# Presentation: 396419

## Preliminary Design Review forThe SNS Video Profile Monitor System Dave GassnerBrookhaven National Laboratory

- Part II:  System Design

## Part II. System Design

**Mechanical designs by:**
- J. Brodowski (Beamline components)
- S. Bellavia (Camera, ND filter, lens, lamp, mount)
**Based on experience at RHIC, BAF, & AGS fixed target systems.**
**Radiation hardened components.**

- SNS VPM PDR

- July 24, 2002

## VPM Block Diagram

***VPM Block Diagram***

**Video Camera**

**Lens**

**Neutral **
**Density **
**Filter**

**Illumination **
**Lamps**

**Object**

**Quartz**
**Port**

**Rack In Ring **
**Service Building**

**Framegrabber**

**Camera CCU**

**ND Filter Cntrl**

**Lamp Control**

**Network**

- SNS VPM PDR

- July 24, 2002

## SNS VPM Layout

**Primary (thin) Foil Camera Cubby**

**Secondary (thick) Foil Camera Cubby**

**HEBT**
**Beam**

- _Estimated Radiation levels_
- The main cause of loss at
- injection will be nuclear
- scattering at the thin carbon foil.
- Uncontrolled loss = 2.5W/m
-  Produces about 250 R/hr at 1 ft.

**Camera to foil distance 5 meters**

**SNS/AP Tech note 7**

**Est. Camera Dose 10’s kR/year **

- SNS VPM PDR

- July 24, 2002

## Primary Stripping Foil Assembly

_**Phosphor Screen:**_
**Al****2****O****3****, Morgan Matroc, Chromox-6**
**1mm thick**
**Fiducials for frame grabber reference.**

_**Stripping Foil: **_
** ****Foil 1 micron thick will heat up to > 2000K.**
**1.5” long by 0.5” tall.  **
**Object (beam) will be 0.5” x 0.5” (end of foil) **
**Viewed via 2.5” ID quartz port at 40****o****.**

- SNS VPM PDR

- July 24, 2002

## Secondary Stripping Foil Assembly

***Secondary Stripping Foil Assembly***

_**Secondary foil:**_** **
- 	10mils Carbon-carbon, 3.5” wide
- 	2.5” ID quartz port at 40o
- 	View is ellipse 3.125” wide, 2.375 tall.
- 	The 2 beams H- & H0 are 2.125” apart on center
_**Phosphor Screen:**_
-  Al2O3, Morgan Matroc, Chromox-6,
-  1mm thick
-  Fiducials for frame grabber reference.

- SNS VPM PDR

- July 24, 2002

## SNS Video Foil Hardware

**  **

**Neutral density filter assembly (C-AD):**
** ****DC motor drive**
** ****Geneva gear with chain**
** ****6 positions (blank, 1, 2, 3, 4, 5)**

**Dage 70RV camera, ND filter, lens assembly **
**on rails inside cubby recessed in nearby wall.**

- The cubby hole, camera mount, with drawer slides.

- SNS VPM PDR

- July 24, 2002

## Radiation Hardened Components

**Video Camera**
- Dage-MTI 70RVH - Monochrome
- Vacuum tube based camera head (no solid state).
- Separated camera head & camera control unit.
- AGC & Auto pedestal (black) loops in manual mode.
- Designed for BNL, used at g-2 target, 60 X 1012 protons at 28 GeV.
- 10 M-Rads, no failures.
**Neutral Density Filter, BNL design –Rad hard design.**
**Camera Lens, Fujinon – Mega-Rad dose, 10% transmission loss.**
**Vacuum port, quartz – Most Rad-hard material.**

**Vacuum Tube**

**Newvicon Video Tube**

**Newvicon Spectral Response**

- SNS VPM PDR

- July 24, 2002

## Foil Temperature & Wavelength

***Foil Temperature & Wavelength***

**Newvicon tube**
**Spectral Response**

**SNS Primary stripping foil reaches equilibrium **
**temperature 2000K, after about 20us. **

**1000nm**

**200nm**

- SNS VPM PDR

- July 24, 2002

## Response & Timing

_**Response Characteristics:**_
**Screen: **
**	****Time constant = 10’s of ms**
**	****Fluorescence wavelength 700 – 900 nm**
**	****Radiation Resistance about 1 x 10****20**** p/cm****2**** (C Johnson, CERN)**
**Newvicon Tube:**
**	****Time constant = 10’s of ms**
**	****Saturation recovery = 100’s of ms**
**Stripping Foil design continues.**
**	**
_**System Timing:**_
- Standard RS-170 Video, interlaced:
**1 frame every 1/30 second (33ms)**
**1 field every 1/60 second** **(16.6ms)**
- May need to phase shift camera synch to line synch.

- SNS VPM PDR

- July 24, 2002

## Frame Grabber

- Baseline originally specified a VME based Framegrabber
- Imaging Technology Inc. MVC 150/40 Pipeline Vision Processing
- Processed 512 X 512 image in < 7.5msec.
- no longer available.
**Coreco Imaging, Viper Series, key features**
**PCI bus Image transfers at 110 Mbytes/sec.**
**Pixel processor performs **_**real-time image preprocessing**_**, ****8 bits/pixel.**
**Features trigger input, strobe output, integration and digital I/O**

- SNS VPM PDR

- July 24, 2002

## VPM System I/O

**Time stamped processed images:**
**Foils**
**Phosphor screens**
**Detailed time history**
**Neutral Density Filter Setting & Readback**
**Timing: (delayed) line synch**
**Lamp Control**

- SNS VPM PDR

- July 24, 2002

## SNS Video Profile Monitor Data

_**Resolution Estimate:**_
**RS-170 video, 512 x 480 pixel frame **
**grabber, 8 bits.  Using Celestron G5 **
**Schmidt-Cassegrain lens (1250mm **
**focal length),  we can get at least 10 **
**pixels/mm.**
_**Object Details:**_
_**Primary foil:**_** 1 micron thick foil will **
**heat up to > 2000K.**
**1.5” long by 0.5” tall.  Object will be**
**0.5” x 0.5” (end of foil) viewed via **
**2.5” ID quartz port at 40****o****.**
_**Secondary foil:**_** 10mils Carbon-carbon.  3.5” wide, 2.5” ID quartz port at 40****o****.  We will see an ellipse 3.125” wide, 2.375 tall. The 2 beams H****-**** & H****0**** are 2.125” apart on center.**

**Frame grabber data (AGS to RHIC transport) **
**showing profile projections.  Neutral density **
**filter can be inserted to avoid saturation.**

- SNS VPM PDR

- July 24, 2002

## Summary

_** **_
-    **Primary and secondary stripping foil** **light analyzed.**
**   ****Two rad-hard video camera systems with image processing electronics.**
**   ****Phosphor screens for profile measurements (at reduced machine intensity).**
**   ****Illumination foils with lamp for visual inspection.**
_**What is next:**_
-   ** ****Design System**
**   ****Investigation of the light emitted from the foils.**
**   ****Evaluate components.**
** **

- SNS VPM PDR

- July 24, 2002