# Presentation: 402127

## Single-Photon Detection with MicroChannel Plate Based Photo Multiplier Tubes

**John Martin, Paul Hink**
**BURLE INDUSTRIES, INC.**
**Workshop on Single-Photon: Detectors, Applications and Measurement Methods.**
**NIST, Gaithersburg, MD**

- NIST Single Photon Detector Workshop

- 31 March 03

## MCP-PMT Operation

- Faceplate
- Photocathode

- Dual MCP

- Anode

- Gain ~ 106

- Photoelectron

- V ~ 300V

- V ~ 300V

- V ~ 3000V

- photon

- NIST Single Photon Detector Workshop

- 31 March 03

## MCP-PMT Developments

**1.****	**_***GaAs MCP-PMT***__**, 18mm Round**_
**	****85104-500****	****Standard MCP PMT**
**	****85104-540****	****Gated MCP PMT**
**5********m pore size, 60:1 L/D Ratio**
**2.****	**_***Planacon***__***TM***__**, **__**2” Square**_** **
**	****85001****	****	****2x2 Array**
**	****85011****	****	****8x8 Array**
**25mm pore size, 40:1 L/D Ratio**

- NIST Single Photon Detector Workshop

- 31 March 03

## GaAs MCP-PMT (85104)

**18 mm dual MCP.**
**Very high cathode sensitivity (>1200 ********A/lm).**
**Excellent red response (>20% QE at 850nm).**
**Excellent photon counting properties (peak-valley > 2:1).**
**Low dark count rate (<200cps @ -30****o****C.)**

- NIST Single Photon Detector Workshop

- 31 March 03

## Spectral Response 	GaAs MCP-PMT

**Cathode Luminous Sensitivity** **...**
- >1200 A/lm Min.
- 1500 A/lm Typ.
**Excellent QE...**
- ~30% at 600nm
- > 20% at 850nm
- > 20% at 370nm

- NIST Single Photon Detector Workshop

- 31 March 03

## InGaAs Spectral Response 	 GaAs MCP-PMT

- NIST Single Photon Detector Workshop

- 31 March 03

## Gain Curves	 GaAs MCP-PMT

**Typical Tube Gain...**
- > 5x106

- NIST Single Photon Detector Workshop

- 31 March 03

## Single Electron Resolution	 GaAs MCP-PMT

**At tube Gain > 5x10****5**
- Peak:Valley > 2:1
- Dark counts < 200 cps.
**At tube Gain > 1x10****6**
- Typical SER < 150%
- (*SER*= FWHM/Peak)

- light

- dark

**SER** = 134%

- NIST Single Photon Detector Workshop

- 31 March 03

## Single Electron Spectrum	 GaAs MCP-PMT

- At higher gains ability to distinguish 1pe and 2pe peaks.

- NIST Single Photon Detector Workshop

- 31 March 03

## Dark Counts	 GaAs MCP-PMT

- ~10-20k cps @ Room Temp.
- < 200 cps at –30°C for operating voltage that gives > 2:1 peak-valley and gain of > 5x105.
- Currently limited by “front-end” noise, not the cathode.
- Slight increase in noise with increasing voltage.

- Estimated Thermionic Curve

- NIST Single Photon Detector Workshop

- 31 March 03

## Timing Data – Single PE 	 GaAs MCP-PMT

_**Rise-Time**_**:**
**< 200ps**
_**Fall-Time**_**:**
**~ 1ns**
- 50 optimized anode design

- NIST Single Photon Detector Workshop

- 31 March 03

## Timing Data – Multiple PE	 GaAs MCP-PMT

_**Anode Rise-Time**_**:**
**~350 ps**
- (using 28ps rise-time laser pulse @636nm)
_**Anode Fall-Time**_**:**
**~    1.5 ns**
*******************************
_**Transit Time Spread**_ **(*****TTS*****):**
**~ 200 ps**

- NIST Single Photon Detector Workshop

- 31 March 03

## Pulsed and DC Linearity 	 GaAs MCP-PMT

**Excellent Pulse **_**Linearity**_**...**
**~ 400mA peak pulse current for < 5% non-linearity.**
**Average DC **_**Linearity**_**...**
**<10% Non-linear @ 500nA**
**(recommended max DC 300nA)**

- NIST Single Photon Detector Workshop

- 31 March 03

## Count Rate Linearity 	 GaAs MCP-PMT

**	****Less than 10% Non-Linearity at 2x10****6**** CPS @ 0.5x10****6**** Gain**
- (counting pulses > 1/3 pe)
**MCP strip Current **
**~3uA**.

