# Presentation: 136037

## UPDATE ON THE

_**FORWARD PROTON DETECTOR**_

-  Gilvan Alves
-   Lafex/CBPF

- Introduction
- Accelerator
- Roman Pots
- Detector
- Future Plans
***          ******	***

**April 1, 1998 (no kidding)**

## Series of 18 Roman Pots forms 9 independent

** ****spectrometers 1 Dipole Spectrometer ( ****p**** ) ********min**
** ****8 Quadrupole Spectrometers  ****(****p****  or **** p****,  up or down,**
** ****left or right)**** t > t****min**

**Q****4**

**D**

**Q****1**

** ****S**

**Q****2**

**Q****2**

**Q****3**

**Q****3**

**Q****4**

**S**

**A****1Q**

**A****1S**

**A****2Q**

**A****2S**

**P****1Q**

**P****2S**

**P****1S**

**P****2Q**

**p**

**p**

**59   57   36     31          23    19   13   7             0            7   13   19     23         31   **
**	****	****	****	****	****	****         ****Z(m)**

**A****D2**

**A****D1**

**  ****Detector**

**  ****Bellows**

** ****Roman**
**    ****Pot**

_***FORWARD  PROTON DETECTOR***_

## Diffractive Kinematics

-  Rapidity Gap Approach
-  Need to Tag and Measure p( p )

**  **

**  **

** **

**Detector**

- p

## The Detector 

- 0.8mm

- The Detector

- UVX Planes

##   PROPOSAL FOR A FORWARD

_**PROTON DETECTOR  AT DZERO**_** **
**	****	****	**_**(P-900)**_

-  Andrew Brandt
-        FNAL/

- 1) PHYSICS MOTIVATION
- 2) FPD DETAILS
***          ***
***	***

**Fermilab PAC meeting**
**Fermilab**
**October  17, 1997**

## ACCELERATOR MODIFICATIONS

_**ACCELERATOR MODIFICATIONS**_

- 1)  Move low beta quadrupoles ~ 2/3  meter
-       closer to the interaction point.
-       Requires modified quadrupole supports.
- 2)   Insert pots in electrostatic separator region.
-        Requires bypass extension.

- Bypass extended

## ACCELERATOR MODIFICATIONS

- 3) Dipole Spectrometer does not require
-     modifications   Warm section exists.
-  Feasibility and Cost Studies done in conjunction
-     with Beams Division (see Memo).
-  No interference with Tevatron operation
-  Total Cost  $500k (Mostly Engineering Labor).
-  An Engineer from Brazil will work with the
-     AD on the modifications.
-  Mike Martens has joined the FPD group and
-     will act as the Beams Division Liaison Person
-     for this project.

## FRONT VIEW OF PROPOSED 

**              **_**ROMAN POTS**_

## SIDE VIEW: CROSS SECTION

## Full Scale Model Presented at

_**Lishep98 - Rio**_

## Full Scale Model Presented at

_**Lishep98 - Rio**_

## Full Scale Model Presented at

_**Lishep98 - Rio**_

## Further Development in Progress

-  Reducing Pot “Long Neck” Size
-  Interface with Pumping Devices
-  Chainless Design

- Agreement Signed with LNLS for
-   Prototype building this spring
-   LNLS - National Synchrotron Lab
-  Helps on Funding
-  Prague group is Helping with
-       design & Vacuum expertise

## THE DETECTOR

- (u,u’,v,v’,x,x’)
- of 800 
- scintillator
- fibers (’) planes
- offset by 2/3
- fiber

_**THE DETECTOR**_

- 20 channels/plane(U,V)’
- 16 channels/plane(X,X’)
- 112 channels/detector
- 2016 total channels
- 80  theoretical resolution

## THE DETECTOR

- 4 Fiber bundle
- fits well the
- pixel size of
- H6568 16 Ch.
- MAPMT
- 7 PMT’s/detector
- (most of the cost)

_**THE DETECTOR**_

**U**

**U’**

## Slide 16

## Photon Detection Device

- Quantum Efficiency
- Light  Charge
-  VLPC ( 80%)
-  APD ( 70%)
-  Image Intensifier
-  	CCD ( 20%)
- 	Low rate
-   MAPMT ( 20%)
- VLPC the best option
- But... cryogenics$$$

_**DETECTOR OPTIONS**_

- Fiber Options Investigated
-  Scint. Tile to Clear Fiber
-  Scint. Tile to WLS Fiber
-  Scint. Fiber Straight
-  Scint. Fiber to Clear Fiber
-  Round vs. Square Fibers

_**DETECTOR OPTIONS**_

- Scint Tile
- 800m thick

- Clear Fiber

- 4fibers  PMT

- 2 WLS fibers  PMT

_**DETECTOR OPTIONS**_

- Scint Fibers
- 800m

- Mirrored side

- Mirrored side

- 4fibers  PMT

- 4fibers  PMT

## Slide 21

## Single PE

- Measurement
- H6568

- Scint. Tile
- +
- Clear Fiber

- <NPE>=3.0

- LED Calibration.

## Scint.  Fiber

- Output
- H6568

- Effect of cutting
-  Fiber at 45

- <NPE>=7.3

- <NPE>=6.8

## Similar to Uncut Straight Fibers

- Gain              Attenuation length
- Losses due to
-  Cutting Fiber at 45 (5%)
-  Fiber Splicing (5-10%)
-  Preferred Option
-  Accelerator Background
-  Cross Talk

- Scint.  Fiber
- + Clear Fiber
- Output
- H6568

- <NPE>=7.4

## Current Developments

-  0th order Fiber detector Prototype being tested
-  DAQ for prototype testing has been assembled
-  Modifications to Splicing Machine being made
-  Work on adapting CFT Trigger System
-  Work on FPD Trigger strategy in progress

## Slide 26

## Slide 27

## 1998 Plans

-  Finalizing Detector and Pot Designs
-  Both Prototypes Ready by Fall
-  Request for National Grant within Brazil
-  Project Integration within accelerator and D