, 2022