- NIST Single Photon Detector Workshop

- 31 March 03

## Lifetime of 85104	 GaAs MCP-PMT

|  |  |  |
| --- | --- | --- |
| Tube Gain | 1x106 | Gain |
| Typical Count Rate | 1x105 | cps |
|  |  |  |
|  |  |  |
| Total Extracted | 7.0 | Coulombs |
| Charge | 4.4x1019 | Electrons |
| 1.2E+05 hrs | 14 years | 1.5x1014 photons (@30% QE) |

***Tube Operating Conditions...***

*Lifetime...*
*(@50% Anode Sensitivity Loss)*

- NIST Single Photon Detector Workshop

- 31 March 03

## Gated Operation	 GaAs MCP-PMT

**Gating the photocathode of the 85104 results in > 10****7**** reduction in sensitivity for white light.**
**Gated PMT via external drive module **_***available***_
**Gated PMT via TTL level gate pulse **_***in development***_**.**
_**Gated Performance Goals**_**: **
**10ns on/off response.**
**On times: 100****’s****ns – 10****’s********s**
**Normally OFF/Gate ON**

- NIST Single Photon Detector Workshop

- 31 March 03

## PlanaconTM MCP-PMT

**2” Duel MCP’s.**
**MultiAnode Designs (currently 2x2, 8x8)**
**Excellent cathode uniformity.**
**Good photon counting properties (peak-valley > 2:1).**
**Compact profile.  Ideal for Tiling Applications.**
**25mm pore size, 40:1 L/D Ratio**

- NIST Single Photon Detector Workshop

- 31 March 03

## MCP-PMT Construction	 PlanaconTM MCP-PMT

- Faceplate

- Anode & Pins

- Indium Seal

- Dual MCP

- MCP Retainer

- Ceramic Insulators

- Spacing between faceplate and MCP and MCP and anode can be varied for different applications

- NIST Single Photon Detector Workshop

- 31 March 03

## Spectral Response	 PlanaconTM MCP-PMT

**BiAlkali Cathode**
**165-660nm**
**Peak @ 410nm**
**Quartz Window for UV transmission**
**Excellent Cathode Uniformity**
**(1:1.2 Typ)**

- NIST Single Photon Detector Workshop

- 31 March 03

## Gain Curves	 PlanaconTM MCP-PMT

***Typical Tube Gain...***
** ****> 5x10****5**

- NIST Single Photon Detector Workshop

- 31 March 03

## Single Electron Resolution	 PlanaconTM MCP-PMT

_**P/V Ratio**_
**2:1 Typical**
_**Single PE Resolution**_
**125% Typical**
_**Dark Count Rate**_
**1K-10K cps**
**(1/3-3 pe ct range)**

- NIST Single Photon Detector Workshop

- 31 March 03

## Uniformity & Cross Talk	PlanaconTM MCP-PMT

**Cathode Uniformity (Typ):**
**1.1:1**
**Anode Uniformity (Typ):**
**1.5:1**
**Cross Talk (Typ):**
**1%**

- NIST Single Photon Detector Workshop

- 31 March 03

## Timing Data – Single PE	 PlanaconTM MCP-PMT

_**Rise-Time**_**:**
**~600ps **
_**Fall-Time**_**:**
**~600ps**

- NIST Single Photon Detector Workshop

- 31 March 03

## Count Rate Linearity	 PlanaconTM MCP-PMT

**~ 10% Non-Linearity at 4x10****6**** CPS @ 0.5x10****6**** Gain**
- (counting pulses > 1/3 pe)
**MCP strip Current **
**~30uA**.

- NIST Single Photon Detector Workshop

- 31 March 03

## Dead Time	 PlanaconTM MCP-PMT

_***Entire PMT***_***...***
- 10% Non-Linearity @ 4M cps
- T = 1/f = 1/4M =.25s
_***Individual Pores***_***...***
- Discharged pore recovers ~??ms
- Millions of pores!!

**Exiting Electrons**

- NIST Single Photon Detector Workshop

- 31 March 03

## Burle MCP-PMT Developments

- Improved anode designs.
- (_Goa_l <200ps rise/fall times).
- Expanded photocathode offering, including InGaAs, Bi-alkali, and Multi-alkali.
- Custom anode designs.
- Reduced pore size and L/D Ratios for reduced deadtime.
- Less resistive MCP’s for higher strip current.

- NIST Single Photon Detector Workshop

- 31 March 03

## Burle Accessories

** ****HV Power Supply**
_***PF1056***_
**Low Noise** (~15mV ripple).
-  Neg. 0-5kV.
- 667uA output current.
- Analog programmable.
- Inherent short circuit protection.

- _Gating Module_
- _Cabling_
- _Thermoelectric Cooler_
- ****
- Visit us @
***www.Burle.com***

- NIST Single Photon Detector Workshop

- 31 March 03

## Comparison with Conventional PMT

| Characteristic | MCP-PMT | Conventional |
| --- | --- | --- |
| Construction | Simple Multiplier | Complex multiplier |
|  | Complex Body | Simple Body |
| Processing | Slow & Complex | Fast & Simple |
|  | “Clean” | “high alkali” |
| Effective QE | Moderate collection efficiency | Good – Excellent Collection efficiency |
|  | > 20% (370 – 870nm) | 25 – 33% peak QE |

- NIST Single Photon Detector Workshop

- 31 March 03

## Comparison with Conventional PMT

| Characteristic | MCP-PMT | Conventional |
| --- | --- | --- |
| Timing Resolution | Excellent, risetime < 200ps | Poor – Very good |
| Open Area | Poor – Moderate with existing designs | Good - Excellent |
| Linearity | Limited average DC current (<1A) | Good–Excellent for DC |
|  | Excellent for pulsed light  | Moderate – very good for pulsed light |

- NIST Single Photon Detector Workshop

- 31 March 03